Diverticular disease management in primary care: How do estimates from community-dispensed antibiotics inform provision of care?

BACKGROUND: The literature regarding diverticular disease of the intestines (DDI) almost entirely concerns hospital-based care; DDI managed in primary care settings is rarely addressed. AIM: To estimate how often DDI is managed in primary care, using antibiotics dispensing data. DESIGN AND SETTING: Hospitalisation records of New Zealand residents aged 30+ years during 2007–2016 were individually linked to databases of community-dispensed oral antibiotics. METHOD: Patients with an index hospital admission 2007–2016 including a DDI diagnosis (ICD-10-AM = K57) were grouped by acute/non-acute hospitalisation. We compared use of guideline-recommended oral antibiotics for the period 2007–2016 for these people with ten individually-matched non-DDI residents, taking the case’s index date. Multivariable negative binomial models were used to estimate rates of antibiotic use. RESULTS: From almost 3.5 million eligible residents, data were extracted for 51,059 index cases (20,880 acute, 30,179 non-acute) and 510,581 matched controls; mean follow-up = 8.9 years. Dispensing rates rose gradually over time among controls, from 47 per 100 person-years (/100py) prior to the index date, to 60/100py after 3 months. In comparison, dispensing was significantly higher for those with DDI: for those with acute DDI, rates were 84/100py prior to the index date, 325/100py near the index date, and 141/100py after 3 months, while for those with non-acute DDI 75/100py, 108/100py and 99/100py respectively. Following an acute DDI admission, community-dispensed antibiotics were dispensed at more than twice the rate of their non-DDI counterparts for years, and were elevated even before the index DDI hospitalisation. CONCLUSION: DDI patients experience high use of antibiotics. Evidence is needed that covers primary-care and informs self-management of recurrent, chronic or persistent DDI.