Suboptimal prescribing of proton-pump inhibitors in low-dose aspirin users: a cohort study in primary care

OBJECTIVE: Determine the adherence to recommendations of concomitant proton-pump inhibitor (PPI) treatment in regular low-dose of aspirin (LDASA) users, taking factors associated with the probability of receiving a PPI into account. DESIGN: Cohort study. SETTING: Data were obtained from 120 Dutch primary care centres participating in the Netherlands Information Network of Primary Care (LINH). PARTICIPANTS: Patients 18 years and older who were regularly prescribed LDASA (30-325 mg) in 2008-2010 were included. MAIN OUTCOME MEASURES: Regular medication use was defined as receiving each consecutive prescription within 6 months after the previous one. Based on national guidelines, we categorised LDASA users into low and high gastrointestinal (GI) risk. A multilevel multivariable logistic regression analysis was applied to identify patient characteristics that influenced on the probability of regular PPI prescriptions. RESULTS: We identified 12 343 patients who started LDASA treatment, of whom 3213 (26%) were at increased risk of GI complications. In this group, concomitant regular use of PPI was 46%, 36% did not receive PPI prescriptions and 18% obtained prescriptions irregularly (p<0.0001). The chance to obtain regularly PPI prescriptions versus no PPI was significantly influenced by, among others, previous GI complications (OR 13.9 (95% CI 11.8 to 16.4)), use of non-steroidal anti-inflammatory drugs (OR 5.2 (4.3 to 6.3)), glucocorticosteroids (6.1 (4.6 to 8.0)), selective serotonin reuptake inhibitors (9.1 (6.7 to 12.2)), drugs for functional GI disorders (2.4 (1.9 to 3.0)) and increased age. CONCLUSIONS: Primary care physicians do not fully adhere to the current recommendations to prescribe PPIs regularly to LDASA users with an increased GI risk. More than 50% of the patients with an increased GI risk are not treated sufficiently with a concomitant PPI, increasing the risk of GI side effects. This finding underlines the necessity to consider merging recommendations into one common, standard and frequently used recommendation by primary care physicians.