Development and psychometric testing of the Family Functioning Questionnaire in Rehabilitation (FFQR)

Background/aim The present study aimed to develop a reliable and valid assessment tool for measuring family functioning in rehabilitation. Materials and methods Semistructured interviews were performed with 100 rehabilitation professionals working in pediatrics to identify the feature to be measured. The items determined with the qualitative analysis of the data were presented to 14 experts and content validity was provided. The questionnaire created based on the judgments of the experts was administered to 440 parents of children with special needs. Results After validity and reliability analysis, the final version of the questionnaire comprised 48 items with four factors identified as awareness, attitude and behavior, social participation, and engagement in rehabilitation. These factors explained 49.94% of the total variance and the factor loadings ranged from 0.492 to 0.773. Internal consistency reliability calculated with the Cronbach alpha coefficient was found to be 0.943. The test-retest reliability coefficient between the two administrations with a two-week interval was found as 0.772. Conclusion The findings of the study showed that the newly developed Family Functioning Questionnaire in Rehabilitation met the criteria for examining the role of families of children with special needs in rehabilitation programs and had adequate psychometric properties.

recognize the child as a family member and acknowledge the influence of other family members [7][8][9].
In the International Classification of Functioning, Disability, and Health (ICF), developed by the World Health Organization for providing comprehensive information on health and health-related issues, it is emphasized that assessments for rehabilitation interventions should have a holistic view that takes into account the relationship of the individual and the individual's sociocultural environment. According to the ICF, functioning is a part of the ongoing dynamic developmental process through interaction with the family [10]. To be able to identify the factors that can affect the individual and the rehabilitation process, the evaluation of the whole family is important [11]. Familycentered assessments aim to identify the strengths of the family and the child. Priorities, values, expectations, and the needs of the families are the focus of evaluation. In this process, family members have the opportunity to observe their attitudes towards their children [12].
Family support is important in ensuring the participation of children with special needs in school and community life. The family contributes to health and wellbeing by providing support and transportation, influencing the success of long-term rehabilitation, and enabling positive living in spite of the disability. For this reason, family-centered assessments should take into account the importance of the role of the family in rehabilitation [13,14]. Previous studies have presented some assessment tools for investigating physical, emotional, or psychological influences and the needs and social participation of parents after having a child with special needs [15][16][17][18]. In addition, there are commonly used generic measures assessing various aspects of family functioning such as the Impact on Family Scale [19], which measures parents' perception of the effects of the child's condition on family life, and the Family Environment Scale [20], which is used to assess the family environment from different perspectives within the family. However, to the best of our knowledge, there is a need for an objective, valid, and reliable tool that can measure the extent to which the family contributes to rehabilitation. Therefore, the objectives of the present study were to develop an assessment tool that measures family functioning in rehabilitation and to establish its psychometric properties.

Study design
In the present study, a questionnaire which is specific to Turkish society was developed for the families of children with special needs. The study protocol was performed following the ethical codes of the World Medical Association (Declaration of Helsinki) and was approved by the Hacettepe University Noninterventional Clinical Research Ethics Board (Approval no: GO 14/416, Date: 05.11.2014). All participants provided written informed consent. This study was designed with an exploratory sequential mixed methods approach integrating qualitative and quantitative research and data. The mixed methods research design is particularly useful when developing and testing an instrument if there is no available measure or the existing ones poorly represent the phenomenon [21].

Participants
Three different sample groups were included in the present study. To determine the feature to be measured the first sample included 100 rehabilitation professionals working in the field of pediatrics, including physiotherapists, psychologists, child development specialists, special education teachers, occupational therapists, a social worker, and a physician. Secondly, to review and confirm the content validity of the draft questionnaire a team of experts consisting of fourteen academicians with expertise in health sciences was consulted. Finally, the third sample comprised 440 parents of children with special needs who applied to the Hacettepe University Faculty of Health Sciences Department of Physical Therapy and Rehabilitation and Occupational Therapy in Ankara, Turkey. Inclusion criteria for parents were to have a child with special needs between the ages of 1 and 18 years, to continue a rehabilitation program for at least one year, and to participate voluntarily after being informed verbally and in writing about the research. Exclusion criteria were not being able to establish communication and cooperation and not being a primary caregiver of a child with special needs.

Phase 1: Item generation
A literature review and semistructured interviews were used to develop the items of the Family Functioning Questionnaire in Rehabilitation (FFQR). The literature was reviewed to identify the role of the family in rehabilitation and related domains. After the literature review, 5 initial domains were determined for the interviews: environment (home, school environment, rehabilitation centers, other family members living at home, relatives, acquaintances, friends, physical and social environment), time (the time spent for children, such as treatment sessions), communication (communication with health professionals, children with special needs, other people), support (socioeconomic level, educational activities, security, social participation), and other issues. The initial items of the FFQR were generated by conducting semistructured interviews with 100 rehabilitation professionals. Data obtained from the interviews were recorded and analyzed through thematic analysis.

Phase 2: Expert views and content validity
As a result of the qualitative analysis of the obtained data, an item pool with 121 statements was created. Fourteen experts with sufficient knowledge and experience in the rehabilitation of children with special needs evaluated the appropriateness of the draft scale. Expert assessments included views on whether the items represented the feature to be measured, whether it was expressed simply and clearly, and whether it would be understood by the target group. With the feedback received from the experts, the comprehensibility, usefulness, and suitability of the items were reviewed and necessary adjustments were made.
In addition to the qualitative content validity method, the content validity ratio (CVR) was used to make the expert opinions digitized and statistically interpretable. For this purpose, experts were asked to rate each item using a three-point ordinal scale (1: not necessary, 2: useful but not essential, 3: essential). The CVR was developed by Lawshe [20] as a statistical value that reflects whether each item is included in the scale and its varies between 1 and -1. It is calculated with the following formula: CVR = (n e -N/2)/(N/2), in which n e is the number of experts indicating "essential" and n is the total number of experts. Once the CVR of each item is computed, the items with positive CVRs are compared with the minimum CVR, which is determined by the number of experts at a certain level of significance. Only the items meeting the minimum CVR value remain in the scale. In the present study, since the expert team was composed of 14 members, a minimum CVR of 0.51 was required at the 5% level of significance. After the retained items were identified, the content validity index (CVI), the mean of the CVR values of those items, was computed for the whole test [22].

Phase 3: Administration of the questionnaire
The initial version of the FFQR, consisting of 88 items, was administrated to 440 parents of children with special needs. Participants responded to each question using a fivepoint Likert scale ranging from 1, 'strongly disagree, ' to 5, 'strongly agree. ' In addition to the FFQR, a demographics form was used to gather typical demographic information about the children and their families (e.g., age, sex, diagnosis of the child).

Data analyses
An item analysis was performed to assess whether the individual items contributed to the total questionnaire. Item-to-total correlation coefficients and the reliability coefficients if item deleted were computed for item analysis.
Exploratory factor analysis (EFA) was used to evaluate the structural validity. Bartlett's test of sphericity and the Kaiser-Meyer-Olkin (KMO) test of sampling adequacy were calculated to determine the factorability of the data. After the data were found suitable for factor analysis, principal component analysis (PCA) with varimax rotation was used to examine the factor structure of the questionnaire. Factors with eigenvalues greater than 2 were considered significant.
Internal consistency and test-retest analyses were conducted for the reliability of the questionnaire. The Cronbach alpha coefficient was used to evaluate internal consistency. To confirm the test-retest reliability, the Pearson correlation coefficient was calculated between two administrations. SPSS 23.0 for Windows was used for statistical analyses and the significance level was defined as P < 0.05.

Results
In this study, which aimed to develop a questionnaire that measures family functioning in rehabilitation, a total of 100 rehabilitation professionals were interviewed to determine the feature to be measured. Table 1 provides the demographic data of the participants who took part in interviews (age, sex, profession, academic qualification, and years of experience).
After the expert views were obtained, the CVRs were calculated for each item and those with negative and zero  [23].
The 88-item draft scale was applied to 440 families of children with special needs. Participants consisted of 440 parents of children with a mean age of 7.9 ± 4.64 years (247 females, 193 males). The sample included 335 mothers and 105 fathers. The mean age was 36.12 ± 6.81 years for mothers and 39.74 ± 7.10 years for fathers. Demographic characteristics of the participants are given in Table 2.
The reliability coefficient (Cronbach's alpha) of the scale was obtained as 0.929 by applying item analysis to the 88-item scale. This value is quite high and shows consistency between the items in the scale. As a result of item analysis, it was seen that the reliability coefficient of the scale increased when items 26, 31, 32, 34, 37, 53, and 58 were excluded from the scale separately. Therefore, it was decided to remove these items from the scale. Since the item-total correlation of item 20 was less than 0.25, this item was also excluded from the scale. Thus, with item analysis, 8 items were removed from the scale and the 88-item scale was reduced to 80 items. The reliability coefficient of the 80-item scale increased from 0.929 to 0.958.
The scale, having been reduced to 80 items by item analysis, was examined in terms of a structure suitable for factor analysis. For this purpose, the KMO coefficient, which is a measure of sample adequacy for factor analysis, was used, and the determinant value of the correlation matrix was examined by Bartlett's test of sphericity, which showed whether the correlation matrix was equal to the identity matrix. The KMO value was obtained as 0.862 and Bartlett's sphericity test value was significant (c 2 = 25213.86, P < 0.001). These values showed that the sample met the criteria for factor analysis. In the initial EFA (PCA with varimax rotation), items having factor loadings greater than 0.45 were taken into account. The items that had factor loadings distributed in more than one factor with the difference between these loads being less than or equal to 0.10 were excluded from the analysis. After testing the 80 items, a total of 20 items were excluded from the scale, 19  the difference being less than 0.10. In the second round, the factor loadings of 11 items (2,7,9,13,19,30,33,35,46, 64, 69) were less than 0.45 and one item (item 80) had a difference of less than 0.10. In the final factor analysis, all of the remaining 48 items had factor loadings greater than 0.45, ranging from 0.49 to 0.77. The EFA confirmed a four-factor structure explaining 49% of the total variance. The items that loaded on the four factors were examined in terms of content and named as awareness (F1, 18 items), attitude and behavior (F2, 16 items), social participation (F3, 8 items), and engagement in rehabilitation (F4, 6 items). Table 3 provides English translations of the original Turkish items and their factor loadings. Two hundred subjects of the sample group were retested to determine the reliability after 2 weeks and the Pearson correlation coefficient between the two applications was found to be 0.772 (P = 0.001). The internal consistency coefficient was also used in the reliability analyses of the questionnaire. The Cronbach alpha of the subdomains ranged from 0.799 to 0.912, and the Cronbach alpha of the questionnaire was found to be 0.943. Consequently, the FFQR showed valid and reliable scores of family functioning within the rehabilitation context.

Discussion
In recent years, when studies about the rehabilitation programs of children with special needs are examined, the accepted approaches are intervention methods in which the therapists and the families cooperate, seeing the child and the family as a whole and determining the targets in this direction. For these children who spend the majority of their time with their families, the contribution of the family is important in ensuring that rehabilitation is effective, permanent, and adaptable to daily life [15,[24][25][26][27]. Family-centered research and practices, which emphasize the importance of the involvement of the family in the evaluation and intervention process in the rehabilitation of children with special needs, is gradually increasing. However, there is a lack of measuring the contribution of the family in this process.
When the literature is examined, it is seen that family participation in rehabilitation is particularly evaluated in goal-setting and decision-making processes [28][29][30], and qualitative research techniques such as the interview method are mostly used in these evaluations. It was found that the methods used are not structured and do not have standardization [31][32][33]. There is a need for a standardized, reliable, and valid measurement tool to determine the level of functioning. This study reports a comprehensive, selfreported measurement tool developed to measure family functioning in the rehabilitation programs of children with special needs: the Family Functioning Questionnaire in Rehabilitation (FFQR). The FFQR, which consists of four main domains, showed adequate psychometric properties of family functioning within the rehabilitation context. The needs and sociocultural characteristics of society play a role in structuring scales. Therefore, it is important to evaluate functioning with scales developed based on the experiences of individuals working in the relevant field. In the present study, after determining the need for measuring family functioning, the items of the questionnaire were created by interviewing rehabilitation professionals accordingly and these items were presented to experts in the field. Thus, it was assured that the questionnaire reflected family functioning better by considering the experiences of rehabilitation staff.
The FFQR is a new measurement tool available for healthcare researchers and practitioners.
The tool assesses the family function in four different dimensions and a separate score that can be calculated for each subdimension. It has a general content applicable to the families of children with special needs who have different diagnoses. With its large sample size, mixed-type design and good psychometric properties, this scale is an important value in family-centered research.
Although the current questionnaire fills an important gap in the field of rehabilitation with its comprehensiveness, there are still some limitations. First, the FFQR is a selfreported questionnaire and it may be difficult to predict the accuracy of the results due to the social desirability bias phenomenon. Second, during the development of the questionnaire, real-life conditions and the child and family's natural environments were not observed and the views of families were not included. Further studies are needed in which the results are supported by qualitative interview methods and family views are also evaluated. It is also suggested that a therapist version of the questionnaire be developed so that therapists working with children with special needs can evaluate the functioning of the family in rehabilitation.
In conclusion, the FFQR was developed as a questionnaire with sufficient validity and reliability that can be used in the rehabilitation field. It can be used in studies involving family training interventions and the inclusion of the family as a part of the rehabilitation process. With the FFQR, comparative studies examining factors such as age group, diagnosis, and severity of the disease and studies measuring the functioning level of families from different socioeconomic levels can be designed.

Acknowledgment/Disclaimers/Conflict of interest
The present study was funded by the Scientific and Technological Research Council of Turkey (TÜBİTAK) under the scope of the 2211/A Domestic PhD Scholarship Program.
This study was presented as a poster presentation at the 28th Annual Meeting of the European Academy of Childhood Disability (EACD), 1-4 July 2016, Stockholm, Sweden.
The authors declare that they have no conflict of interest.