Differences in lipid treatment patterns in women versus men in a large cohort of patients with atherosclerotic cardiovascular disease in Ontario, Canada
Authors: Fairbairn M , Goeree R , Goodman S.G , Rogoza R.M , Packalen M , Motsepe-Ditshego P , Pericleous L , Oh P 
Published: November 2020

Abstract

Background/Introduction
The prevalence of ischaemic heart disease is lower in women vs men in Canada. Studies have shown that women are more likely to be underdiagnosed and less likely to receive guideline-recommended treatments than men. Women receiving lipid-lowering therapies (LLTs) are also less likely to attain treatment goals vs men.

Purpose
We analysed use of LLTs and attainment of low-density lipoprotein cholesterol (LDL-C) treatment goals in a recent longitudinal cohort of patients with ASCVD with public drug coverage in Ontario to describe differences observed between female and male patients.

Methods
Patients ≥65 years with a primary ASCVD event/procedure between 1 Apr 2005 and 31 Mar 2016, treated with an LLT and with index and follow up LDL-C values were identified from claims data at the Institute for Clinical Evaluative Sciences data repository. Patients were assessed over a 1 year follow up period for LDL-C goal attainment (&lt;2.0 mmol/L or 50% reduction from index LDL-C as per Canadian Cardiovascular Society Guidelines) and analysed by LLT category.

Results
143,302 patients with ASCVD ≥65 years on LLTs were identified of which 41% were female. A higher proportion of female vs male patients were prescribed low (3% vs 2%) and medium intensity statins (51% vs 44%) compared with high intensity statins (43% vs 52%). A higher proportion of women failed to attain LDL-C goal compared to men (33% vs 24%) (Figure). When analysed by low, moderate or high intensity statin, 65%, 35%, and 27% of female patients and 49%, 25% and 19% of male patients failed to attain LDL-C goal at follow up.

Conclusions
In this retrospective study, women with a diagnosis of ASCVD were more frequently treated with low/moderate intensity statins whereas men were more frequently treated with high intensity statins. Approximately 2 of 3 women and 3 of 4 men receiving statin treatment attained LDL-C goal during the 1-year follow up period. Overall, there appear to be treatment differences between female and male patients with ASCVD, with males receiving higher intensity statin therapy and attaining LDL-C goal more frequently. Further research is needed to determine why these discrepancies exist.
This study made use of de-identified data from the ICES Data Repository, which is managed by the Institute for Clinical Evaluative Sciences with support from its funders and partners: Canada's Strategy for Patient-Oriented Research (SPOR), the Ontario SPOR Support Unit, the Canadian Institutes of Health Research and the Government of Ontario. The opinions, results and conclusions reported are those of the authors. No endorsement by ICES or any of its funders or partners is intended or should be inferred. Parts of this material are based on data and/or information compiled and provided by CIHI. However, the analyses, conclusions, opinions and statements expressed in the material are those of the author(s), and not necessarily those of CIHI.
Figure 1

Funding Acknowledgement
Type of funding source: Private company. Main funding source(s): Amgen Canada Inc