Seven studies were included. Three comparative studies represented the focus of the review, and appeared generally to be at low risk of bias (one UK study, one Danish study and one study conducted in the Netherlands). A total of 8,475 reactions were reported by patients, and 38,891 by healthcare professionals.
Statins and proton pump inhibitors were the most commonly reported drugs causing adverse reactions (two studies). The most frequent types of adverse drug reaction were psychiatric or nervous system disorders, and infections and infestations (two studies).
In the UK study, odds ratios (presented according to System Organ Class) suggested that eleven adverse reactions were significantly more likely to be reported by patients than healthcare professionals; one was more likely to be reported by healthcare professionals (cardiac disorders: OR 0.76, 99% CI 0.61 to 0.95); and two showed similar rates of reporting between patients and professionals.
In the Danish study, psychiatric and nervous system disorders were significantly more likely to be reported by patients; investigations, infections and infestations were more likely to be reported by healthcare professionals; and the remaining outcomes were reported similarly by patients and healthcare professionals. Symptoms of adverse drug reaction reported by patients and healthcare professionals included nausea, headache, rash , and dizziness (two studies). Six symptoms were reported to varying degrees by professionals and patients.
Across three studies (UK, Denmark and the Netherlands studies), the seriousness and number of adverse drug reactions reported by patients and healthcare professionals differed. One study reported a statistically significant difference between patients and healthcare professionals (p<0.0001), while two studies showed similar reports between the groups. The number of serious adverse drug reactions as a percentage of total reports was similar for patients and healthcare professionals within the studies.