Design
We conducted an analytic cross-sectional study with data on individual and organizational variables in 12 general hospitals in Thailand using multi-stratified sampling based on Thailand's health service system administration [29]. There are 3 clusters comprised of community hospitals, advanced and standard hospitals, and university hospitals. To achieve an equal sample size in all groups, the number of participants in all clusters was 150. The hospitals in each grouping cluster were selected by purposive sampling.
Sample size
Based on the rule of thumb concerning the relationship between sample size and model complexity, which also has some empirical support as the N:q rule, an ideal sample size-to-parameters ratio would be 20:1 [30]. This study has ten parameters, so the sample size is 10×20 = 200, and adjusting for design effect to compensate for the cluster sampling of 2; there were 200×2 = 400 cases [31]. Hence, the design effect's final sample size was at least 400.
Setting
Thailand is an upper-middle-income country located in South-East Asia. Policy and strategic plan for mental health service system in Thailand complied with WHO action plan and is making progress towards meeting the SDG 3. People at risk of depressive disorders are screened to provide early intervention. Older persons with chronic illness are identified as a high-risk group and are monitored by screening when they visit for annual service at the general hospital. Regarding the Thai health service system, available health facilities delivering services to people are classified according to a three-tier service system: primary, secondary, and tertiary care facilities [32]. The primary healthcare facility is the first contact individuals, families, and communities have with the health care system. Service provision emphasizes health promotion and prevention.
Secondary health care facilities provide curative care with initial referrals from primary care professionals. Health service provision is more complex and requires higher medical expertise. Such health facilities include the Ministry of Public Health (MoPH) community hospitals, other public hospitals, and private hospitals. The tertiary health care facilities provide specialized investigation and treatment, usually on referral from primary or secondary medical care personnel. The facilities include MoPH general (standard) and regional (advance) hospitals, university hospitals, other public hospitals, and private hospitals. Mental health services for people with depressive disorders are usually provided treatment and care at secondary and tertiary care facilities because there are physicians to investigate, diagnose and prescribe antidepressant drugs. In addition, they have specialty mental health nurses to provide care to these groups of people. The university hospitals have service administration different than hospitals under the regulation of MoPH. In this study, researchers classified hospitals into 3 clusters: community hospitals, advanced and standard hospitals, and university hospitals.
Continuing mental health service use and measurement
Continuing mental health service use in this study refers to continuing visits to the mental health clinic as the treatment plan or appointment attendance at mental health care service of older persons within six months after diagnosing the depressive disorders. Mental health service use was measured in two ways: frequency of mental health care visits and continuity of mental health services use. Firstly, the frequency of mental health care visits refers to the number of attendances at the mental health clinic of older persons within six months since the diagnosis date, excluding the first diagnosis date. Second, continuity of mental health services use refers to attending a mental healthcare appointment for older persons within six months after being diagnosed with depressive disorders. The respondence is categorized into non-continuing service use (score=0) and continuing service use (score=1). "Non-continuing service use" means that the older persons have a period of non-attending mental health service of 90 days or more since the diagnosis date. "Continuing service use" means that older persons attend mental health clinics continuously according to clinical appointments and never miss a clinical visit for depression treatment for more than 90 days.
Individual variables and measurement
Individual data were obtained forthe Thai older persons aged 60 and over from the starting date of this study and first or recurrent diagnosed with depressive disorders based on the 10th revision of the International Classification of Diseases (ICD-10) (F 32, F33, F34.1, F38, and F39) [33] since at least six months to one year before collecting data. The data were retrieved from electronic medical records of all hospitals providing care for depression to patients in Thailand. They had health insurance cards eligible for the same service and have lived in the community for at least six months. They were able to comprehend information in Thai, cooperate in the study, communicate by completing the Mini-cog Test on three or more occasions, and be contacted by phone or address to make appointments for study participation.Participants were excluded from this study if they had been diagnosed with mania or bipolar conditions,had severe somatic disease, could not answer questionnaires, or had severe depression and suicidal thoughts.
Individual demographic and clinical variables were obtained from medical records, including age (60-69; 70-79; ≥80 years), sex (male; female), marital status (married; others), comorbidity, and severity of depression. Comorbidity was measured using the Charlson Comorbidity Index (CCI) [34], a measure of the incidence of 23 common diseases. The possible total scores ranged from 0 to 42. The higher the score, the more severe burden of comorbidity and the greater the average yearly cost per patient. The severity of depression was classified into four diagnostic groups based on the criteria of the ICD-10 [33]: mild depressive symptoms (F32.0 and F33.0); moderate depressive symptoms (F32.1 and F34.1); severe depressive symptoms (F32.2 and F32.3), and unspecified or depression not otherwise specified (NOS) (F32.9, F38, and F39). Perceived sufficient income was assessed by asking about the perceived adequacy of the money earned from a person, company, or government over a period for daily living or a particular purpose (sufficient income; insufficient income). Attitude toward depression and its treatment (ATDS) and social support were assessed by interviewing older persons diagnosed with depressive disorders via standard questionnaires. ATDS was measured by attitude toward depression and a depression treatment scale [35]. The original ATDS consisted of a 27-item questionnaire with a Likert scale of 1 (strongly disagree) to 5 (strongly agree). In this study, the researchers translated the ATDS into Thai (ATDS-T) following WHO's tool translation instrument in all respects [36]. The ATDS-T utilized 25 items from the original 27-item ATDS scale with qualified content validity and reliability. The reliability of the ATDS-T was .70 (n=30). Perceived social support was measured using the Multidimensional Scale of Perceived Social Support (MSPSS) [37] and translated into Thai by Wongpakaran Tinakon and Wongpakaran Nahathai [38]. The MSPSS-Thai version consists of 12-items with a Likert scale of 1 (very strongly disagree) to 7 (very strongly agree) and overall positive opinions. The measurement consists of 3 sources of support, including family support, friend support, and significant-other support.
Organizational variables and measurement
Organizational characteristics deliver the mental health services relevant to patient care for depression. Administrative information of the 12 hospitals were obtained by interviewing a nurse of a mental health clinic or mental health outpatient clinic that had experienced care provision at an outpatient unit for at least five years or had experience caring for psychiatric patients for at least two years. The researchers developed an interview questionnaire for collecting information about organizational characteristics. The questionnaire was content validated by three experts in mental health services.Organizational attributes in this study consisted of hospital-level, nurse competency, nurse-patient ratio, and use of appointment reminders. Hospital-level was categorized according to mental health care resources in Thailand (university hospitals, advanced and standard hospitals, and community hospitals) [32,39]. A university hospital refers to a health care facility where the institute is under the university's authority. This health care facility combines health services with medical students' education and medical research. A university hospital provides health services to patients with highly specialized staff, technical equipment, and complete mental health teams. Advanced and standard hospital refers to the hospital under the MoPH. This kind of hospital is a high-referral-level hospital with highly specialized staff and technical equipment. Besides providing general health services, the hospital offers mental health services to patients with multidisciplinary psychiatric teams, outpatient psychiatry clinics, or inpatient departments. A community hospital refers to a health care facility under the MoPH. It is comfortable for people to access this hospital. Community hospitals consist of first-referral level and mid-referral hospitals. There is often only one general practice physician at this hospital. Patients are usually sent to a referral hospital if they need more complicated care within a service network. The community hospitals provide services by networking hospital care, called a Contracting Unit for Primary Care (CUP), and its' network. Nurse competency refers to the complex integration of knowledge, including professional judgment, skills, values, and attitudes based on the holism perspective [40].
This study's integrated nursing competency is ensured through formal nursing graduation and training in nursing specialty programs. These programs have curriculum goals focused on developing nursing competency at three different levels of education and training available in Thailand. The first group consists of 1) registered nurses (RN), 2) RN+ with a specialty in psychiatric and mental health nursing (PMHN), and a specialty in gerontological nursing (GERO-N). The second group consists of those with 1) RN, 2) RN + PMHN/GERO-N, and 3) RN + master's degree of nursing science (MNS). The last group consists of 1) RN, 2) RN+PMHN/GERO-N, 3) RN+MNS, and 4) RN+ an advanced practitioner nurse (APN). The nurse-patient ratio refers to the number of patients with mental illness/problems who received mental services in the outpatient department of the hospitals per day divided by the total number of nursing staff on duty providing care to those patients on that day. Appointment reminders are defined as strategies of reminders on the date of appointment attendance in mental health clinics (non-reminder; reminder before the appointment date by phone or text message).
Data collection
The data collection procedure included: firstly, extracting data of older persons with depressive disorders: the researchers, assistant researchers, and medical technology officers retrieved patient data from the hospital database (medical history, address, and phone number). Second, the researchers reviewed the medical records to gather several patients who met the inclusion criteria. Thirdly, 1,584 eligible patients were identified. Subsequently, co-researchers enlisted contactable patients to participate with 526 cases or 33.2% (526 of 1584) of eligible patients. Seventy-five contactable patients, or 14.3% (75 of 526), could not participate due to illness or their caregiver was not comfortable providing information. Finally, 85.7% (451 of 526) were willing to participate in this study. Various data collection methods were considered for maximum data acquisition based on the availability and convenience of participants and the health care settings. Data collection included 188 cases or 41.7% with a telephone interview, 152 cases or 33.7% with home visits, 47 patients or 10.4% responses by mail, and 64 cases or 14.2% face-to-face interviews at the hospital. Data completeness was verified after finishing the process of collection. Because 17 cases or 3.8% (17 of 451) had been diagnosed within two years, and 12 cases or 2.7% (12 of 451) were referred to health care services near their homes, 29 patients or 6.0% (29 of 451) were eliminated. Thus, finally, participants were 424 cases, or 94.0% (424 of 451). Nevertheless, the number of participants had remained representative of the population studied, as seen in Table 1.
Ethics
This study was reviewed and approved by the institutional review board of the Research Ethics Committee of the Faculty of Medicine, Siriraj hospital (COA No. Si527/2019), Medicine Ramathibodi Hospital, Mahidol University (COA No. MURA2019/1264), and the Committees of all selected hospitals under the Ministry of Public Health. Permission participants were provided with information and written informed consent as well. All procedures were performed following ethical guidelines and regulations. The data collection period started in May 2018 and went to November 2020.
Statistical analysis
Data management methods validated data entry by analyzing missing data, outliners, frequencies, means, standard deviations, and ranges of scores on each variable. Descriptive statistics were used to analyze categorical and continuous data. Categorical data included sex, marital status, sufficient income, the severity of depression, mental health service delivery system (hospital level, nurse competency, nurse-patient ratio, appointment reminder), mental health service use, and the continuity of care reported as frequency and percentage. Continuous data such as age, comorbidity, attitude toward depression, and social support were reported as mean and standard deviation (SD) or median, and range as appropriate. Latent class analysis (LCA) identified mental health service delivery systems based on contextual factors (hospital level, nurse competency, nurse-patient ratio, and appointment reminder). Four indices were used to select the correct number of latent classes, i.e., Bayesian information criterion (BIC), Akaike information criterion (AIC),Pearson's chi-square goodness of fit (χ2), and Likelihood ratio/deviance statistic (G2). Lower BIC, AIC, χ2, and G2 values indicate a better model fit. However, BIC for LCA models is a good indicator for class enumeration over the rest [41]. Description for each group was agreed upon through discussion with the research team. A marginal logistic regression model using a generalized estimating equation (GEE) for within-subject correlation between patient outcomes within the same hospital was performed for associating groups of mental health service delivery systems and individual characteristics with mental health service use.