Sociodemographic factors and uncomplicated pyelonephritis in women aged 15-50 years: a nationwide Swedish cohort register study (1997-2018)

Abstract

Objective: To study the relationship between sociodemographic factors and pyelonephritis.

Methods: A nationwide open cohort study consisting of 2,052,873 women (76.2% Swedish-born) aged 15-50 years was conducted (1997-2018). The outcome was the first event of acute uncomplicated pyelonephritis diagnosed in primary healthcare settings in relation to the sociodemographic factors. Cox regression models were used in the analyses.

Results: The study identified 40,724 cases. In the fully adjusted model, women from non-Western countries had a higher risk of pyelonephritis compared to Swedish-born women. Women from Latin America/the Caribbean had the highest risk (Hazard ratio = 1.60; 95% CI 1.49-1.72), followed by Eastern Europe (HR = 1.26; 95% CI 1.21-1.32) and the Middle East/North Africa (HR = 1.25; 95% CI 1.19-1.30). Low education, low income, urban living, and young age were also associated with higher risks of pyelonephritis.

Conclusion: This study presents novel risk factors associated with pyelonephritis. Women from non-Western countries and with low socioeconomic status might disproportionately suffer from this serious infection. This might be due to biological predispositions and the fact that immigrant women do not acquire the same level of health or might receive less healthcare compared to native women, even in the presence of universal healthcare.

Keywords: Country of birth; Education; Parities; Pyelonephritis; Sociodemographic; Socioeconomic.