Examination of validity, reliability, and interpretability of a self-reported questionnaire on Occupational Balance in Informal Caregivers (OBI-Care) – A Rasch analysis

Objectives Informal caregivers often experience a restriction in occupational balance. The self-reported questionnaire on Occupational Balance in Informal Caregivers (OBI-Care) is a measurement instrument to assess occupational balance in informal caregivers. Measurement properties of the German version of the OBI-Care had previously been assessed in parents of preterm infants exclusively. Thus, the aim of this study was to examine the measurement properties of the questionnaire in a mixed population of informal caregivers. Methods A psychometric study was conducted, applying a multicenter cross-sectional design. Measurement properties (construct validity, internal consistency, and interpretability) of each subscale of the German version of the OBI-Care were examined. Construct validity was explored by assessing dimensionality, item fit and overall fit to the Rasch model, and threshold ordering. Internal consistency was examined with inter-item correlations, item-total correlations, Cronbach’s alpha, and person separation index. Interpretability was assessed by inspecting floor and ceiling effects. Results A total of 196 informal caregivers, 171 (87.2%) female and 25 (12.8%) male participated in this study. Mean age of participants was 52.27 (±12.6) years. Subscale 1 was multidimensional, subscale 2 and subscale 3 were unidimensional. All items demonstrated item fit and overall fit to the Rasch model and displayed ordered thresholds. Cronbach’s Alpha and person separation index values were excellent for each subscale. There was no evidence of ceiling or floor effects. Conclusions We identified satisfying construct validity, internal consistency, and interpretability. Thus, the findings of this study support the application of the German version of the OBI-Care to assess occupational balance in informal caregivers.

Rasch analysis of the Brain Injury Screening Tool (BIST) in mild traumatic brain injury

Objective To evaluate the psychometric properties of the Brain Injury Screening Tool (BIST) symptom scale in a sample of people with a mild Traumatic Brain Injury (mTBI) through Rasch analysis, and to obtain an interval level measurement score for potential clinical use. Materials and methods Data were obtained from 114 adults aged over 16 years, who had experienced at least one mTBI in the past 10 years. Participants were recruited via social media, concussion clinics and sports organisations over a 4-month period between May and September 2020. Participants were asked to compete the symptom scale of the BIST tool via an anonymous online questionnaire. Internal construct validity, dimensionality, person separation index, and differential item functioning of the BIST were examined with Rasch analysis. Results BIST in its original form produced a satisfactory item-trait interaction, and good reliability, but was found to be multi-dimensional. Rasch analysis of the full scale with three domains as subtests resulted in acceptable model fit (χ2(6) =3.8, p > 0.05), with good reliability (Person Separation Index = 0.84), and uni-dimensionality. Differential Item Functioning (DIF) analysis displayed no significant DIF effects for sex or age revealing that people responded consistently and similarly to the individual BIST items based on severity of symptom burden. Conclusions The 15-item symptom scale of the BIST tool is a psychometrically sound measure of symptom burden following mTBI. The findings provide support for use of both total and sub scale scores for clinical use. Ordinal to interval score conversions are recommended for use when using the scores for research purposes in mTBI.

Psychometric Properties of the CASP-12 Scale in Portugal: An Analysis Using SHARE Data

The purpose of this study is to assess the psychometric properties of the Portuguese version of the Control, Autonomy, Self-realization, and Pleasure (CASP)-12 scale used in the Survey of Health, Aging and Retirement in Europe (SHARE) project. Data were obtained from a representative sample of 1666 people aged ≥50 years living in Portugal and participating in the SHARE wave 6. In addition to the CASP-12 scale, sociodemographic data and health status, activity limitation (GALI), depression (Euro-D) and satisfaction with life scores were collected. Data quality and acceptability, construct and structural validity and internal consistency of the CASP-12 scale were analyzed. A Rasch analysis was also performed. CASP-12 total score (mean: 33.3; standard deviation: 5.8, range: 12–48) correlated with Euro-D (−0.57) and with life satisfaction (0.52). Mean scores were significantly lower for women, people aged ≥75 years and those with activity limitations and worse health status (p < 0.001). The confirmatory factor analysis showed good fit to the 4-factor model (root mean squared error of approximation (RMSEA): 0.07; comparative fit index (CFI): 0.90, χ2 (48) = 444.59, p < 0.001), which was confirmed by Rasch analysis (χ2 (36) = 10.089, p = 0.745, person separation index (PSI) = 0.722 for the 4-factor model). For domains, person separation index ranged 0.31–0.79 and Cronbach’s alpha, 0.37–0.73. In conclusion, the Portuguese version of the CASP-12 scale presents some inadequacies in acceptability, internal consistency and structural validity.

Validation of the patient activation measure in patients at discharge from hospitals and at distance from hospital care in Sweden

Background The Patient Activation Measure (PAM) is a recognized measure of how active patients are in their care, and has been translated into several languages and cultural contexts. Patient activity, self-care, and health literacy have become increasingly important aspects of health care, and thus reliable measures of these are needed. However, a Swedish translation of PAM is currently lacking. The aim of the study was to translate and assess the validity and reliability of the Swedish PAM-13. Methods A self-report questionnaire was handed out to 521 patients at ten medical, geriatric, and surgical wards, and one Virtual Health Room. The Rasch model was employed, using the partial credit model, to assess the functioning of the PAM scale, item fit, targeting, unidimensionality, local independence, differential item functioning (DIF), and person-separation index. Evidence of substantive, content, structural, and external validity was examined. Results Of the 521 patients who were consecutively handed a questionnaire, 248 consented to participate, yielding a response rate of 47.6%. The average measure for each category advanced monotonically. The difficulty of the PAM items ranged from − 1.55 to 1.26. The infit and outfit values for the individual items were acceptable. Items 1, 2, and 4 showed disordered thresholds. The mean person location was 1.48 (SD = 1.66). The person-item map revealed that there were no item representations at the top of the scale. The evidence for unidimensionality was ambiguous and response dependency was seen in some items. DIF was found for age. The person separation index was 0.85. Conclusion The Swedish PAM-13 was reliable, but was not conclusively found to represent one underlying construct. It seems that the Swedish PAM-13 lacks strong evidence for substantive, content, and structural validity. Although valid and reliable measures of ability for activation in self-care among patients are highly warranted, we recommend further development of PAM-13 before application in everyday clinical care.

Improving Measurement of Trait Competitiveness: A Rasch Analysis of the Revised Competitiveness Index With Samples From New Zealand and US University Students

Measuring competitiveness is necessary to fully understand variables affecting student learning. The 14-item Revised Competitiveness Index has become a widely used measure to assess trait competitiveness. The current study reports on a Rasch analysis to investigate the psychometric properties of the Revised Competitiveness Index and to improve its precision for international comparisons. Students were recruited from medical studies at a university in New Zealand, undergraduate health sciences courses at another New Zealand university, and a psychology undergraduate class at a university in the United States. Rasch model estimate parameters were affected by local dependency and item misfit. Best fit to the Rasch model (χ2(20) = 15.86, p = .73, person separation index = .95) was obtained for the Enjoyment of Competition subscale after combining locally dependent items into a subtest and discarding the highly misfitting Item 9. The only modifications required to obtain a suitable fit (χ2(25) = 25.81, p = .42, person separation index = .77) for the Contentiousness subscale were a subtest to combine two locally dependent items and splitting this subtest by country to deal with differential item functioning. The results support reliability and internal construct validity of the modified Revised Competitiveness Index. Precision of the measure may be enhanced using the ordinal-to-interval conversion algorithms presented here, allowing the use of parametric statistics without breaking fundamental statistical assumptions.