Construct Validity of the SF-12v2 for the Homeless Population with Mental Illness: An Instrument to Measure Self-Reported Mental and Physical Health

Impact of chronic illness caused by chikungunya fever on quality of life and functionality

BACKGROUND

Chikungunya fever compromises the functionality and quality of life in the affected individuals, even one year after the acute phase of the disease. Chronically affected people experience direct impairment in performing daily activities, along with a risk of developing other morbidities.

BACKGROUND

◼ Even after a year, chikungunya fever-affected people experience damage to their physical and mental health.

BACKGROUND

◼ Positive screening for depression risk was 13.5 times more likely in chronically affected.

BACKGROUND

◼ Patients with chronic chikungunya fever had a 76 times higher risk of walking impairments.

OBJECTIVE

To evaluate the impact of chronic illness caused by chikungunya fever on the quality of life and functionality of affected individuals.

METHODS

A cross-sectional and comparative study was conducted in which two groups were investigated: a Chikungunya Group comprising 25 patients with chronic fever screened after 1 year of illness via a telephonic survey, and a Healthy Group comprising 25 healthy individuals matched for sex and age by face-to-face interview. The Stanford HAQ 20-Item Disability Scale (HAQ) and the Short Form Health Survey (SF-12) questionnaires were administered to both groups. Generalized Linear Models, Pearson χ2 tests, and odds ratios were used to evaluate the test results.

RESULTS

Significant differences in functional capacity and quality of life were observed between the Chikungunya and Healthy Groups. The chance of some impairment in functionality was also much higher in the Chikungunya Group in four of the HAQ categories, especially in the "walking" category (adjusted OR= 109.40). Further, the Chikungunya Group had a higher chance of presenting a below-average score in the mental component summary of the SF-12 (adjusted OR= 16.20) and of being positive in depression risk screening (adjusted OR= 34.57).

CONCLUSION

Even one year after the acute phase, chikungunya fever can compromise the functionality and quality of life in affected individuals, with direct impairment in performing daily activities. Studies and therapeutic plans for chikungunya fever should consider the long-term impacts of this disease.

Mental health disparities across sexual orientations during the COVID-19 pandemic: Longitudinal analysis of a UK nationally representative cohort

OBJECTIVES

During COVID-19, sexual minority groups may have experienced heightened mental health challenges, amplified by unique stressors and the effects of pandemic-related restrictions. This study investigates the differential impact of the pandemic on mental health across sexual orientations, leveraging population-representative data to explore these disparities.

STUDY DESIGN

Prospective cohort design.

METHODS

Data from the United Kingdom Household Longitudinal Study (waves 8-12) was used. Monthly COVID-19 incidence rates at the regional level were used to indicate pandemic severity. Mental health outcomes were evaluated using the Mental Component Score of the Short Form-12 (MCS-12) survey. To examine whether COVID-19 led to differential impacts across sexual orientation, fixed-effect longitudinal models were employed, controlling for individual and time-variant covariates.

RESULTS

Lesbian women experienced a significant mental health decline during the COVID-19 pandemic, with a 3.10 MCS-12 score decrease (95 % confidence interval (CI): -5.77 to -0.43) and an 11.0 % higher likelihood of depression (95%CI: -0.3 % to 22.3 %, p = 0.057) compared to heterosexual women. Conversely, the impact on the mental health of heterosexual women was negative but not significant (-0.22; 95%CI: -0.47 to -0.04). Bisexual individuals and other women showed non-significant mental health declines. For men, COVID-19's effect on heterosexuals was similarly non-significant (-0.21; 95%CI: -0.48 to 0.1), with no significant differences observed in gay, bisexual, and other men.

CONCLUSIONS

Sexual minority individuals, especially lesbian women, faced heightened mental health challenges during COVID-19, emphasizing the urgency for targeted interventions.

Long-term trends in mental health disparities across sexual orientations in the UK: a longitudinal analysis (2010-2021)

BACKGROUNDS

In the context of increasing hate crimes, legislative challenges, and anti-LGBTQ + sentiment, we conducted the first study that comprehensively examined long-term mental health disparities across sexual orientations in the UK from 2010 to 2021. Prior studies predominantly relied on cross-sectional or limited longitudinal designs, thus failing to capture evolving trends over a decade and providing crucial insights into the dynamics of mental health challenges faced by sexual minorities, essential for devising targeted public health interventions and policies.

METHODS

Waves 2-12 of the UK Longitudinal Household Survey for adults (n = 52,591) were used. MCS-12 (Mental Health Component Scale of the Short-Form Health Survey) for mental functioning and GHQ (General Health Questionnaire) for psychological distress were included as the main outcomes, along with other measures of well-being. Mixed-effect longitudinal models were used to examine the trends of mental health disparities across sexual orientations.

RESULTS

Relative to their heterosexual counterparts, psychological distress (GHQ) increased for gay men, lesbians, and women with "other" orientations. Bisexual women saw the steepest increase from 1.69 higher GHQ vs. their heterosexual counterparts in 2010 (95%CI: 0.81 to 2.57), up to 3.37 in 2021 (95%CI: 2.28 to 4.45). Similar trends were also shown in the other measures.

CONCLUSIONS

The study highlights increases in mental health disparities between sexual minorities and heterosexuals. The escalating psychological distress among sexual minorities, particularly bisexual women, calls for an urgent, multi-faceted, and intersectoral response. This approach must address both symptoms and the social structures perpetuating these disparities across sexual orientations.

Validation of an Adapted Version of the Veterans RAND 12-Item Health Survey for Older Adults Living in Long-Term Care Homes

BACKGROUND AND OBJECTIVES

The Veterans RAND 12-Item Health Survey (VR-12) is a generic patient-reported outcome measure of physical and mental health status. An adapted version of the VR-12 was developed for use with older adults living in long-term residential care (LTRC) homes in Canada: VR-12 (LTRC-C). This study aimed to evaluate the psychometric validity of the VR-12 (LTRC-C).

RESEARCH DESIGN AND METHODS

Data for this validation study were collected via in-person interviews for a province-wide survey of adults living in LTRC homes across British Columbia (N = 8,657). Three analyses were conducted to evaluate validity and reliability: (1) confirmatory factor analyses were conducted to validate the measurement structure; (2) correlations with measures of depression, social engagement, and daily activities were examined to evaluate convergent and discriminant validity; and (3) Cronbach's alpha (r) statistics were obtained to evaluate internal consistency reliability.

RESULTS

A measurement model with 2 correlated latent factors (representing physical health and mental health), 4 cross-loadings, and 4 correlated items resulted in an acceptable fit (root-mean-square error of approximation = 0.07; comparative fit index = 0.98). Physical and mental health were correlated in expected directions with measures of depression, social engagement, and daily activities, though the magnitudes of the correlations were quite small. Internal consistency reliability was acceptable for physical and mental health (r > 0.70).

DISCUSSION AND IMPLICATIONS

This study supports the use of the VR-12 (LTRC-C) to measure perceived physical and mental health among older adults living in LTRC homes.

Rasch analysis of the beck depression inventory in a homeless and precariously housed sample

The approach to analysis of and interpretation of findings from the Beck Depression Inventory (BDI), a self-report questionnaire, depends on sample characteristics. To extend work using conventional BDI scoring, the BDI's suitability in assessing symptom severity in a homeless and precariously housed sample was examined using Rasch analysis. Participants (n=478) recruited from an impoverished neighbourhood in Vancouver, Canada, completed the BDI. Rasch analysis using the partial credit model was done, and the structural validity, unidimensionality, and reliability of the BDI were studied. A receiver operating characteristic curve determined a Rasch cut-off score consistent with clinical depression, and Rasch scores were correlated with raw scores. Good fit to the Rasch model was observed after rescoring all items and removing Item 19 (Weight Loss), and unidimensionality and reliability were satisfactory. Item 9 (Suicidal Wishes) represented the most severe symptom. Rasch-based scores detected clinical depression with moderate sensitivity and specificity, and were positively correlated with conventional scores. The BDI in a community-based sample of homeless and precariously housed adults satisfied Rasch model expectations in a 20-item format, and is suitable for assessing symptom severity. Future research on depression in similar samples may reveal more information on using specific symptoms to determine clinical significance.

Psychometric properties of kidney disease quality of life-36 (KDQOL-36) in dialysis patients in Indonesia

OBJECTIVE

The study aimed to evaluate the psychometric properties of KDQOL-36 Bahasa Indonesia in hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients in Indonesia.

METHODS

The psychometric analysis was conducted in three hospitals offering both HD and CAPD. The validity was assessed through structural, convergent, and known-group validity, while reliability was evaluated using internal consistency and test-retest reliability.

RESULTS

The study involved 370 participants of which 71% received HD treatment. No floor and ceiling effects (< 10%) were identified. Confirmatory factor analysis supported a good model fit for both generic and kidney-specific domains, while exploratory factor analysis revealed three factors for kidney-specific domains and only three items with a loading factor below 0.4. Convergent validity showed positive correlations between kidney-specific domains, generic domains, and EQ-5D. The comparison of quality of life among subgroups based on dialysis type and whether or not patients had diabetes supported the hypotheses of known-group validity. Cronbach's alpha and omega values had demonstrated good internal consistency. Test-retest reliability indicated burden of kidney disease had good reliability, while other domains had moderate reliability.

CONCLUSION

The study supports the validity and reliability of both generic and kidney-specific domains of KDQOL-36 Bahasa Indonesia to evaluate quality of life in patients with HD and CAPD in Indonesia. As health-related quality of life is a crucial predictor of patient outcomes, this report contributes new evidence about validity and reliability to recommend the use of KDQOL-36 Bahasa Indonesia in dialysis centers.

The impact of novel and traditional food bank approaches on food insecurity: a longitudinal study in Ottawa, Canada

Background

Food insecurity is strongly associated with poor mental and physical health, especially with chronic diseases. Food banks have become the primary long-term solution to addressing food insecurity. Traditionally, food banks provide assistance in the form of pre-packed hampers based on the food supplies on hand, such that the food items often do not meet the recipients’ cultural, religious or medical requirements. Recently, new approaches have been implemented by food banks, including choice models of food selection, additional onsite programming, and integrating food banks within Community Resource Centres.

Methods

This study examined changes in food security and physical and mental health, at four time points over 18 months at eleven food banks in Ottawa, Ontario, Canada. The participants – people who accessed these food banks – were surveyed using the Household Food Security Survey Module (HFSSM) and the Short-Form Health Survey Version 2 (SF-12). Statistical analyses included: pairwise paired t-tests between the mean perceived physical and mental health scores across the four waves of data collection, and longitudinal mixed effects regression models to understand how food security changed over time.

Results

The majority of people who were food insecure at baseline remained food insecure at the 18-month follow-up, although there was a small downward trend in the proportion of people in the severely food insecure category. Conversely, there was a small but significant increase in the mean perceived mental health score at the 18-month follow-up compared to baseline. We found significant reductions in food insecurity for people who accessed food banks that offered a Choice model of food distribution and food banks that were integrated within Community Resource Centres.

Conclusions

Food banks offer some relief of food insecurity but they don’t eliminate the problem. In this study, reductions in food insecurity were associated with food banks that offered a Choice model and those that were integrated within a Community Resource Centre. There was a slight improvement in perceived mental health at the 18-month time point; however, moderately and severely food insecure participants still had much lower perceived mental health than the general population.

Self-Rated Mental and Physical Health of U.S. Gulf Coast Residents

Repeated exposure to hurricanes and tropical storms likely impacts the mental and physical health of populations living along the U.S. Gulf Coast. In this study, the self-rated physical and mental health of residents in the U.S. Gulf Coast was estimated and factors associated with differences in self-rated health were identified. The 12-item Short Form Health Survey (SF-12) was administered online to a sample of 3030 residents of the U.S. Gulf Coast in December 2017. Responses were scored to calculate mental component summary scores and physical component summary scores. Multiple linear regression models were fitted to identify predictors of self-rated health among the residents. Residents of U.S. Gulf Coast States have poorer self-rated physical and mental health compared to the U.S. population. Women and respondents reporting higher perception of flood risk had worse self-rated mental health, while hurricane evacuees, adults of at least 25 years of age, those with self-reported hurricane damage, and respondents reporting higher perception of surge risk had worse self-rated physical health. Residents of U.S. Gulf Coast States have poorer self-rated health compared to national standards. These findings may have practical implications for hurricane-associated physical and mental health services planning and delivery.

Confirmatory factor analysis and measurement invariance of the English, Mandarin, and Malay versions of the SF-12v2 within a representative sample of the multi-ethnic Singapore population

BACKGROUND

The Short Form Health Survey (SF-12v2) is an increasingly popular measure of health-related quality of life (HRQoL) in Singapore. In order to examine whether the SF-12v2 was appropriate for use in the population, the factor structure and validity of the English, Mandarin, and Malay versions were assessed in a representative sample of the general population of Singapore.

METHODS

6126 respondents were recruited for the Singapore Mental Health Study 2016 (SMHS 2016), a cross-sectional and population-based survey. Confirmatory factor analyses (CFA) were conducted to examine the fit of a two-factor model for the SF-12v2 within a representative sample and amongst the different language (English, Mandarin, Malay) subgroups. Multiple-group CFAs (MGCFA) were conducted to test measurement invariance across the different languages, ethnicities, and chronic illnesses subgroups. CFA-generated latent factor scores (FSCORE command in MPlus) were also compared with the composite scores derived from the developer's scoring method via correlations. Sociodemographic correlates of the latent physical and mental health scores were explored.

RESULTS

CFA results within the full sample supported a two-factor model (RMSEA = 0.044; CFI = 0.991; TLI = 0.988; SRMR = 0.044) in which physical functioning, role physical, bodily pain and general health items loaded onto a latent physical health factor, while role emotional, mental health, social functioning, and vitality items loaded onto a latent mental health factor. Physical and mental health factors were allowed to correlate, unlike the developer's orthogonal scoring method. All standardized loadings were high and statistically significant. Both factors had high internal consistency. CFA within subsamples of English, Mandarin, and Malay languages indicated similar findings. MGCFA results indicate that measurement invariance held across the different languages, ethnicities, and those with and without chronic illnesses.

CONCLUSION

The present study identified a two-factor (physical and mental health) structure within the general population and amongst the three different languages and demonstrated the measurement invariance of SF-12v2 across different subgroups. Findings indicate that algorithm-derived PCS and MCS should be interpreted with caution as they may result in inaccurate conclusions regarding the relationships between HRQoL and its correlates. Future studies using the SF-12v2 within the general population of Singapore should consider utilizing the factor structure put forth in the present study to obtain more appropriate estimates of HRQoL.

Studying physical and mental health status among hijra, kothi and transgender community in Kolkata, India

Individuals with diverse sexual orientation and gender identities have historically experienced the major share of stigma, discrimination, and marginalization among all the LGTBIQ+ communities in India. Transgender, intersex, or queer individuals are deprived of their basic rights, self-dignity, bodily autonomy, and healthcare leading to significant negative health status. Recent legal reforms such as the decriminalization of Section 377 of the Indian Penal Code (prohibited same-sex activity) and amendments to the Transgender Persons (Protection of Rights) Bill may improve their health. In this context, the study has the following objectives: 1) to measure the physical and the mental health status of hijra, kothi, and transgender (HKT) individuals using the Short Form 12 (SF-12) questionnaire; 2) understand the variation in their health status by social determinants; and 3) identify spatial patterns of HKTs general, physical, and mental health. Data was collected using a Bengali version of SF-12 (N = 98). We calculated physical (PCS) and mental (MCS) health composite scores and conducted relevant statistical and spatial analysis. Findings revealed that HKT individuals had poor mental health (mean MCS = 42.3) compared to their physical health (mean PCS = 49.0). ANOVA tests showed statistically significant variation of PCS and MCS among HKTs by their age and income. Participants with both poor and good health conditions were evenly distributed in the study area, with no significant spatial clustering. This study was the first attempt to assess the health-related quality of life among the HKT individuals using SF-12, not previously adapted to gender-diverse communities in India. Results clearly indicate that there is a pressing need to address both physical and mental health among gender-diverse communities by not only improving awareness of their healthcare rights but by also removing social and structural barriers to health programs, increasing targeted health interventions, grassroot level activism, and government advocacy.

Effect of tardive dyskinesia on quality of life in patients with bipolar disorder, major depressive disorder, and schizophrenia

PURPOSE

Tardive dyskinesia (TD) is a common but serious hyperkinetic movement disorder and side effect of antipsychotic medications used to treat bipolar disorder (BD), major depressive disorder (MDD), and schizophrenia (SZ). The purpose of this study was to evaluate health-related quality of life (HRQoL) in a population with diagnoses for BD, MDD, or SZ by comparing patients with TD (n = 197) with those without TD (n = 219). HRQoL in each group was also compared with HRQoL of the general population.

METHODS

This study employed a cross-sectional web-based survey. HRQoL was assessed by four instruments: the SF-12 Health Survey, Version 2 (SF-12v2), the Quality of Life Enjoyment and Satisfaction Questionnaire, Short Form (Q-LES-Q-SF), the Social Withdrawal subscale of the Internalized Stigma of Mental Illness Scale (SW-ISMI); and two questions on movement disorders.

RESULTS

Patients with TD had significantly worse HRQoL and social withdrawal than those without. The differences were more pronounced for physical HRQoL domains than for mental health domains. Patients with more-severe TD, assessed through either self-rating or clinician rating, experienced significantly worse HRQoL than did those with less-severe TD. The impact of TD was substantially greater in patients with SZ than in those with BD or MDD. Compared with the general population, patients with BD, MDD, or SZ experienced significantly worse HRQoL regardless of TD status, although this deficit in HRQoL was greater among those with TD.

CONCLUSIONS

The presence of TD is associated with worse HRQoL and social withdrawal. The most severe impact of TD is on physical aspects of patients' HRQoL.

Association of physical activity, sedentary time, and sleep duration on the health-related quality of life of college students in Northeast China

BACKGROUND

College life represents a key transitional period in the life of young adults that is marked by increased social engagement; living habits acquired during this period have implications on the future life of college students. Therefore, investigation of the determinants of health status of college students is a key imperative; however, there is limited evidence on the study of concomitant effects of physical activity (PA), sedentary time (ST), and sleep duration on the health-related quality of life (HRQOL) of college students.

METHODS

This cross-sectional survey was conducted at a medical university in Shenyang in Northeast China in 2017. The study group comprised 926 undergraduate students. Data were collected by a self-administered questionnaire. PA, ST, sleep duration, and HRQOL were measured using the international physical activity questionnaire (IPAQ)-Long Form and the Chinese version of the 12-Item Short-Form Health Survey (SF-12). The association of PA, ST, and sleep duration with the HRQOL was examined using independent t-test, Pearson Chi-squared test, and multivariate linear regression analysis.

RESULTS

After adjusting for potential confounding factors, students who reported high PA had significantly higher physical component summary (PCS) score in the total study population and among female students than those who reported low PA, whereas students who reported moderate PA had significantly higher PCS score only among female students (P < 0.05). In the total study population and among male students, students who slept for ≥9 h/day had significantly higher mental component summary (MCS) score than those who slept for 7-< 8 h/day, whereas among only male students, those who slept for 8-< 9 h/day had significantly higher MCS score (P < 0.05). The interaction term between ST and PA was not statistically significant.

CONCLUSIONS

PA and sufficient sleep duration had a positive impact on the HRQOL of college students; however, ST was not associated with HRQOL and there was no interaction between the impact of ST and PA on the HRQOL of college students. Increasing PA and promoting adequate sleep duration are key health promotion strategies for college students.

Differential item functioning of the SF-12 in a population-based regional joint replacement registry

Background

Joint replacement, an increasingly common procedure amongst older adults, can substantially improve health-related quality of life (HRQoL). However, differential item functioning (DIF) may affect the accurate interpretation of differences in HRQoL amongst patients with different demographic and health status characteristics but the same underlying (i.e., latent) level of the investigated construct. This study tested for DIF in pre-operative SF-12 physical health (PH) and mental health (MH) sub-scale items amongst patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA).

Methods

Data were from a population-based joint replacement registry from the Canadian province of Manitoba. TKA and THA patients who had surgery between 2009 and 2015 and completed a pre-operative assessment were included. DIF was tested using the multiple indicators multiple causes (MIMIC) method with sex, age group, body weight status, and presence of multiple comorbid conditions (i.e., multimorbidity) as covariates. Analyses were stratified by joint type.

Results

The study cohort included 8820 patients; 42.1% underwent THA, 57.3% were female, 32.7% were 70+ years, and 52.8% were obese. For each sub-scale, four of the six items exhibited DIF in both THA and TKA groups. Differences in the covariate effect estimates for DIF and No-DIF models on the MH latent variable were largest for age and body weight status for the THA group, and for sex and multimorbidity for the TKA group. All of the differences were small for PH. Multimorbidity had the strongest association with PH and age and sex had the strongest association with MH in the DIF models.

Conclusions

Demographic and health status characteristics influenced SF-12 PH and MH item responses in joint replacement populations, although the size of the effects were not large for PH. We recommend testing and adjusting for DIF effects to ensure comparability of HRQoL measures in joint replacement populations.

Electronic supplementary material

The online version of this article (10.1186/s12955-019-1166-1) contains supplementary material, which is available to authorized users.

Does Diagnosis Make a Difference? Estimating the Impact of an HIV Medication Adherence Intervention for Persons with Serious Mental Illness

The heightened risk of persons with serious mental illness to contract and transmit human immunodeficiency virus (HIV) is a public health problem. Here we evaluate the interaction between psychiatric diagnosis and response to a community based-intervention targeted at treatment adherence in 236 HIV+ persons with co-occurring mental illness. To examine differential effectiveness of the intervention for categories of patient diagnosis, we reanalyzed the data after stratifying participants into two diagnostic groups: (1) participants with depressive disorders without psychosis and (2) participants with a psychotic or bipolar disorder. Outcomes included viral load and mental health quality of life (SF-12 Mental Health). We found that HIV+ persons with non-psychotic depressive disorders demonstrated a larger decrease in HIV viral load and more improvement in measures of mental health quality of life when compared to HIV+ persons with psychotic and bipolar disorders. We suggest that successful adherence interventions should be informed by psychiatric symptomatology.

TRIAL REGISTRATION

clinicaltrials.gov 29 identifier NCT00264823.

Impact of oral potentially malignant disorders on quality of life

BACKGROUND

Oral potentially malignant disorders (OPMDs) could have a significant psychological impact on patients, principally because of the unknown risk of malignant transformation, while the physical and functional impairments could differ. This study aimed to assess the impact of three different OPMDs and their disease stages on the quality of life (QoL) of affected patients.

METHODS

Oral leukoplakia (OL), oral lichen planus (OLP) and oral submucous fibrosis (OSF) patients who were undergoing treatment at an oral medicine clinic of a dental teaching hospital in India were the study population. All subjects completed the recently developed OPMDQoL questionnaire and a short form 12 item (version 2) health survey questionnaire (SF-12v2). OPMDQoL questionnaire consists of 20 items over four dimensions. A higher score denotes poor OHRQoL. SF-12v2 has two components, a Physical Component Summary (PCS) and Mental Component Summary (MCS).

RESULTS

A total of 150 subjects (50 each of OL, OLP and OSF) participated. OL patients (37.7 ± 7.9) reported significantly better OPMDQoL scores than OLP (47.3 ± 5.8) and OSF (45.4 ± 9.2) patients. OLP patients reported significant problems in obtaining a clear diagnosis for their condition, more so than the other OPMDs. OL patients reported fewer problems for the dimension, "physical impairment and functional limitations" than the OLP and OSF patients. A significant trend was observed with the overall OPMDQoL and MCS, deteriorating as the disease stage increased.

CONCLUSIONS

OLP and OSF have a significant impact on the QoL of affected individuals: OL less so. Increasing stage of the disease is associated with worsening QoL.

Examining gender-related differential item functioning of the Veterans Rand 12-item Health Survey

PURPOSE

Previous research suggests that gender differences in patient-reported outcome measures (PROMs) may reflect measurement bias rather than true differences in underlying health status. The aim of this study is to examine whether the Veterans Rand 12-item Health Survey (VR-12) allows for unbiased comparisons of physical and mental health scores across gender. The VR-12 is a generic PROM consisting of 12 items with 3-6 response options for the measurement of mental and physical health.

METHODS

Study data were from the 2015 Health Outcomes Survey pertaining to the Medicare beneficiaries. A total of 277,518 participants included 116,817 (42.1%) males and 160,701 (57.9%) females. Scale-level and item-level differential functioning methods were applied using multiple-group confirmatory factor analysis and ordinal logistic regression, respectively.

RESULTS

The scale-level differential functioning showed support for strict invariance (RMSEA = 0.045; CFI = 0.995) across gender. Although we found statistically significant differential item functioning for several items, the magnitude was negligible (maximum ΔR ² = 0.007).

CONCLUSION

The VR-12 physical and mental health status scores are unbiased with respect to gender.