Domestic abuse increases risk for all mortality causes

New findings from the Journal of the American Heart Association indicate that domestic abuse (DA) against women can increase mortality from all causes by 40% when compared to rates in the general population. An estimated one in three women globally have experienced domestic abuse at some point in their life.

Methods
The retrospective cohort study consisted of UK-based primary care patients seen between January 1, 1995 and December 1, 2017. Data were collected from the Health Improvement Network (THIN) database and women who had been coded with previous exposure to DA were matched with women who had not been exposed. Each exposed woman was matched to up to four women based on age at index date (± 1 year), body mass index (to within 2 kg/m²), smoking status, and Townsend deprivation score at baseline. The primary outcome was development of cardiometabolic disease, exploring the outcomes of cardiovascular disease (CVD) (ischemic heart disease [IHD], heart failure, peripheral vascular disease, and stroke or transient ischemic attack [TIA] during the observation period), hypertension, and type 2 diabetes mellitus (T2DM).

Findings
A total of 18,547 women who had experienced DA were matched to 73,231 unexposed women as controls. Mean length of follow-up was shorter at 2.2 ± 2.3 years in the exposed group compared with 3.1 ± 2.7 years in the unexposed group. This was a result of exposed women transferring practice more often than unexposed women. The mean age (37 years) was similar in both exposed and unexposed groups. Both groups had a high prevalence of smoking (44.7%) and high Townsend deprivation scores compared with the national UK average. Furthermore, women in the exposed group also had a significantly higher prevalence (10.1%) of excessive drinking at baseline compared with 3.5% in the unexposed group. The exposed group also had a higher proportion of patients with T2DM, greater comorbidity, higher prevalence of hypertension, and more use of lipid-lowering medications. 

During the study period, 181 women (IR: 3.1 per 1000 person years) in the exposed group, compared with 644 women from the control group (IR: 2.3 per 1000 per 1000 person-years), developed a cardiovascular disease (CVD) outcome. The adjusted IRR of composite CVD was 1.31 (95% CI, 1.11 - 1.55; P = 0.001). The DA-exposed group had a significantly higher risk of developing IHD (1.40, 95% CI 1.09 – 1.79; P = 0.007) and stroke or transient ischemic attack (TIA) (1.29, 95% CI 1.02 – 1.63; P= 0.035). The authors found no statistically significant differences between the likelihood of developing heart failure or peripheral vascular disease. 

In the exposed group, 316 women developed hypertension (IR: 5.7 per 1000 person-years) compared with 1496 women in the unexposed group (IR: 5.6 per 1000 person-years). The authors did not find any associations between DA and hypertension (IRR: 0.99, 95% CI 0.88 - 1.12; P= 0.873). Also, in the exposed group, 222 women (IR; 3.8 per 1000 person-years) developed T2DM compared with 678 women (IR 2.4 per 1000 person -years). The risk of developing T2DM was found to be higher in the exposed cohort than in the unexposed cohort (IRR 1.51, 95% CI 1.30 – 1.76; P < 0.001).  

Conclusions
Based on their findings, the authors believe that exposure to domestic abuse significantly increases a woman’s risk for mortality in all causes. They note that physicians should pay particular notice to managing risk factors for CVD and T2DM in this group. However, future studies are needed to confirm the relationship among other cohorts and more research is needed to understand the biological plausibility between DA exposure and subsequent development of cardiometabolic disease.