Registered incidence of acute upper respiratory tract infections diagnosed by primary care physicians in Poland - 5-year retrospective analysis of the national health insurance database.

Introduction and objective: Upper respiratory tract infection (URTIs), caused by a variety of viruses and sometimes by bacteria, represents the most common acute illness in primary health care. The aim of the study was to explore the registered incidence of URTIs in Poland in the period between 2015-2019, and its burden on the health care system.

Material and methods: A retrospective analysis was carried out of all medical encounters in Poland registered within the national billing database of public healthcare services. Medical services provided due to acute URTIs were classified according to the ICD-10 codes. Registered Incidence Rate (RIR) was calculated yearly, in a 100,000 population. A generalised additive model was used to calculate the Incidence Rate Ratio (IRR).

Results: In the analysed 5-year period, acute URTI was diagnosed in 24.3 million patients (61.7% of the whole population registered in PHC). The RIR of all acute URTIs in PHC was 50,762/100,000/year. Nearly 99% of consultations in this group of patients were provided by PHC physicians. Only 0.8% were referred to an OSC consultation and 0.4% were hospitalised. In PHC, indeterminate URTIs were most frequently diagnosed. The estimated IRR for children aged 1-4 years was 1.65 (95% CI: 1.64; 1.66, p<0.01) and for men 0.79 (95% CI: 0.79; 0.79; p<0.01). In the studied period, the number of patients consulted for acute URTI decreased slightly in PHC, but significantly in specialist services.

Conclusions: The registered incidence of URTIs in Poland burdens mainly PHC physicians. Women and children aged 1-4 years are more frequent users of medical services related to URTIs. It appears that strategies for increasing patient empowerment to provide efficient self-care reducing the utilisation of PHC services are needed.