2.1. Study Design
This study is reported in line with the STROBE statement [a]. This is a cross-sectional study carried out using face-to-face quantitative structured interviews based on standardized questionnaires.
2.2. Participants and setting
The target population of this study was made up of informal caregivers of dependent people (assessed by health care professionals using the Barthel Index) in at least one of the self-care categories and who were discharged from the medical units at a Portuguese urban hospital to their home. The selection of caregivers was carried out by health care professionals.
Caregiver´s interviews where performed by nurses and nursing students who did not work at the unit to prevent influencing patients’ answers, following a standardised protocol.
All the interviews were carried out at the hospital at the moment of discharge home.
Participants were given information about the study and that they were free to withdraw from the study at any time for any reason, and with no obligation to give the reason for withdrawal.
The names and any other identifying details of participants were not collected in any of the surveys.
Data collection occurred from February to June 2017. In this period 900 patients were discharged from hospital, but only 324 filled in the eligibility criteria for this study. From those, 143 informal caregivers accepted to participate, representing 44,1% of caregivers of dependent people discharged home.
2.3. Measures
The interview conducted consisted of two parts:
(a) Socio-demographic and family data, experience of the caregiver,
(b) Caregiver's skills specifically relating to care, professional information receive which provided them with information.
The items used to assess the caregiver's skills in caring for a dependent person were built based on four criteria: a) the items of other instruments, b) meetings with health care professionals, c) meetings with informal caregivers, d) bibliographical research.
Given these criteria, the first version of the instrument was made up of 114 items spread over 9 domains corresponding to the areas of skills. These items have been subject to evaluation by a panel of experts using the Delphi Method. Each of these items was rated on 5 response options: Strongly Disagree; Disagree; Agree; Strongly Agree and Not applicable. For each of the areas and respective items, the informal caregiver was asked about the degree of dependence of their family member using a close-ended question with three response options: Independent, partially dependent and totally dependent.
For this study it was pretended to access the perception of informal caregivers on the dependency of their family member. For this reason, and considering that the Barthel Index, designed to health care professionals, could not address all the issues of dependency that worries the caregivers, we decided on create a new instrument. By using the items that caregivers referred to be relevant for their caring role, together with specific items pointed out by health care professionals, the instrument at its final version, covers different and specific areas, and it is broader than the existing instruments to measure Activities Daily Living (ADL) and Instrumental Activities of Daily living (IADL).
After determining the internal consistency of each of the domains, the scale was composed of 101 items according to the data in table 1. The 13 deleted items were based on two criteria: alpha of each indicator was not higher than the global alpha of their respective domains, and the results of the correlation of each item with the global rating (by removing the respective item) were not higher than 0.20. An Exploratory factor analysis was conducted and described in the analysis.
It should be noted that all of the domains have good reliability, with the exception of communication domain which presents a Cronbach’s Alpha score lower than recommended (<0.60). However we have not excluded it due to its value in this area of caregivers' skills.
Table 1 - Number of items in each subscale and Cronbach's alpha value of each subscale
|
Nº items before validation
|
Nº end items
|
Cronbach's alpha
|
Feeding
|
24
|
19
|
0.905
|
Sanitary hygiene
|
13
|
10
|
0.787
|
Comfort
|
14
|
12
|
0.904
|
Mobility
|
12
|
12
|
0.835
|
Transfer
|
10
|
10
|
0.859
|
Dressing and undressing
|
7
|
6
|
0.685
|
Medication
|
12
|
10
|
0.808
|
Management of symptoms
|
17
|
17
|
0.911
|
Communication
|
5
|
5
|
0.544
|
Total items
|
114
|
101
|
|
2.4 Ethical approval
The study protocol, the participant informed consent documentation were submitted to the Central Hospital of Leiria Ethics Committee (04 - 2017/05/02), who approved the study.
An appropriate location for data collection was always ensured, and the norms in use the Declaration of Helsinki (2014) were met.
2.5 Analysis
Descriptive and inferential statistics were used. Taking into account the size of the sample, subsamples and very different sample sizes, non-parametric statistical techniques were used, namely the Mann-Whitney test, Spearman’s correlation according to the type of variables under study.
The reliability of the 9 domains was measured by calculating internal consistency (Cronbach’s alpha), and individual item analysis was performed by calculating the corrected item-total correlations and α if the item was removed.
In this study means of Cronbach’s α >0.6 are considered acceptable, α >0.7 considered good, α >0.8 very good and α >0.9 are considered excellent.
Exploratory factor analysis was conducted with the 101items. Using Varimax rotation, and Kaiser’s eigenvalues greater than one, a nine factor structure was extracted, explaining 61.039% of the variance. All the items correlated at least 0.3 with at least one other item, non-inclusion of items that scored in more than one factor less than 0,10 and not considering each factor with less than three items, suggested reasonable factorability. The Kaiser-Meyer-Olkin measure of 0.745, above the recommended value of 0.6 was considered good, and Bartlett’s test of sphericity (16171.631; p=0.000) indicated good fit of the structure. The diagonals of the antiimage correlation matrix were also all over 0.5 Finally, the communalities were all above 0.392 and below 0.817, further confirming that each item shared some common variance with other items. Given these overall indicators, factor analysis was deemed to be suitable.
It should be noted that all of the domains have good reliability, with the exception of communication domain which presents a Cronbach’s Alpha score lower than recommended (<.60)