A review of nearly 80 randomised trials has found pharmacist services for patients in the community had varying effects on outcomes compared with usual care

A Cochrane systematic review has looked at 116 trials, comprising 111 trials (39,729 participants) comparing pharmacist interventions with usual care and five trials (2122 participants) comparing pharmacist services with services from other healthcare professionals.

Of these, 76 were included in meta‐analyses. The 40 remaining trials were not included in the meta‐analyses because they each reported unique outcome measures which could not be combined.

Most of the trials targeted chronic conditions and were conducted in a range of settings, mostly community pharmacies and hospital outpatient clinics.

The authors looked at pharmacist services for a wide range of conditions including high blood pressure and diabetes, measuring their effect on benefits (improved health outcomes) as well as harms (unplanned hospital admissions, adverse drug effects).

Most trials had a low risk of reporting bias and about 25%‐30% were at high risk of bias for performance, detection, and attrition.

Selection bias was unclear for about half of the included studies.

Compared with usual care, the researchers were “uncertain” on whether pharmacist services reduced the percentage of patients outside the glycated haemoglobin target range (5 trials, n = 558, odds ratio (OR) 0.29, 95% confidence interval (CI) 0.04 to 2.22).

Evidence was described as “very low‐certainty”, meaning the authors had very little confidence in the effect estimate, with the true effect likely to be substantially different from the estimate of effect.

Pharmacist services may reduce the percentage of patients whose blood pressure is outside the target range (18 trials, n = 4107, OR 0.40, 95% CI 0.29 to 0.55), but this was based on low‐certainty evidence.

Pharmacist services may probably lead to little or no difference in hospital attendance or admissions (14 trials, N = 3631, OR 0.85, 95% CI 0.65 to 1.11), the Cochrane authors concluded based on moderate‐certainty evidence.

Pharmacist services may make little or no difference to adverse drug effects (3 trials, n = 590, OR 1.65, 95% CI 0.84 to 3.24) and may slightly improve physical functioning (7 trials, n = 1329, mean difference (MD) 5.84, 95% CI 1.21 to 10.48; low‐certainty evidence).

Pharmacist services may make little or no difference to mortality (9 trials, n = 1980, OR 0.79, 95% CI 0.56 to 1.12, low‐certainty evidence).

Of the five studies that compared services delivered by pharmacists with other health professionals, none evaluated the impact of the intervention on the percentage of patients outside blood pressure or glycated haemoglobin target range, hospital attendance and admission, adverse drug effects, or physical functioning.

The results demonstrate that pharmacist services have varying effects on patient outcomes compared with usual care, say the authors.

“We found no studies comparing services delivered by pharmacists with other healthcare professionals that evaluated the impact of the intervention on the six main outcome measures,” they wrote in the Cochrane Database of Systematic Reviews.

“The results need to be interpreted cautiously because there was major heterogeneity in study populations, types of interventions delivered and reported outcomes.

“There was considerable heterogeneity within many of the meta‐analyses, as well as considerable variation in the risks of bias.”

The Cochrane review authors say their results generally concur with those of other reviews of pharmacist services conducted in different settings or with different health conditions or patient populations, which report mixed evidence of the benefit of pharmacy interventions (Altowaijri 2013Charrois 2012Greer 2016Hatah 2014Jokanovic 2017Koshman 2008Mekonnen 2016Pande 2013Walsh 2016).

An earlier Cochrane Review (Glynn 2010) of interventions to improve hypertension suggested that pharmacist‐led interventions showed promising results.

Meanwhile a recent narrative review published in the Journal of Pharmaceutical Policy and Practice, found pharmacists’ interventions have led to improved asthma control, detection of diabetes and cardiovascular risk factors, reduction in smoking rates and weight, and identification of drug-related problems.