Clinical relevance of alerts from a decision support system, PHARAO, for drug safety assessment in the older adults

BackgroundPHARAO is a decision support system developed to evaluate the risk for a set of either common or serious side-effects resulting from a combination of pharmacodynamic effects from a patients medications. The objective of this study was to investigate the validity of the risk scores for the common side-effects generated by PHARAO in older patients.MethodsSide-effects included were sedation, constipation, orthostatic symptoms, anticholinergic and serotonergic effects. The alerts generated by PHARAO were tested in 745 persons 65years old. Dispensed prescriptions retrieved from the Swedish prescribed drug register were used to generate the pharmacological risk scores of patients medications. Symptoms possibly related to side-effects were extracted from medical records data.ResultsThe PHARAO system generated 776 alerts, most often for the risk of anticholinergic symptoms. The total specificity estimates of the PHARAO system were 0.95, 0.89 and 0.78 for high, intermediate and low risk alerts, respectively. The corresponding sensitivity estimates were between 0.12 and 0.37. The negative predictive value was 0.90 and the positive predictive value ranged between 0.20-0.25.ConclusionsThe PHARAO system had a high specificity and negative predictive value to detect symptoms possibly associated with the of patients medications, while the sensitivity and positive predictive value were low. The PHARAO system has the potential to minimise the risk of over-alerts in combination with a drug-drug interaction alert system, but should be used in connection with a medical evaluation of the patient.
Funding Agencies|National Corporation of Swedish Pharmacies (Apoteket AB); Linkoping university; Region Ostergotland; Region Vastra Gotaland