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Study highlights ‘nocebo’ effect with statins

Study highlights ‘nocebo’ effect with statins

Publication date: Tuesday, 30 May 2017
Contributor(s): Jeremy Bray

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Muscle-related symptoms are less commonly reported when patients and their doctors are unaware that statin therapy is being used, compared to when they are aware, according to a new studyon ASCOT-LLA trial data. This suggests that muscle pain and weakness are unlikely to be directly caused by statins, but may instead be due to the ‘nocebo’ effect, where the expectation of side-effects can make patients more likely to report them.

The first phase of the trial randomly assigned patients to receive atorvastatin 10mg or placebo and was double-blinded.  At the end of the 3 years the same patients were offered the choice of taking a statin or not in the non-blinded, non-randomised phase of the trial and these participants were followed for a further 2 years. 

During the blinded phase of the study, the rate of muscle-related symptoms was similar whether patients received a statin or placebo (2.03% per year vs 2% respectively). However, during the non-blinded phase of the study, muscle-related symptoms were 41% more common among people taking statins compared to those who weren’t (1.26% vs 1.00% per year respectively) (Table).
Professor Peter Sever (National Heart and Lung Institute, Imperial College London, UK) said,  “Just as the placebo effect can be very strong, so too can the nocebo effect. Patients can experience very real pain as a result of the nocebo effect and the expectation that drugs will cause harm. What our study shows is that it’s precisely the expectation of harm that is likely causing the increase in muscle pain and weakness, rather than the drugs themselves causing them.”


Blinded randomised phase

Non-blinded non-randomised phase




Atorvastatin non-user

Atorvastatin user

Adverse event rate





HR (95% CI), p


1.03 (0.88-1.21) 0.72


1.41 (1.10-1.79), 0.006

Table: Muscle related side effects in the two treatment phases.


Statins have a large database demonstrating their effectiveness and are suitable for many patients. It is important that GPs inform their patients to possible side-effects without raising negative expectations. They should also encourage their patients to understand the rationale for statin treatment, which will help shared decision making on this important lipid-lowering therapy.

Gupta A, Thompson D, Whitehouse A, et al. on behalf of the ASCOT investigators. Adverse events associated with unblinded, but not with blinded, statin therapy in the Anglo-Scandinavian Cardiac Outcomes Trial—Lipid-Lowering Arm (ASCOT-LLA): a randomised double-blind placebo-controlled trial and its non-randomised non-blind extension phase [published online May 2, 2017].

Lancet 2017

Topics covered:
Category: Evidence in Practice
Edition: Volume 2 Number 5 PCCJ Online 2017
Contributor(s): Jeremy Bray

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