gms | German Medical Science

Background and status of (inter)national research: Chronic kidney disease (CKD) is common in both men and women and is mainly found in the elderly. Gender differences with regards to etiology, epidemiology and progression of CKD have been previously identified in large cohort studies. In contrast to other European countries, there is a lack of CKD cohorts in Germany and therefore, data on CKD incidence and potential differences between men and women is sparse.

Question and objective:The aim of this study was to estimate the incidence of CKD (stages 2–5) in men and women based on health insurance data. Additionally, we aimed at identifying potential differences between men and women with CKD in terms of any pre-existing diseases and the use of health care services.

Method or hypothesis: This cohort study used claims data from a regional statutory health insurance fund (Allgemeine Ortskrankenkasse (AOK) Baden-Württemberg) from both outpatient and inpatient care. The study population comprised all members of the statutory health insurance fund, who were 18 years of age or older and who had an incident CKD diagnosis between 2011 and 2018. An incident CKD diagnosis was recorded if either two outpatient diagnoses in two separate quarters of one year (M2Q) or one inpatient diagnosis were coded. Members of the statutory health insurance fund with a previous CKD diagnosis or with any kidney replacement therapy within two years prior to the incident diagnosis were excluded. Incidence of CKD in both genders was standardized to the German standard population of 2011.

Results: The final study population comprised 282.836 men and women with incident CKD between 2011 and 2018. Women were significantly older than men at the time of the first CKD diagnosis (78.2 vs.74.0 years) and made up 56% of the study population. Age-standardized incidence of CKD stages 2 and 3 was higher in men (378/100.000 and 607/100.000) than in women (284/100.000 and 499/100.000) while in CKD stages 4 and 5 the incidence was similar in men (80/100.000 and 19/100.000) and women (73/100.000 and 11/100.000). Statistically significant differences between both genders were found for almost all pre-existing diseases. In regards of the use of health care services, men were generally more likely to visit a nephrologist in the years after the incident diagnosis and were more often hospitalized in the first year after the incident CKD diagnosis compared to women.

Discussion: Our analyses suggest gender-related differences in the incidence of CKD, pre-existing diagnoses and the use of health care services. However, the interpretation of these findings has to take known limitations of claims data into account.

Practical implications: Gender-sensitive analyses can contribute to a better understanding of CKD and can raise awareness for the need to monitor a declining renal function more closely in the elderly, especially in women.

Appeal for practice (science and/or care) in one sentence: Based on the knowledge gained from our analyses, further prospective gender-related research projects in CKD should be conducted.