Study setting {9}
SPIRIT guidance: Description of study settings (eg, community clinic, academic hospital) and list of countries where data will be collected. Reference to where list of study sites can be obtained.
The trial will be implemented in Lower Austria, which is a federal state in northeastern Austria. It is the country’s largest federal state and surrounds the Austrian capital Vienna. Lower Austria had 1,684,287 residents in 2020 (46), which reflects approximately 19% of all inhabitants of Austria (47).
Lower Austria has the second-highest prevalence of diabetes among all Austrian federal states. In this region, 5.7% of all residents above the age of 14 are affected by diabetes (3).
The trainings and medical examinations will be carried out at the St. Pölten University of Applied Sciences (located at the center of Lower Austria) and the hospitals in Wiener Neustadt (in the southeast of Lower Austria), Hollabrunn (in the northwest of Lower Austria) and Mauer/Amstetten (in the southwest of Lower Austria). This equal distribution throughout Lower Austria guarantees easy trial access for all participants. Biochemical analysis will be carried out at the University Hospital St. Pölten (located at the center of Lower Austria).
Eligibility criteria {10}
SPIRIT guidance: Inclusion and exclusion criteria for participants. If applicable, eligibility criteria for study centres and individuals who will perform the interventions (e.g., surgeons, psychotherapists).
Participants eligible for the trial must meet all of the following criteria during randomization:
Inclusion criteria participants (excluding moderators):
- older than 40 years
- living in Lower Austria
- diagnosed with type 2 diabetes mellitus according to the Austrian definition (4)
- HbA1c of ≥ 6.5% (48 mmol/mol) in the most recent measurement
- undergoing standard therapy (4)
- have been receiving oral hyperglycemic agents for a maximum of one year prior to the start of the trial (first prescription of a minimum of two packages per year to exclude wrong prescriptions)
Inclusion criteria moderators:
The inclusion criteria for moderators differ from the inclusion criteria for other participants because moderators are required to be more experienced in the management of their disease in order to be able to authentically share personal and practical experiences and to effectively support participants.
Therefore, they should 1) be interested, 2) be engaged in therapy participation and judged by the practice team as being generally adherent to therapy, 3) have the capacity and commitment to undergo the training, 4) have a complete understanding of the importance of data security and patients’ confidentiality, 5) cooperate with the dietitian and the study team if problems arise, 6) have the ability to fully understand the IMS strategy and the possibilities within the IMS tool, and 7) have several years of diseases experience (no newly diagnosed patients).
Therefore, their inclusion criteria are:
- older than 60 years
- living in the vicinity of the training location in St. Pölten, which means residing in St. Pölten, St. Pölten Land, Melk, Krems, or Lilienfeld
- diagnosed with type 2 diabetes mellitus according to the Austrian definition (4)
- HbA1c of ≥ 6.5% (48 mmol/mol) in the most recent measurement
- undergoing antidiabetic therapy according to the current guidelines (4)
- have been receiving oral hyperglycemic agents for a minimum of three years prior to the start of the trial (first prescription of a minimum of two packages per year to exclude wrong prescriptions)
- engaged participation (regular participation) in the Austrian disease management program ‘Therapie aktiv – Diabetes im Griff’, which is provided by the Austrian Health Insurance Fund
Exclusion criteria for participants as well as moderators:
- neurological or mental illness
- hospitalization of more than 3 weeks during the intervention
- eye disorders that severely limit vision and, hence, inability to read the display (e.g., proliferative retinopathy or macular edema)
- severe illnesses such as kidney, liver, heart disease, or malignant cancer, which make a longer hospitalization likely
- illicit drug use or non-medical use of prescription drugs determined by a single-question screening test for drug use and drug use disorders in primary care (48)
- limited German language skills determined during the initial appointment concerning the informed consent
- pregnancy
Who will take informed consent? {26a}
SPIRIT guidance: Who will obtain informed consent or assent from potential trial participants or authorised surrogates, and how (see Item 32).
Interested participants can register using an online registration form and a central study staff member – a dietitian or a nutritionist – will contact them afterwards.
During the initial appointment, which will be conducted online via MS Teams or face to face at the St. Pölten University of Applied Sciences, the staff member will explain the trial (background, protocol, different roles, importance of randomization and adherence) to potential participants and will review the consent form. Furthermore, the staff member will answer any questions arising. When the trial and its requirements are understood completely, the informed consent form will be signed by the participant. This can be done via electronic or handwritten signature.
All eligible participants must complete the consent procedure before enrolment and randomization. There are separate consent forms for general participants and for moderators.
Compensation
Participants and moderators will get a financial compensation in the amount of 50 EUR and a small gift after the last measurement. Furthermore, the results of the Bioelectrical Impedance Analysis measurements (BIA) in the context of body weight, body height, waist circumference, and blood pressure can be discussed with a dietitian for free after each measurement.
Additional consent provisions for collection and use of participant data and biological specimens {26b}
SPIRIT guidance: Additional consent provisions for collection and use of participant data and biological specimens in ancillary studies, if applicable.
No ancillary study will be conducted.
Interventions
Explanation for the choice of comparators {6b}
SPIRIT guidance: Explanation for choice of comparators.
For the intervention group, we will use the instant messaging tool grape, in addition to standard therapy. grape is an instant messaging application that is installed on the cell phone and works similar to WhatsApp, i.e., people can use grape to send each other messages, photos, etc. Unlike WhatsApp, grape is distributed by an Austrian company and the users’ data are hosted by servers located in Europe in compliance with European data protection regulations. In addition, the use for companies is fee-based.
Intervention description {11a}
SPIRIT guidance: Interventions for each group with sufficient detail to allow replication, including how and when they will be administered.
The intervention is developed and conducted by an interdisciplinary team. Dietitians and moderators play an active role in the operational process of the intervention.
Dietitians are part of the team that develops the training curricula and is responsible for the training of the moderators and participants. They will supervise all moderators once a month via online meetings. During these meetings, the dietitians support moderators, e.g., if specific knowledge concerning diabetes care is needed or in case of technical problems.
Moderators act as facilitators and coordinators but they do not give medical or disease-related advice. In order to moderate communication and exchange in the IMS group effectively and authentically, personal and practical disease-related experiences of the moderator and the readiness to share these experiences with the group are essential. Moderators receive nine hours of training on the content to be shared via IMS and communication strategies to facilitate group exchange, peer support and behavioral change.
Participation in the clinical trial will last 15 months (1 month training/first measurement, 7 months intervention, 7 months follow-up). 196 participants will be randomly assigned to one of two groups: the intervention group or the control group. Participants who are randomly assigned to the intervention group will attend a two-hour technical training in connection with the first measurement. In the course of this training, they will learn how to use the grape app (https://www.grape.io/de/). After this training, they will join a grape group (Instant Messaging Service group) with a maximum of 14 people for 14 months (seven months guided and seven without guidance). For the first seven months of the intervention, an empowerment-based IMS communication strategy for diabetes self-management peer support has been developed.
Moderators are provided with a detailed handbook on web-based diabetes-related content and communication strategies to share this content with the group.
The IMS strategy combines two aspects that are essential for IMS diabetes self-management peer support: 1. a communication strategy that takes into account the special requirement of IMS communication, i.e., approaches to raise engagement and activities in the group, and 2. a diabetes self-management support strategy to make sure that all topics which are known to be of importance for diabetes self-management (49) are covered and shared in a way that enables and empowers participants in their disease management. Thus, the IMS communication strategy contains, on the one hand, the IMS strategy which also involves a communication strategy that considers the special requirements of IMS and peer-communication on how to react and act in certain situations, for example to achieve engagement. On the other hand, it entails a didactic plan which outlines how, in what form and how frequently diabetic content shall be shared with the participants by moderators (e.g., web links, exchange of personal experiences/opinions). This IMS strategy will be operationalized in form of the training curriculum.
The moderator and the way she or he communicates with the group plays a vital role in guiding the group, setting the tone and creating an atmosphere of trust and providing support. By introducing the moderators to certain communication strategies that are also displayed in detail in the guidebook and can be reflected upon in the monthly meeting with the dietitian, a trusting atmosphere in the IMS group should be facilitated.
After the intervention, a seven-month follow-up will be conducted. During the follow-up, the intervention group may use the IMS tool in a self-organized manner, i.e., without guidance by the dietitian, and continue to receive their standard therapy.
Participants who are assigned to the control group will continue to receive their standard therapy but will not be assigned to a grape group.
The intervention will be conducted twice to increase the recruitment phase. The first intervention will start in January 2022. As soon as the first cohort enters the unaccompanied phase, a second moderated cohort will start – in both cases accompanied by an equally large control group. In total, we will be in the field for 23 months. With the start of the first intervention, we will have as many intervention and control teams with 14 people each as there are registrations. With the second intervention date, the remaining persons (196 in total) form further intervention and control teams.
Criteria for discontinuing or modifying allocated interventions {11b}
SPIRIT guidance: Criteria for discontinuing or modifying allocated interventions for a given trial participant (eg, drug dose change in response to harms, participant request, or improving/worsening disease).
Participants can revoke their willingness to participate at any time, even without giving reasons, and withdraw from the clinical study without this causing them any disadvantages for their further medical care.
The principal investigator may terminate a participation in the study prematurely without obtaining the participant's consent beforehand. The reasons for this may be:
(a) participants do not longer meet the inclusion requirements of the clinical trial
b) the treating doctor reasons that continued participation in the clinical trial is not in the participant’s best interest
(c) the study coordinator makes the decision to terminate the entire clinical trial, or to terminate only one subject's participation prematurely
The communication protocols (see also {12}) based on activities within the IMS tool grape are reviewed weekly. The results of these reviews are used – in addition to the planned analysis of the KPIs – to monitor the intervention group and to intervene if necessary. Thus, they help the study coordinator and selected study team members to stay informed and, in case of extraordinary events (e.g., mobbing), to decide whether to continue, modify, or prematurely terminate the work with certain participants, moderators or communication concepts. If a participant does not adhere to the communication rules (netiquette) previously agreed upon in each IMS group – even after several discussions – he or she will be excluded.
Strategies to improve adherence to interventions {11c}
SPIRIT guidance: Strategies to improve adherence to intervention protocols, and any procedures for monitoring adherence (eg, drug tablet return, laboratory tests).
The intervention consists of a peer-supported IMS intervention in addition to standard therapy. Therefore, adherence of participants to the IMS intervention pertains mainly to the IMS strategy, the measurements and the initial training sessions.
The first step to improve adherence is the holistic explanation of the trial to interested participants during the initial appointment (50,51). In this appointment, sufficient time is scheduled in order to enable comprehensive understanding concerning the trial among participants.
Those who have greater responsibility – the moderators – will be individuals participating in the disease management program ‘Therapie aktiv – Diabetes im Griff’ (https://www.therapie-aktiv.at), which is provided by the Austrian Health Insurance Fund. Hence, they are already proven to be generally adherent and engaged in their disease management. These moderators will positively influence their group members through the role model effect.
A dietitian experienced in counseling will support the moderators if problems arise and they will supervise all moderators once a month via online meetings. During the supervision, the dietitian will reflect on the past month and discuss the next steps of the IMS strategy with the moderators. If necessary, the communication expert can provide further assistance during these meetings.
Furthermore, we expect an additional positive social effect: participants will identify with their grape group and, in the next step, with the DiabPeerS trial. Hence, they will be interested in a successful intervention and participate actively. Also, frequent personal contact between the central study staff (EH, MH, AEZ) and the participants throughout the whole trial (initial appointment, four measurements, supervision meetings) will support adherence (50).
The IMS strategy (see {11a}), the core element of this trial, aims to improve diabetes self-management. Taking into consideration that regular medical appointments and monitoring are central in diabetes self-management, we assume that this increasing competence will support adherence to intervention as well.
Additionally, clinical visits will be designed as convenient for the participants as possible (50,51). The participants will have easy access to the locations of training sessions and measurements: they can choose one out of four central locations in Lower Austria for their measurements. These locations are well known and easily accessible: the St. Pölten University of Applied Sciences and hospitals in Wr. Neustadt, Hollabrunn, and Mauer/Amstetten. These locations are equally distributed over Lower Austria from a geographical point of view and can be reached comfortably by car as well as public transport. The training sessions for the participants will take place after the first measurement at the same location. The training sessions for the moderators will be held at the St. Pölten University of Applied Sciences. Therefore, only individuals from St. Pölten or the surrounding areas are eligible to become moderators. If a participant misses one measurement, it is possible to make a new appointment within a certain timeframe.
Furthermore, study staff will call participants to schedule visits and send them reminders via SMS and e-mail 48 hours before the appointment. During each measurement, participants and moderators will have the opportunity to discuss their results, such as body composition, with an experienced dietitian, which is not very common in Austria and will increase engagement (50).
Additionally, participants and moderators will receive a financial compensation of 50 EUR and a small gift after the last measurement.
Relevant concomitant care permitted or prohibited during the trial {11d}
SPIRIT guidance: Relevant concomitant care and interventions that are permitted or prohibited during the trial.
All participants should proceed with their standard therapy (4), and the moderato rs should continue to participate in the disease management program ‘Therapie aktiv – Diabetes im Griff’ (https://www.therapie-aktiv.at) (52) during the trial.
It is also possible for participants to subscribe to the disease management program ‘Therapie aktiv – Diabetes im Griff’ during the trial. This program was launched in Austria in 2007 and aims to organize long-term and high-quality care for patients with diabetes mellitus type 2. It is voluntary and free of charge for physicians as well as for patients. It implements evidence-based clinical guidelines and supports patient empowerment, regular medical examinations, and lifestyle advice (52). At the end of 2020, 1,4976 patients with diabetes mellitus type 2 and 296 doctors in Lower Austria – or 93,099 patients with diabetes mellitus type 2 and 1,917 doctors at the national level – participated in this disease management program according to internal data of the Austrian Health Insurance Fund.
Provisions for post-trial care {30}
SPIRIT guidance: Provisions, if any, for ancillary and post-trial care, and for compensation to those who suffer harm from trial participation.
Trial participation entails only minimal risk compared to standard therapy alone, which will be continued after the trial. Therefore, no special provisions for post-trial care are included.
Outcomes {12}
SPIRIT guidance: Primary, secondary, and other outcomes, including the specific measurement variable (eg, systolic blood pressure), analysis metric (eg, change from baseline, final value, time to event), method of aggregation (eg, median, proportion), and time point for each outcome. Explanation of the clinical relevance of chosen efficacy and harm outcomes is strongly recommended.
The primary outcome is the level of HbA1c [%] measured using TOSOH G8 (Sysmex Austria GmbH).
Secondary outcomes are:
Psychosocial parameters:
- Social support will be measured using the ‘Fragebogen zur Sozialen Unterstützung‘ (F-SozU) (53): the F-SozU operationalizes social support as perceived or anticipated support from the social environment. The short form consists of the following subscales: ‘emotional support’, ‘practical support’, ‘social integration’, ‘stress from the social network’. The F-SozU involves of 14 items using a five-point Likert scale with the endpoints ‘1’ (does not apply) and ‘5’ (accurate).
- Self-efficacy will be measured using the ‘General Self-Efficacy Scale‘ (GSE) (54): the GES consists of ten items designed on a four-point Likert scale with the endpoints ‘1’ (not at all true) and ‘4’ (exactly true) and assesses optimistic self-beliefs to cope with several challenges in life.
- Depression will be measured using the ‘Patient Health Questionnaire-9‘ (PHQ-9) (55): the PHQ-9 asks for all nine criteria of depression as defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) using a four-point Likert scale with the endpoints ‘0’ (not at all) and ‘3’ (nearly every day).
- Diabetes distress will be measure using the ‘Diabetes Distress Scale‘ (DDS) (56): the DDS includes for dimensions of distress (‘emotional burden’, ‘regimen distress’, ‘interpersonal distress’, ‘physician distress’). The DDS consists of 17 items using a six-point Likert scale with the endpoints ‘1’ (not a problem) and ‘5’ (a very serious problem).
- Quality of life will be measured using the ‘Short-Form-Health Survey‘ (SF-12) (57): the SF-12 includes eight dimensions (‘physical functioning’, ‘role limitations due to physical problems’, ‘bodily pain’, ‘vitality’, ‘general health perceptions’ , ‘social functioning’, ‘role limitations due to emotional problems’, ‘mental health’). The summary scores ‘physical component summary’ and ‘mental component summary’ (0-100 scales) can be calculated from the specified scales.
- Diabetes knowledge will be measured using the ‘Diabetes Knowledge Test‘ (DKT) (58) with forward and retranslation: the DKT consists of 20 statements about diabetes which have to be rated as ‘true’, ‘false’ or ‘don’t know’. Based on the answers, a difficulty index (percent of patients who scored correctly) is calculated.
Behavioral parameters:
- Medication adherence will be measured using the ‘A14-scale‘ (59): the A14 consists of 14 items of non-adherent behaviors phrased in a non-threatening and non-judgemental way using a five-item Likert scale with the endpoints ‘4’ (never) to ‘0’ (very often).
- Dietary behavior and alcohol consumption will be measured using the food frequency questionnaire developed for the German Health Examination Survey for Adults 2008-2011 (DEGS-FFQ) (60,61): the semi-quantitative DEGS-FFQ assess ‘dietary behavior’ including ‘alcohol consumption’ during the past four weeks.
- Smoking will be measured using the questionnaire ‘Aktivrauchen – Kurzversion (Erwachsene)’ (62): the questionnaire assesses the current smoking behavior per week and that of the last six months. Participants indicate the number of cigarettes, cigarillos, cigars, or amount of tobacco (grams) used for pipes or hand-rolled cigarettes.
- Physical activity will be measured using the ‘International Physical Activity Questionnaire Short Form‘ (IPAQ-SF) (63,64): the IPAQ-SF asks seven questions to assess ‘vigorous-intensity’ and ‘moderate-intensity’ physical activity as well as ‘walking’ and ‘sitting’. Participants indicate the time in minutes or hours for each activity level. Based on this information, three levels of physical activity (low, moderate, high) are calculated and expressed in metabolic equivalent of task (MET) minutes per week.
- Diabetes self-management behaviors will be measured using the ‘Summary of Diabetes Self-Care Activities German‘ (SDSCA-G) (65): the SDSCA-G focuses on the past seven days related to the diabetes self-care activities ‘nutrition’, ‘physical activities’, ‘blood glucose testing’, ‘foot care’, and ‘smoking’. The SDSCA-G consists of 11 items and participants mark the number of days the mentioned behavior was performed on an eight-point Likert scale with the endpoints ‘0’ (0 days) to ‘7’ (7 days). Whilst the first ten items are calculated to a score and four sub scores (diet, exercise, blood-glucose testing, foot care), the eleventh item focuses on smoking habits.
- Clinic and communication visits (health professional visits in the past six months, hospital stays in the past six months).
Biochemical parameters:
- Fasting blood glucose [mg/dl] as measured using Cobas 8000 (Roche Austria GmbH)
- Total cholesterol [mg/dl] as measured using Cobas 8000 (Roche Austria GmbH)
- High-density lipoprotein (HDL) [mg/dl] as measured using Cobas 8000 (Roche Austria GmbH)
- Low-density lipoprotein (LDL) [mg/dl] and triglycerides [mg/dl] as measured using Cobas 8000 (Roche Austria GmbH)
- Blood pressure [mmHg] as measured using Boso Medicus uno OA
- Body weight [kg] and body height [cm] to calculate the body mass index (BMI: body weight in kilograms/height in meters squared) as measured using the Seca bella 840 scale and Seca 214 stadiometer
- Body fat [%] as measured using Aengus BIACORPUS RX 4004M and BodyComp V 9.0 Professional (both MEDI CAL HealthCare GmbH, Karlsruhe)
- Waist circumference [cm] to calculate the waist-to-height ratio as measured using an ergonomic, step less, and extendible measuring tape
Additionally, demographic data and personality traits will be surveyed in the baseline assessment (T0). Demographic data include age, gender, education, living arrangement (marital status), income, employment status, immigration background (66), and clinical information (age at diagnosis, on insulin, other medical therapies, list of prescribed medications). Personal traits will be assessed using the Big Five Inventory German (BFI-2) (67). The BFI-2 captures ‘extraversion’, ‘agreeableness’, ‘conscientiousness’, ‘negative emotionality’ and ‘openness’, each represented by three sub-facets. The BFI-2 consists of 60 items using a five-item Likert scale with the endpoints ‘1’ (strongly disagree) to ‘5’ (strongly agree).
Additionally, participation in the disease management program ‘Therapie aktiv – Diabetes im Griff’ as well as pregnancy will be evaluated at each measurement.
Communication data (real-time):
As part of the data export solution of the IMS communication data, an export script is provided in which individual rooms – these correspond to the groups assigned for the experiment – are listed. Such communication protocols containing the communication data of the individual groups can be retrieved on a daily basis. These data include, for example, the persons who have sent a post, sent texts and files, timestamps or quotes. This information will be used to quantify the IMS communication activities.
The posts will be evaluated by content analysis to explain and interpret the results of (H2) diabetes self-management behaviors, (H3) quality of life of participants, and (H4) medication adherence of participants. The codebook will be developed in collaboration with medical professionals for the coding of adherence and non-adherence behaviors. The quantified data will then be made available for the in-depth analysis of questionnaire data and medical scores.
According to past research (68–70), personality traits such as extraversion can influence our communication behavior: extraverted individuals speak more often, make more eye contact, smile and nod more frequently than introverted persons. (H5) Therefore, we assume that extraversion will correlate positively with the number of posts as well as the number of reactions and emojis to posts from others.
Participant timeline {13}
SPIRIT guidance: Time schedule of enrolment, interventions (including any run-ins and washouts), assessments, and visits for participants. A schematic diagram is highly recommended (see figure at http://www.spirit-statement.org/publications-downloads/).
The flow diagram showing the participant timeline through the DiabPeerS study is presented in Fig.1. The SPIRIT figure for this trial is given in Fig.2.
Sample size {14}
SPIRIT guidance: Estimated number of participants needed to achieve study objectives and how it was determined, including clinical and statistical assumptions supporting any sample size calculations.
An a priori calculation was performed using G-Power (71) for the primary outcome variable HbA1c, using an ANCOVA at 5% level of significance and 80% power. Based on previous research, we assumed a small to medium effect size for group differences in HbA1c means (partial eta squared = 0.05, which corresponds to an effect size f = 0.229) (72–74). Considering a 30% dropout ratio, we will include 98 randomly assigned participants in each group (196 total). The intervention group will be subdivided into seven IMS groups made up of 14 participants and one moderator each. Therefore, nine moderators (seven plus two for the compensation of possible drop-outs) will be additionally recruited (205 persons in total, 196 participants plus nine moderators). Although the moderators will participate in the assessments, their data will not be included in the analyses.
Recruitment {15}
SPIRIT guidance: Strategies for achieving adequate participant enrolment to reach target sample size.
The Austrian Health Insurance Fund will perform a FoKo database (Folgekosten database) query based on defined inclusion and exclusion criteria to identify potential participants in Lower Austria.
The FoKo database is a social insurance data warehouse that is used by all health insurance providers in Austria. FoKo combines several IT (accounting) systems of Austrian health providers in one instrument and thus enables various analyses. FoKo collects data related to medical assistance, medication, and incapacity to work as well as in-patient stays or patient transport and dental treatment. FoKo has registered approximately 1.2 million people eligible for services of the Austrian Health Insurance Fund in Lower Austria.
Based on FoKo database queries of the years 2018 and 2019, approximately 6,000 potential participants will be identified. The data of the Mother-Child-Booklet, which is part of the Austrian pregnancy and childhood examinations, allows to identify pregnant women (with gestational diabetes) in order to exclude them from the study (75). The Austrian Health Insurance Fund will contact all identified patients with diabetes mellitus type 2 by personal letter while strictly considering data privacy. Additionally, the Austrian Health Insurance Fund will inform all relevant physicians and internists in Lower Austria about the trial and ask them to inform their patients about the possibility to participate in the trial. Furthermore, the diabetes-specific self-help organizations ADA (https://aktive-diabetiker.at/) and ÖDV (https://www.diabetes.or.at/home/) will inform their members about the trial. Additionally, leaflets will be disseminated at the Customer Service Centers of the Austrian Health Insurance Fund and via the consortium member institutions’ online channels, e.g., their websites.
Assignment of interventions: allocation
Sequence generation {16a}
SPIRIT guidance: Method of generating the allocation sequence (eg, computer-generated random numbers), and list of any factors for stratification. To reduce predictability of a random sequence, details of any planned restriction (eg, blocking) should be provided in a separate document that is unavailable to those who enrol participants or assign interventions.
Eligible participants who have signed the informed consent will be randomized into the peer-supported IMS intervention group or the control group in a 1:1 ratio. Random assignment will be conducted using virtual urn randomization during the initial appointment.
Concealment mechanism {16b}
SPIRIT guidance: Mechanism of implementing the allocation sequence (eg, central telephone; sequentially numbered, opaque, sealed envelopes), describing any steps to conceal the sequence until interventions are assigned.
For the allocation of the participants, a simple urn-based randomization is carried out. For this purpose, an urn, in our case a digital card set, is filled with 196 cards. On 98 of them, it says ‘intervention group’ and on 98 ‘control group’. A unique ID is assigned to each card. The participants draw the cards themselves. This gives them the feeling that they have made their own decision and makes it easier for them to accept it, even if they do not end up in the desired group.
Implementation {16c}
SPIRIT guidance: Who will generate the allocation sequence, who will enrol participants, and who will assign participants to interventions.
The drawing of the participants takes place during the initial appointment for the informed consent. Since the participants come continuously and from all over Lower Austria, interviews are conducted both in person and via video calls. In order to make the ballot box drawing online and offline comparable, a computer-based drawing will take place in both cases, i.e., similar to a memory game. The test persons turn over one (of 196) cards and thus find out in which group they participate and, at the same time, receive their ID for the study. The drawing takes place without putting the cards back.
The maximum group size is 14 participants. When an intervention or control group is full, the recruitment of the next group will be started. The ID numbers are therefore not consecutive within the groups, but random. There is no upper limit regarding the number of participants for the first recruitment date.
Assignment of interventions: Blinding
Who will be blinded {17a}
SPIRIT guidance: Who will be blinded after assignment to interventions (eg, trial participants, care providers, outcome assessors, data analysts), and how.
Blinding of trial participants will not be possible because of the obvious differences between the intervention group and the control group. Blinding will be implemented for the medical staff and the outcome assessors of the measurements and the following analyses (see {19}).
Procedure for unblinding if needed {17b}
SPIRIT guidance: If blinded, circumstances under which unblinding is permissible, and procedure for revealing a participant’s allocated intervention during the trial.
It is an open-label study and therefore unblinding will not occur.
Data collection and management
Plans for assessment and collection of outcomes {18a}
SPIRIT guidance: Plans for assessment and collection of outcome, baseline, and other trial data, including any related processes to promote data quality (eg, duplicate measurements, training of assessors) and a description of study instruments (eg, questionnaires, laboratory tests) along with their reliability and validity, if known. Reference to where data collection forms can be found, if not in the protocol.
During the online registration, contact data of all interested individuals will be collected. The data will be deleted if the person disagrees to participate in the trial.
Data will be collected four times over a period of 14 months: at baseline (T0), three months after the start of the intervention (T1; T0+3 months), at the end of the intervention (T2; T0+7 months), and after the follow-up (T3; T0+14 months), including the collection of biochemical, psychosocial, and behavioral parameters as described in the subsection ‘Outcomes (see {12})’ during all four data collection points.
All parameters will be taken in a group testing setting with appropriate Coronavirus SARS-CoV-2 (COVID-19) safety measures, e.g., testing, vaccination, hygiene procedures by the staff of the St. Pölten University of Applied Sciences either at the university itself or at the Landesklinikum Wr. Neustadt, Hollabrunn, or Mauer/Amstetten.
The measurements will take place in the morning in a fasting state and with anthropometric measurements with light clothing. Anthropometric measurements will be conducted by dietitians. Blood pressure und blood samples will be taken by nurses. Fresh blood samples will be taken by the staff of the St. Pölten University of Applied Sciences and analyzed within a timeframe of three hours maximum by the University Hospital St. Pölten. Therefore, blood samples will be taken at the end of each data collection session and will be brought immediately to the University Hospital St. Pölten without interrupting the cold chain. The laboratory of the University Hospital St. Pölten is ISO 9001-certified and will handle all samples according to its quality management.
Plans to promote participant retention and complete follow-up {18b}
SPIRIT guidance: Plans to promote participant retention and complete follow-up, including list of any outcome data to be collected for participants who discontinue or deviate from intervention protocols.
To minimize loss during the follow-up, and in order to promote participation in the follow-up measurements, the same strategy is implemented as for compliance with the intervention measurements (see {11c}): as convenient as possible, reminders 48h ahead of the measurement, possibility to discuss the measurements’ results with the dietitian, and a financial compensation paid after the last measurement.
During the follow-up, participants of the intervention group can use the messenger service and continue their communication with the group members and the moderator, hence, without support of the study team. The moderator will be instructed to motivate the group members to participate in the follow-up measurement. The relationship of trust and social support in the groups as well as with the study staff will support a higher degree of complete follow-up.
Data management {19}
SPIRIT guidance: Plans for data entry, coding, security, and storage, including any related processes to promote data quality (eg, double data entry; range checks for data values). Reference to where details of data management procedures can be found, if not in the protocol.
The participants agree that for the purpose and in the course of this study, the St. Pölten University of Applied Sciences will collect and process the following personal data: name, age, gender, education, income, occupational situation, housing situation, migration background, personality characteristics, clinical information such as age at diabetes diagnosis, social support, self-efficacy, depression, quality of life, diabetes knowledge, treatment adherence, diet and exercise behavior, nicotine and alcohol consumption, diabetes self-management, medical consultations during the last six months, HbA1c, fasting glucose, total cholesterol, HDL, LDL, triglycerides, blood pressure, body weight and height, abdominal circumference, and body composition.
Furthermore, the participants agree that the University Hospital St. Pölten may transmit the following data in indirectly personalized (pseudonymized or encrypted) form to the St. Pölten University of Applied Sciences for the purpose of analyzing whether the intervention is effective with regard to the defined parameters compared to conventional therapy: HbA1c, fasting glucose, total cholesterol, HDL, LDL, triglycerides.
The participants’ data will be pseudonymized and assigned a fixed identification code. This code will be stored safely in a password-protected file, accessible only by the study coordinator (EH) and central staff members (UH, AEZ). The key for the coding is kept separately and inaccessibly by the study coordinator. Thus, it is only possible for persons who are entrusted with the evaluation of the data to infer the identity of the participants.
Data acquisition and data processing are performed using commercial software. All data obtained are stored in computer files in encrypted form. The coding is done by means of consecutive numbering, from which only the allocation to the corresponding group, but in no case a conclusion as to the identity of the participant is possible.
Data will be stored and analyzed via the statistical software package SPSS at servers of the St. Pölten University of Applied Sciences, only used for this special study and not be passed on to third parties. The handling of the data complies with the European General Data Protection Regulation, the Austrian Data Protection Act and the recommendations of the Ethics Committee of Lower Austria.
To be able to merge the data from the paper-and-pencil questionnaires, anthropometric measurements and the blood pressure data, a defined coding system will be used. Therefore, the study coordinator will take part in every measurement and organize the participants and coding system. Hence, every participant will get his or her identification code and the questionnaires will be marked with this code at the beginning of each measurement. The identification code ensures that the study staff do not know to which group each participant belongs. Paper-and-pencil questionnaires will be checked by the study staff in terms of completeness and correctness related to the specifications of the questionnaires. These data will be transferred into SPSS manually and controlled by another member of the study team. Results of the biochemical analysis will be mailed via encrypted Excel files from the University Hospital St. Pölten to the St. Pölten University of Applied Sciences and imported into SPSS by the study coordinator. Blood samples will be disposed of and Excel files will be deleted after integration into SPSS. Furthermore, the St. Pölten University of Applied Sciences performs data back-ups on a daily basis. All signed informed consent forms as well as all collected paper-and-pencil sheets will be stored in a locked place, accessible only to the study coordinator and a central staff member (UH). All data will be stored at the St. Pölten University of Applied Sciences for ten years after the study’s end. After that, all data will be destroyed.
To ensure data quality, the study coordinator will control the data regularly including checking the range of values or double data entry.
Data protection concerning the instant messaging tool will be met by using the instant messaging communication tool grape (https://www.grape.io/de/). grape has been chosen for its clear terms and conditions and data handling strategy. grape offers a fully transparent and documented communication infrastructure that stores cloud data in Austria.
grape is an Austrian technology start-up based in Vienna that provides a holistic messaging solution that allows companies to communicate securely and efficiently via chats, video, voice calls and screen sharing internally and externally. For our study, the grape communication platform (software solution) is hosted by a European data center near Vienna (ISO27001:2013 certified). The data export based on Docker is conducted in grape’s data center and made available only to selected members of the study team (EH, AEZ, JG). The data are cleaned, and unstructured communication data will be structured using content analysis and MAXQDA (see {12}). Subsequently, these data will be pseudonymized and transferred into SPSS for further analysis.
Results of all analyses will be reported in an aggregated and strictly anonymous form.
Confidentiality {27}
SPIRIT guidance: How personal information about potential and enrolled participants will be collected, shared, and maintained in order to protect confidentiality before, during, and after the trial.
All collected data will be kept confidential as described in ‘Data management’ (see {19}). Only the study coordinator and central staff members (UH, AEZ) can open the password-protected file to link personal information and code. The final pseudonymized dataset in SPSS will be used by the study staff for analyses, publications, and reports only for this study.
Plans for collection, laboratory evaluation and storage of biological specimens for genetic or molecular analysis in this trial/future use {33}
SPIRIT guidance: Plans for collection, laboratory evaluation, and storage of biological specimens for genetic or molecular analysis in the current trial and for future use in ancillary studies, if applicable.
Not applicable as no biological specimens for genetic or molecular analysis will be collected.
Statistical methods
Statistical methods for primary and secondary outcomes {20a}
SPIRIT guidance: Statistical methods for analysing primary and secondary outcomes. Reference to where other details of the statistical analysis plan can be found, if not in the protocol.
Data will be analyzed using IBM SPSS Statistics 26 or greater (IMB Corporation, Armonk, NY, USA). The significance level will be set at 5%. Generally, metric data will be checked for normal distribution using a histogram of each variable, as well as for skewness and kurtosis. To illustrate descriptive parameters, the arithmetic mean and the 95% confidence interval will be stated for metric data. Interval variables or nominal scaled variables will be shown as frequencies. Repeated measures ANCOVA will be used to compare the control and intervention groups concerning primary and secondary outcome parameters. Non-normal metric data will be analyzed using the Mann-Whitney U test, the Kruskal-Wallis signed rank test or the Friedman-Test (76).
Interim analyses {21b}
SPIRIT guidance: Description of any interim analyses and stopping guidelines, including who will have access to these interim results and make the final decision to terminate the trial.
There will be no planned interim analysis or stopping guidelines for medical reasons besides the exclusion criteria (see {10}) because no potentially harmful outcomes are expected based on the peer-supported IMS intervention. Nevertheless, participants can be excluded from the intervention group if they do not follow the rules of interaction set and agreed upon in the IMS group (see {11b}).
Methods for additional analyses (e.g. subgroup analyses) {20b}
SPIRIT guidance: Methods for any additional analyses (eg, subgroup and adjusted analyses).
As we want to assess the association between specific personality traits and the benefits of peer-supported IMS, we use validated and published questionnaires, which we repeatedly distribute to all experimental and control groups at different times of the study.
In addition to the observed communication behavior, we use the information from the questionnaires (see {12}) to test the hypotheses and in particular related to (H2) diabetes self-management behaviors, (H3) quality of life of participants, and (H4) medication adherence as well as (H5) the level of extraversion.
Methods in analysis to handle protocol non-adherence and any statistical methods to handle missing data {20c}
SPIRIT guidance: Definition of analysis population relating to protocol non-adherence (eg, as randomised analysis), and any statistical methods to handle missing data (eg, multiple imputation).
All participants’ data will be analyzed following the intention-to-treat principle. Scores for scales with at least 80% of items responded will be analyzed. For these cases, the nearest neighbour method will be used to replace missing data points. Furthermore, we will check the randomness of missing data by calculating the MCAR (missing completely at random) classification.
Plans to give access to the full protocol, participant level-data and statistical code {31c}
SPIRIT guidance: Plans, if any, for granting public access to the full protocol, participant-level dataset, and statistical code.
It is not planned to give third parties access, neither to the full protocol, nor the participant data, nor the statistical code.
Oversight and monitoring
Composition of the coordinating centre and trial steering committee {5d}
Trials guidance: Provide information on the composition, roles and responsibilities of the coordinating centre and trial steering committee and all groups providing day to day support for the trial. There will always be a group running the trial day-to-day and providing organisational support and knowing how often they will meet, plus information on other committees providing oversight such as a Trial Steering Committee, and how often they will meet over the course of the trial, is what we need for item 5d. We do not need names of staff.
SPIRIT guidance: Composition, roles, and responsibilities of the coordinating centre, steering committee, endpoint adjudication committee, data management team, and other individuals or groups overseeing the trial, if applicable (see Item 21a for data monitoring committee).
The complexity of diabetes therapy demands interdisciplinary teams and innovative treatment approaches. This consortium meets these requirements and combines life sciences, nutritional sciences & dietetics, human medicine, psychology and with media economics, communications and sociology in a unique constellation. Responsibilities are assigned on the basis of the expertise of the respective study team members. Responsible persons for the following areas are defined as relevant to the study: Instant Messenger Interventions, Dietetics, Medical Measurements, Recruitment, and Biochemical Analyses and Statistics. In addition, two persons are available as supervisors for the areas of Nutrition and Communication, respectively, and a medical doctor is also part of the study team.
Meetings of the entire study team are held every two months or more frequently when meetings are needed, or in subgroups. In addition, experts are available on request. Decisions are made democratically. The study coordinator has the final responsibility.
Ethics approval has been obtained from the local Ethics Committee prior to the start of the study (see {24}). Technical know-how is mainly outsourced to the service units of the messenger service grape.
Composition of the data monitoring committee, its role and reporting structure {21a}
SPIRIT guidance: Composition of data monitoring committee (DMC); summary of its role and reporting structure; statement of whether it is independent from the sponsor and competing interests; and reference to where further details about its charter can be found, if not in the protocol. Alternatively, an explanation of why a DMC is not needed.
A Data Monitoring Committee (DMC) has been established (EH, AEZ, UH, JG).
On the one hand, the role of the committee members (AEZ, JG) is to conduct weekly checks of the communication protocols and to identify potential errors in measurement or possible anomalies in the behaviors of participants and moderators.
In addition, members of the DMC (EH, UH) routinely check that adequate procedures are in place to ensure that the data remain confidential and that there are no data breaches. If security problems are identified, the Data Monitoring Committee informs the other study members or, depending on the severity of the problem, also the funding agency, and takes action to fix the problem.
Adverse event reporting and harms {22}
SPIRIT guidance: Plans for collecting, assessing, reporting, and managing solicited and spontaneously reported adverse events and other unintended effects of trial interventions or trial conduct.
Although we consider specific risks for participation very low, a system for collecting, assessing, reporting, and managing adverse events will be implemented. Every potential adverse event will be documented in detail. The study coordinator will immediately inform the Ethics Committee of Lower Austria and the study’s insurance company if necessary.
If a problematic situation arises in an IMS group such as bullying, depression, racial/sexist/homophobic etc. statements, extensive sharing of fake news, commercials and the like, the moderator can try to solve it using the communication strategies learned during the training, discuss it with the dietitian and/or other moderators, or hand over the problem to the dietitian and/or the study staff. Furthermore, the study team will control the communication data for problematic situations at regular intervals. The dietitians will address this topic during the monthly meetings with the moderators as part of the process evaluation.
Frequency and plans for auditing trial conduct {23}
SPIRIT guidance: Frequency and procedures for auditing trial conduct, if any, and whether the process will be independent from investigators and the sponsor.
Not applicable as there are no planned audits.
Plans for communicating important protocol amendments to relevant parties (e.g. trial participants, ethical committees) {25}
SPIRIT guidance: Plans for communicating important protocol modifications (eg, changes to eligibility criteria, outcomes, analyses) to relevant parties (eg, investigators, REC/IRBs, trial participants, trial registries, journals, regulators).
Approval for protocol modification will be sought for from the Ethics Committee of Lower Austria as well as the funding organization (Gesellschaft für Forschungsförderung Niederösterreich m.b.H, Austria). Upon approval of all changes, they will be noted in the study registration. If protocol modifications differ from what was explained to participants when signing the informed consent, the participants will be informed immediately about all changes and re-consent will be sought by a study staff member (dietitian or nutritionist).
Dissemination plans {31a}
SPIRIT guidance: Plans for investigators and sponsor to communicate trial results to participants, healthcare professionals, the public, and other relevant groups (eg, via publication, reporting in results databases, or other data sharing arrangements), including any publication restrictions.
The consortium has developed a dissemination plan which defines all relevant stakeholders and appropriate dissemination strategies as well as authorship guidelines (77) visualized in a GANTT chart including when to conduct which dissemination activity, and another tool for the documentation of all activities. The dissemination plan includes scientific as well as general dissemination activities.
All dissemination activities will be documented and reported by the responsible consortium member. When it comes to scientific dissemination, the study protocol and the study results will be published in peer-reviewed open access journals. The study and its results will be presented at scientific conferences. Various activities are planned to disseminate generally, e.g., at special events like the “European Researchers’ Night” or at the “World Diabetes Day”, study website posts, press releases or radio and TV contributions.