Brief summary:
Background: Heart Failure (HF) is the second most common cause of hospitalizations for women in North America. Non-adherence to guideline-directed medical therapy (GDMT) is associated with 50% of all treatment failures and high rates of hospitalizations and death. A recent Canadian study showed that adherence to three or more GDMT medications occurred in only 20% of Canadian HF patients. Despite clear guidelines on the pharmacologic management of HF and the introduction of new and effective drugs, adherence to GDMT in women with HF is low. Furthermore, the rates of hospitalizations have not improved in Canada over the last decade, and mortality in Canadian women with HF remains high. One explanation may be that social determinants of health (SDOH), which are known to be strong predictors of both adherence and adverse outcomes in HF, have not specifically been targeted to improve either adherence or outcomes in HF. Social prescribing (SP) is an innovative, non-medical intervention that aims to improve health by addressing SDOH. However, whether using SP to LINK clinical and social services for the benefit of socially vulnerable HF women can improve outcome is unknown. By targeting SDOH, which are strong predictors of adherence and outcomes in HF, and which have been shown to disproportionately disfavor women, SP has the potential to significantly improve medication adherence, quality of life and outcomes in women with HF.
Objectives: The overall aim of this study is to assess whether SP, through individualized, SDOH-targeted interventions, can improve adherence and quality of life in Canadian women with HF and at high risk for no adherence. Primary objective: To determine whether SP can improve adherence to GDMT. Secondary objective: To determine whether SP can improve quality of life.
Methods: This is an intention to treat, multicenter (five centers), and open-labeled, randomized clinical trial. Women with HF with two or more points on a weighted SDOH questionnaire (SPARK tool) will be randomly assigned to either SP or control group. Women in the SP group will meet with a link worker (LW) who will perform SP. SP will consist of personalized referrals to non-medical supports or services based on women's specific SDOH-related vulnerabilities and social needs. SP will address social needs such as issues with income, unemployment, transportation, mobility, dependents, housing, loneliness, mental health, health literacy, medication management and medical appointment schedules. Social prescriptions will be based on the interview conducted by the LW and will prioritize SDOH-related vulnerabilities identified on the SPARK questionnaire. Participants in the control group will receive standard care as is typically offered in the current specialized HF clinic in the participating centers. Controls will not meet with a LW, but, as usual, their physician or treating team may refer them to any specialists or services deemed necessary.
Outcome measures: The primary outcome will be adherence to GDMT measured with PDC obtained from provincial administrative databases and the secondary outcome will be quality of life measures including physical limitations, social limitations, as measured with the Kansas City Cardiomyopathy Questionnaire (KCCQ-12).
Sample size Calculations: The sample size was calculated using the primary outcome of adherence to GDMT measured with PDC as a continuous variable. In one observational study on adherence to HF medications which compared women and males adherence using PDCs, adherence in women was 63% with a SD of 23%. The impact of an absolute increase of 10% in PDC on clinical end points was considered significant. Using an alpha of 0.05 and a power of 0.80, a minimum of 166 participants would be needed to detect a statistically significant difference. Based on pilot data, the proportion of women followed in heart failure clinics is 28% and the proportion of eligible women (i.e. 1 point or more on the SPARK questionnaire) is about 30%. Considering a 30% refusal rate and a 5% dropout rate (intention to treat with registry based outcome), the five chosen centers should totalize 188 participants. The secondary outcome, the KCCQ, is a continuous variable for which a change of five points or more (5%) is considered clinically significant. Using an alpha of 0.05 and a power of 0.80, 126 patients would be required to detect such a difference.
Significance: SP holds immense potential for women with HF by addressing critical gaps in care. SP may help bridge the gap between healthcare providers and community resources, providing tailored support addressing SDOH that disproportionately affect women with HF. SP has the potential to significantly enhance adherence to GDMT, which has been shown to greatly, reduce hospitalizations and mortality in this vulnerable population.