Patient Characteristics and Outcomes by Sex and Smoking Status in Pulmonary and Cardiac Rehabilitation

Introduction: Those with established symptomatic cardiopulmonary disease should attend secondary prevention programs. Attendance at these programs is known to differ by sex and smoking status, with females and those who smoke being less likely to attend. However, little is known about whether the risk factors of being female and smoking are cumulative, and how outcomes from secondary prevention differ by these subgroups. Accordingly, we sought to examine patient characteristics at entry and outcomes of those attending pulmonary (PR) and cardiac rehabilitation (CR) by sex and smoking status. Aims and Methods: Data were from patients enrolled in programs participating in a national registry between 2013 and 2021 (PR) or 2012 and 2021 (CR). Variables examined included: age, sex, race, educational attainment, insurance coverage, qualifying diagnosis, BMI, number of PR/CR sessions attended, baseline, and change in, psychosocial (depression and anxiety symptoms) and physical function and fitness measures (6-minute walk distance [6MWD]/metabolic equivalents [METs]). Results: Analyses included 41 087 PR and 447 921 CR patients. Current smoking was reported in 14.3% (PR) and 8.4% (CR) of patients. Across PR/CR, at baseline, current smoking and female sex were both associated with higher depression scores, lower fitness/function measures, and fewer sessions. Both current smoking and female sex were significantly associated with less improvement in 6MWD, METs, and depression scores within CR. Conclusions: Both sex and smoking status are important risk factors for those entering secondary prevention programs. Females who smoke have higher risk factors at entry, attend fewer sessions, and, within CR, improve less in fitness/function. Implications: This study uses large national registries to replicate and expand upon prior findings that both female sex and current smoking are associated with higher-risk profiles when entering secondary prevention programs. Additionally, this study demonstrates that current smoking and female sex are also associated with less improvement during secondary prevention, especially within cardiac rehabilitation.