Naleen Raj Bhandari

Reliability and Validity of the Medical Outcomes Study Short Form-12 Version 2 (SF-12v2) in Adults with Non-Cancer Pain

Limited evidence exists on how non-cancer pain (NCP) affects an individual’s health-related quality of life (HRQoL). This study aimed to validate the Medical Outcomes Study Short Form-12 Version 2 (SF-12v2), a generic measure of HRQoL, in a NCP cohort using the Medical Expenditure Panel Survey Longitudinal Files. The SF Mental Component Summary (MCS12) and SF Physical Component Summary (PCS12) were tested for reliability (internal consistency and test-retest reliability) and validity (construct: convergent and discriminant; criterion: concurrent and predictive). A total of 15,716 patients with NCP were included in the final analysis. The MCS12 and PCS12 demonstrated high internal consistency (Cronbach’s alpha and Mosier’s alpha > 0.8), and moderate and high test-retest reliability, respectively (MCS12 intraclass correlation coefficient (ICC): 0.64; PCS12 ICC: 0.73). Both scales were significantly associated with a number of chronic conditions (p < 0.05). The PCS12 was strongly correlated with perceived health (r = 0.52) but weakly correlated with perceived mental health (r = 0.25). The MCS12 was moderately correlated with perceived mental health (r = 0.42) and perceived health (r = 0.33). Increasing PCS12 and MCS12 scores were significantly associated with lower odds of reporting future physical and cognitive limitations (PCS12: OR = 0.90 95%CI: 0.89–0.90, MCS12: OR = 0.94 95%CI: 0.93–0.94). In summary, the SF-12v2 is a reliable and valid measure of HRQoL for patients with NCP.

Assessment of Reliability and Validity of SF-12v2 among a Diabetic Population

OBJECTIVES To validate the Medical Outcomes Study Short Form version 2 (SF-12v2) in diabetic patients. METHODS Adults with self-reported diabetes from the Medical Expenditure Panel Survey (2011-2013) were identified. Reliability (internal consistency and test-retest) and validity (construct, concurrent, criterion, and predictive) of the SF-12v2 were assessed. The SF-12v2 consists of two normalized composite scores: the physical component summary score (PCS12) and the mental component summary score (MCS12). Confirmatory factor analysis was conducted to assess the instrument structure. Concurrent (convergent and discriminant) validity was assessed by a multitrait-multimethod matrix using the Patient Health Questionnaire, the Kessler Scale, and perceived health and mental health questions. The predictive validity was assessed by estimating future limitations. The concurrent validity was tested by comparing the MCS12, PCS12, and utility scores (six-dimensional health state short form) across comorbidity scores. RESULTS The final sample comprised 2214 diabetic patients with mean normalized (population mean 50; range 0-100) PCS12 and MCS12 scores of 40.81 (standard error 0.33) and 49.82 (standard error 0.26), respectively. The PCS12 and MCS12 scores showed good internal consistency (Cronbach α: PCS12 0.85; MCS12 0.83) and acceptable test-retest reliability (intraclass correlation coefficient: PCS12 0.72; MCS12 0.63) and produced acceptable goodness-of-fit indices (normed fit index 0.95; comparative fit index 0.95; root mean square error of approximation 0.11 [95% confidence interval 0.1017-0.1188]). The PCS12 and MCS12 were moderately correlated with perceived health and perceived mental health. The MCS12 was highly correlated with the Patient Health Questionnaire and the Kessler Scale. Both the PCS12 and the MCS12 could predict the future health limitations. The PCS12, MCS12, and utility scores demonstrated sensitivity to the presence of comorbidity scores. CONCLUSIONS The SF-12v2 is a valid generic instrument for measuring quality of life in diabetic patients.

Reliability and validity of SF-12v2 among adults with self-reported cancer

Background: The SF‐12v2 has been validated in general population and other conditions but the evidence is limited in Americans with cancer. Objective: To assess reliability and validity of SF‐12v2 among adults with self‐reported cancer using the Medical Expenditure Panel Survey (MEPS). Methods: Self‐reported cancer participants (SCPs) were identified from 2003 MEPS. SF‐12v2 was administered as part of self‐administered questionnaires. Physical (PCS12) and mental (MCS12) component scores of SF‐12v2 were evaluated for reliability (internal consistency, test‐retest) and validity (convergent, discriminant, predictive, concurrent). Results: 420 SCPs were identified with average age of 59.3 years (SE=0.9). 10.7% had multiple cancers (>1) and 52% had at least one other chronic condition (OCC). Average PCS12 and MCS12 were 45.09 (SE=0.5) and 50.75 (SE=0.5). PCS12 and MCS12 demonstrated high internal consistency (&agr;PCS12=0.89; &agr;MCS12=0.88), acceptable test‐retest reliability (ICCPCS12=0.82; ICCMCS12=0.73), strongly correlated with most of the expected EQ‐5D domains (r=0.51–0.71), and demonstrated strong convergent validity on perceived health (r=0.61) and perceived mental health (r=0.52). PCS12 and MCS12 were able to discriminate between groups with and without physical/cognitive limitations. Only PCS12 was negatively correlated with number of OCCs. Conclusion: The SF‐12v2 is a reliable and valid instrument to quantify health‐related quality of life among adults with self‐reported cancer.