Updated: May 31, 2021
Authors: Herrett E, Williamson E, Brack K, Beaumont D, Perkins A, Thayne A et al.
A recent BMJ article demonstrated the value of N-of-1 trials for exploring side effects of statins, a drug taken by millions of people worldwide for the primary and secondary prevention of cardiovascular events. Despite their effectiveness in reducing the risk of cardiovascular events such as heart attacks and strokes, there have been many reports of patients discontinuing statins after they start taking them because of intolerable muscle pain that they believe to be a side effect. In this study by Herrett et al (2021), the authors used a series of N-of-1 trials to answer the question: are statins associated with muscle pain and weakness? Participants were patients recruited through 50 general practices in the UK. Two-hundred participants agreed to take part in a 12-month N-of-1 trial. Specifically, the trial design involved six 2-monthly treatment periods; during 3 of these treatment periods participants would take statin (20mg Atorvastatin) and during the other 3 treatment periods they would take placebo. The order of treatment periods was randomly determined using block randomisation (i.e., randomisation of treatment pairs of statin and placebo). Participants recorded their muscle symptoms using a visual analogue scale on a daily basis throughout the trial. At the end of the study, sufficient data was available for 151 participants. The aggregated analysis of the data showed that there was no statistically significant difference in the frequency or severity of muscle symptoms between statin and placebo periods. After receiving their personalised trial results, 2 in every 3 participants resumed statins. These findings help to reduce the uncertainty surrounding statins and their side effects and may, in turn, lead to a substantial benefit for patients and healthcare systems.
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Full Citation: Herrett E, Williamson E, Brack K, Beaumont D, Perkins A, Thayne A et al. Statin treatment and muscle symptoms: series of randomised, placebo controlled n-of-1 trials BMJ2021; 372: n135