Sex bias in referral of women to outpatient cardiac rehabilitation? A meta-analysis

Background: Cardiovascular disease continues to be among the leading causes of morbidity and mortality among men and women globally. However, research suggests that women are significantly underrepresented in cardiac rehabilitation (CR), programmes which are shown to reduce recurrent cardiac events and related premature death. However, sex differences in referral rates have not been systematically and quantitatively reviewed. Hence, the objective of the study was to assess whether a significant sex difference exists.

Methods: We searched Scopus, MEDLINE, CINAHL, PsycINFO, PubMed, and The Cochrane Library databases for studies reporting CR referral rates in women and men published between July 2000 and July 2011. Titles and abstracts were screened, and the selected full-text articles were independently screened based on predefined inclusion/exclusion criteria. Included articles were assessed for quality using STROBE.

Results: Of 623 screened articles, 19 observational studies reporting data for 241,613 participants (80,505 women) met the inclusion criteria. In the pooled analysis, women (39.6%) were significantly less likely to be referred to CR compared to men (49.4%; odds ratio 0.68, 95% confidence interval 0.62-0.74). Heterogeneity was considered significant (I (2 )= 90%). There was no change in significant findings when subgroup analyses were conducted, examining fee for service vs. no fee, high-quality studies vs. others, or studies pooled by different study methodologies.

Conclusions: CR referral remains low for all patients, but is significantly lower for women than men. Evidence-based interventions to increase referral for all patients, including women, need to be instituted. It is time to ensure broader implementation of these strategies.