Regional differences in endoscopic sinus surgery in Finland: a nationwide register-based study

Endoscopic sinus surgery (ESS) is a common operation typically performed due to chronic rhinosinusitis (CRS). There are limited data on the nationwide ESS rate and factors contributing to its regional variation. The aim was to evaluate factors causing variation of ESS rate.

Cross-sectional nationwide observational study.

A ll patients undergoing ESS in Finland 2013-2015.

Nationwide Finnish population aged 15 years or over.

ESS rate per 1000 inhabitants between 2013 and 2015 in all 21 hospital districts and independent factors for multilevel model analyses.

We used the Finnish register data of all patients with CRS who underwent ESS in 2013-2015. Patients aged under 15 years and those with ESS due to neoplasia were excluded. The age and gender standardised ESS rates were calculated, and multilevel Poisson regression models were used to evaluate variation in ESS in the 21 hospital districts. The likelihood ratio test was applied to assess the statistical significance of random components in the models.

The nationwide annual rate of ESS is 0.71 per 1000 people in Finland. Hospital district rates varied from 0.25/1000 (95% CI 0.18 to 0.32) to 1.15/1000 (95% CI 1.09 1.21). Compared with males, females undergo ESS significantly more frequently (57% of the procedures), more often due to CRS without nasal polyps, and at a younger age (mean age 44.2 and 46.2 years, correspondingly). Multilevel analyses showed that lower age (between 24 years and 45 years) and availability/ease of medical services were independently associated with higher ESS rates.

This study confirms marked regional variation in the ESS rate in Finland, explained only in part by patients' age and differing availability of medical services. To analyse ESS across different CRS phenotypes or to compare quality registers on ESS properly, more research on regional variation is needed.