Murali Sundaram (Department of Pharmaceutical Systems and Policy, School of Pharmacy, West Virginia University, Morgantown, West Virginia, USA) Jan Kavookjian (Department of Pharmacy Care Systems, Harrison School of Pharmacy, Auburn University, Alabama, USA) Julie Hicks. Patrick (Department of Psychology, West Virginia University, Morgantown, West Virginia, USA)
Abstract
Background and objectives: Health-related quality of life (HR-QOL) and quality of life (QOL) are increasingly being examined as outcomes in assessments among patients with type 2 diabetes mellitus. However, there is a lack of standardization in interpreting the two outcomes and insufficient appreciation of the differences between HR-QOL and QOL. This study reports relationships between two instruments of HR-QOL and an instrument of QOL in a cross-sectional study of patients with type 2 diabetes. Abstract: Methods: Patients with type 2 diabetes at the outpatient clinics of a university hospital completed measures of generic health status (12-item Short-Form Health Survey [SF-12], version 2 and EQ-5D) and diabetes-specific QOL (Audit of Diabetes Dependent Quality of Life [ADDQoL]). Patient-reported data were merged with retrospective clinical data including glycosylated hemoglobin (HbA1c), co-morbidities, diabetes complications score, body mass index (BMI), and others, obtained from electronic medical records. A path model of our hypothesized relationships between the physical and psychological components of HR-QOL, overall HR-QOL, and QOL was tested in addition to examining bivariate correlations between these constructs. The fit of the path model was assessed using multiple indexes of fit, including an overall chi-squared (χ) test, the Comparative Fit Index (CFI), the Tucker-Lewis Index (TLI), and the Root Mean Square Error Approximation (RMSEA). The differences in the association between clinical, medical history and sociodemographic variables with HR-QOL and QOL were explored employing univariate t-tests and ANOVAs as well as multiple regression models. Abstract: Results: The usable response rate was 44.3% (n - 385). The mean HbA1c of respondents was 7.2% (±1.4), mean duration of diabetes was 10.2 (±9.1) years, and 62.1% were obese (BMI ≥30 kg/m). About 49% of respondents were taking oral medications only, 31.7% were taking oral medications and insulin, and 9.4% were taking insulin only. Spearman correlations of the EQ-5Dindex were 0.640 with the SF Physical Component Score (PCS)-12, 0.534 with the SF Mental Component Score (MCS)-12, and 0.316 with the ADDQoL (all p < 0.001). A path analytic model relating SF-12 scores with EQ-5Dindex and ADDQoL scores exhibited good fit (χ - 1.32; p - 0.250; CFI - 0.99; TLI - 0.99; RMSEA - 0.03). Insulin use and diabetes-related complications were significantly associated with poorer scores on all measures. Only ADDQoL scores were significantly better among those with the American Diabetes Association-recommended HbA1c level of <7.0% (p - 0.002). Obesity was significantly associated with impaired SF-12 and EQ-5Dindex scores but not ADDQoL scores, while depressive symptoms were significantly associated with poorer scores on all these measures. The included explanatory variables explained a greater proportion of the variance in HR-QOL (PCS-12, MCS-12, EQ-5Dindex) than in QOL (ADDQoL) scores. Abstract: Conclusion: The study found that HR-QOL measures showed small correlations with the impact of diabetes on QOL. The fit statistics supported the hypothesized relationships in the path model, and provided empirical evidence that HR-QOL is a subset of QOL. In comparison to HR-QOL, QOL was less explained by the included explanatory variables, suggesting a greater influence on QOL by factors not accounted for in the present study.
Download Info
To download:
If you experience problems downloading a file, check if you have the
proper application to
view it first. Information about this may be contained
in the File-Format links below. In case of further problems read
the IDEAS help
page. Note that these files are not on the IDEAS
site. Please be patient as the files may be large.
As the access to this document is restricted, you may want to look for a different version under "Related research" (further below) or search for a different version of it.
For technical questions regarding this item, or to correct its listing, contact: (Remco Bouckaert).
Related research
Keywords:
Find related papers by JEL classification: C - Mathematical and Quantitative Methods D - Microeconomics I - Health, Education, and Welfare Z - Other Special Topics I1 - Health, Education, and Welfare - - Health I19 - Health, Education, and Welfare - - Health - - - Other I18 - Health, Education, and Welfare - - Health - - - Government Policy; Regulation; Public Health I11 - Health, Education, and Welfare - - Health - - - Analysis of Health Care Markets