Published norms underestimate the health-related quality of life among persons with type 2 diabetes

Abstract Objective To assess health-related quality of life (HRQL) among adults with type 2 diabetes using the Short Form (SF)-36 and to obtain pooled estimates of HRQL for subpopulations defined by demographic characteristics, diabetes-related complications, and comorbidities. Study Design and Methods We conducted computerized searches of multiple electronic bibliographic databases, and studies in any language were selected in which HRQL was reported among adults with type 2 diabetes using the SF-36. Estimates were combined using a random-effects model. Results One hundred eighteen studies fulfilled the inclusion criteria. HRQL was lower in persons with type 2 diabetes, as measured by all the eight component scores of the SF-36 when compared with the existing U.S. population norms and with previously published type 2 diabetes norms. SF-36 component and summary scores were extremely heterogeneous, and subpopulation data were sparse; this precluded obtaining meaningful pooled scores for most populations of interest and made comparisons among subpopulations difficult. Conclusion Our data suggest that previously published norms may underestimate the effect of diabetes on HRQL, and diabetes populations are extremely heterogeneous, making broad population "norms" for HRQL in type 2 diabetes of limited use. Additional research with important subpopulations and individual-level data are needed to further explore the effect of diabetes on HRQL.