Statin prescribing for people with severe mental illnesses: a staggered cohort study of ‘real-world’ impacts

Abstract

ObjectivesTo estimate the ‘real-world effectiveness of statins for primary prevention of cardiovascular disease (CVD) and for lipid modification in people with severe mental illnesses (SMI), including schizophrenia and bipolar disorder.DesignSeries of staggered cohorts. We estimated the effect of statin prescribing on CVD outcomes using a multivariable Poisson regression model or linear regression for cholesterol outcomes.Setting587 general practice (GP) surgeries across the UK reporting data to The Health Improvement Network.ParticipantsAll permanently registered GP patients aged 40–84 years between 2002 and 2012 who had a diagnosis of SMI. Exclusion criteria were pre-existing CVD, statin-contraindicating conditions or a statin prescription within the 24 months prior to the study start.ExposureOne or more statin prescriptions during a 24-month ‘baseline’ period (vs no statin prescription during the same period).Main outcome measuresThe primary outcome was combined first myocardial infarction and stroke. All-cause mortality and total cholesterol concentration were secondary outcomes.ResultsWe identified 2944 statin users and 42 886 statin non-users across the staggered cohorts. Statin prescribing was not associated with significant reduction in CVD events (incident rate ratio 0.89; 95% CI 0.68 to 1.15) or all-cause mortality (0.89; 95% CI 0.78 to 1.02). Statin prescribing was, however, associated with statistically significant reductions in total cholesterol of 1.2 mmol/L (95% CI 1.1 to 1.3) for up to 2 years after adjusting for differences in baseline characteristics. On average, total cholesterol decreased from 6.3 to 4.6 in statin users and 5.4 to 5.3 mmol/L in non-users.ConclusionsWe found that statin prescribing to people with SMI in UK primary care was effective for lipid modification but not CVD events. The latter finding may reflect insufficient power to detect a smaller effect size than that observed in randomised controlled trials of statins in people without SMI.

Primary care management of cardiovascular risk for people with severe mental illnesses: the Primrose research programme including cluster RCT

“…This study aimed to examine the effectiveness of statins for people with SMI through a systematic review of existing evidence and a series of staggered cohort studies designed to estimate the effectiveness of statins for the prevention of CVD and for modifying lipids in people with SMI. 102 This study was published in the journal BMJ Open in 2017. 102 The link to this paper can be found in Appendix 3, Work package 2.…”

“…102 This study was published in the journal BMJ Open in 2017. 102 The link to this paper can be found in Appendix 3, Work package 2. 102 Although statins form a core part of CVD primary prevention in the general population, this evidence base was not readily transferable to people with SMI.…”

“…102 The link to this paper can be found in Appendix 3, Work package 2. 102 Although statins form a core part of CVD primary prevention in the general population, this evidence base was not readily transferable to people with SMI. This is because it is not known whether or not patterns of medication adherence differ.…”

“…Regarding the statins database research in Primrose, 102 it is important that further studies monitor the national prescribing of statins to people with SMI, especially older age groups who are undertreated in current UK practice.…”

“…101,102 The work within work package 2.3 was also the content of a successful PhD awarded to Ruth Blackburn in 2016 as part of Primrose 118. Bringing the evidence together to develop and test the Primrose trial intervention and training programmeAt the end of the development work packages, we entered an intensive period of work, synthesising the evidence that we had identified, running workshops and developing the manual and training programme for the Primrose nurse-led intervention.…”