Refusal to participate in heart failure studies: do age and gender matter?

The objective of this retrospective study was to evaluate reasons heart failure patients decline study participation, to inform interventions to improve enrollment.

Failure to enrol older heart failure patients (age > 65) and women in studies may lead to sampling bias, threatening study validity.

This study was a retrospective analysis of refusal data from four heart failure studies that enrolled 788 patients in four states.

Chi-Square and a pooled t-test were computed to analyse refusal data (n = 300) obtained from heart failure patients who were invited to participate in one of the four studies but declined.

Refusal reasons from 300 patients (66% men, mean age 65·33) included: not interested (n = 163), too busy (n = 64), travel burden (n = 50), too sick (n = 38), family problems (n = 14), too much commitment (n = 13) and privacy concerns (n = 4). Chi-Square analyses showed no differences in frequency of reasons (p > 0·05) between men and women. Patients who refused were older, on average, than study participants.

Some reasons were patient-dependent; others were study-dependent. With 'not interested' as the most common reason, cited by over 50% of patients who declined, recruitment measures should be targeted at stimulating patients' interest. Additional efforts may be needed to recruit older participants. However, reasons for refusal were consistent regardless of gender.

Heart failure researchers should proactively approach a greater proportion of women and patients over age 65. With no gender differences in type of reasons for refusal, similar recruitment strategies can be used for men and women. However, enrolment of a representative proportion of women in heart failure studies has proven elusive and may require significant effort from researchers. Employing strategies to stimulate interest in studies is essential for recruiting heart failure patients, who overwhelmingly cited lack of interest as the top reason for refusal.