Do deficits in cardiac care influence high mortality rates in schizophrenia? A systematic review and pooled analysis

Abstract

We have previously documented inequalities in the quality of medical care provided to those with mental ill health but the implications for mortality are unclear. We aimed to test whether disparities in medical treatment of cardiovascular conditions, specifically receipt of medical procedures and receipt of prescribed medication, are linked with elevated rates of mortality in people with schizophrenia and severe mental illness. We undertook a systematic review of studies that examined medical procedures and a pooled analysis of prescribed medication in those with and without comorbid mental illness, focusing on those which recruited individuals with schizophrenia and measured mortality as an outcome. From 17 studies of treatment adequacy in cardiovascular conditions, eight examined cardiac procedures and nine examined adequacy of prescribed cardiac medication. Six of eight studies examining the adequacy of cardiac procedures found lower than average provision of medical care and two studies found no difference. Meta-analytic pooling of nine medication studies showed lower than average rates of prescribing evident for the following individual classes of medication; angiotensin converting enzyme inhibitors (n = 6, aOR = 0.779, 95% CI = 0.638-0.950, p = 0.0137), beta-blockers (n = 9, aOR = 0.844, 95% CI = 0.690-1.03, p = 0.1036) and statins (n = 5, aOR = 0.604, 95% CI = 0.408-0.89, p = 0.0117). No inequality was evident for aspirin (n = 7, aOR = 0.986, 95% CI = 0.7955-1.02, p = 0.382). Interestingly higher than expected prescribing was found for older non-statin cholesterol-lowering agents (n = 4, aOR = 1.55, 95% CI = 1.04-2.32, p = 0.0312). A search for outcomes in this sample revealed ten studies linking poor quality of care and possible effects on mortality in specialist settings. In half of the studies there was significantly higher mortality in those with mental ill health compared with controls but there was inadequate data to confirm a causative link. Nevertheless, indirect evidence supports the observation that deficits in quality of care are contributing to higher than expected mortality in those with severe mental illness (SMI) and schizophrenia. The quality of medical treatment provided to those with cardiac conditions and comorbid schizophrenia is often suboptimal and may be linked with avoidable excess mortality. Every effort should be made to deliver high-quality medical care to people with severe mental illness.

Figure 1.

Revascularization procedure rate ratios (95% confidence intervals) comparing users of mental health services with the general community, by procedure type and principal psychiatric diagnosis. (Data adapted from Lawrence et al. (2003)).