Purpose: Pulmonary rehabilitation (PR) programs have been shown to improve functional status, exercise performance, and quality of life (QOL) and decrease perception of exertion in individuals with chronic obstructive pulmonary disease. The purpose of this study was to identify the dose effect of PR on the outcome variables of activity level, perceived exertion, and physical and mental QOL.
Methods: The study used a retrospective explanatory design. The sample (N = 104) included records of individuals diagnosed with chronic bronchitis and emphysema who attended a PR program from 2000 to 2005 at a Midwest inner-city, academic medical center. Participants attended rehabilitation sessions 2 to 3 days per week for approximately 90 minutes each day; maximum duration of the program was 3 months (24 sessions). The PR dose was calculated by multiplying the number of PR sessions with the number of weeks attended.
Results: There were 32 men and 72 women, with a mean age of 59.9 years +/- 10.2 years. All patients were retired or unemployed, and 99% used oxygen during exercise. A higher PR dose was significantly related to improvement in activity level measured by maximum metabolic equivalent (MET) level achieved. A nonsignificant but minimally clinically important difference was found on the Medical Outcomes Study Short-Form 36 (SF-36) outcomes of mental and physical QOL.
Conclusions: The findings of the current study support a significant relationship between PR dose and activity level (maximum MET level achieved). Physical and mental QOL improved clinically after PR. Optimal program outcomes were related to greater patient participation in supervised PR.