The purpose of this study was to investigate further the effect of medical comorbidity on a patient reported shoulder specific health related quality of life (HRQoL) measure. We investigated which types of comorbidities have a detrimental effect upon shoulder specific HRQoL. We hypothesized that general medical comorbidity would not negatively affect shoulder specific HRQoL questionnaires, but that comorbidities specific to the chest region would, when properly controlling for other patient factors.
A cohort of 173 consecutive patients who underwent shoulder surgery for osteoarthritis and/or rotator cuff repair was extracted from a clinical outcomes database. Their health related quality of life (HRQoL) was evaluated with the University of Pennsylvania (PENN) shoulder score and the Short Form-36 (SF-36). Nonadjusted and multivariate risk-adjusted models were built to investigate the effect of medial comorbidity on shoulder specific HRQoL and were tested using linear modeling.
Nonadjusted models showed patients with more total comorbidities (P=.01) and more chest-related comorbidities (P=.006) had lower PENN scores. But, when risk adjusting for other patient factors, the PENN scores decreased with an increase in the number of chest comorbidities (P=.008), but not the number of total comorbidites (P=.391) or other (nonchest) comorbidities (P=.163).
Shoulder specific HRQoL measures are joint specific, but they are influenced by disease or conditions that affect the chest region. This may be important in understanding why patients with certain comorbid diseases report worse shoulder pain and function and may respond differently to treatment over time.