The Incidence of Proximal Humerus Fracture

An Analysis of Insurance Data

Proximal humerus fracture (PHF) is the third most common age-related fracture in the elderly, with women more frequently affected than men [1–4]. Currently only incomplete and inconclusive data are available on the actual incidence of PHF, describing preselected cohorts with observed incidences ranging from 60.1 to 90.8 per 100 000/person-years [1–3]. These studies were often based on small sample sizes or included only inpatient cases. However, conservatively treated patients, in particular, are rarely hospitalized and are therefore frequently not included in such studies. The aim of the study described here, based on a large healthcare-related database, was to evaluate the incidence of PHF not only in inpatients but also in outpatients, in order to enable to estimation of the actual fracture incidence and the resulting treatment and aftercare requirements.

Methods

The incidence of PHF was determined on the basis of retrospective inpatient and outpatient data from the BARMER health insurance company, standardized for age and sex according to the German population. The BARMER company is one of the largest statutory health insurance funds in Germany with more than 8 million members. The study included all inpatient and outpatient cases coded for PHF (ICD S42.2) in the period 2011–2021. To avoid double counting due to secondary hospitalizations, only one case per patient per 3 years was considered. The standardized cohort was a random sample drawn in such a way that the mean age and the proportion of women were the same as in the German population.

Results

During the observation period, the 1-year incidence of PHF per 100 000 population increased from 104.1 in 2011 to 110.0 in 2021. On average (mean ± standard deviation), the incidence of PHF per 100 000 population/year was 110.0 (± 2.7) and thus 1.7 times higher than the incidence for inpatient cases alone (Table). Among elderly patients (age ≥ 65 years), women were markedly more often affected by PHF than men (76% were women; Table). Interestingly, analysis of age-related incidence by decade showed higher incidences for men than for women in younger adults (age < 50 years) (Figure).

Figure

Incidence of proximal humerus fracture with Clopper–Pearson 95% confidence interval by age (in decades), determined using inpatient and outpatient data from the BARMER health insurance fund

Table

Incidence of proximal humerus fracture, determined using patient and outpatient data

Discussion

The results presented here indicate that the true fracture incidence is considerably underestimated when only inpatient data are analyzed. Although the data including only the inpatient sector are almost consistent with previous findings as reported in the literature (1, 2, 3) and with the nationwide InEK data (InEK, Institut für das Entgeltsystem im Krankenhaus [Institute for the Hospital Remuneration System]; https://datenbrowser.inek.org/), they have the same drawback of not examining the entire outpatient sector. Moreover, the nationwide data of the InEK and the earlier study by Rupp et al. [3] were based on case-related data: this made allocation to the individual person impossible, so secondary hospitalizations were included. In the BARMER database each patient can be identified, enabling longitudinal observation of the patients and elimination of double counting.

When outpatient data are taken into account, the true extent becomes apparent: the actual incidence of PHF per 100 000 person-years is 1.7 times higher than previously assumed. Furthermore, more than one fourth of all patients require secondary hospitalizations within 3 years (e.g., for treatment of complications or revision surgery), so the actual need for treatment and care of PHF is even greater.

Because women suffer fragility fractures more often than men, the rate of PHF per 100 000/year is higher than for ischemic stroke or acute myocardial infarction (5). The presented incidences are of particular relevance, as they demand a new evaluation of the burden of disease. With regard to non-surgically treated PHF, in particular, there is little information about complications, loss of autonomy, and changes in geriatric care.

As a limitation of this study, it should be noted that the BARMER health insurance fund cohort had a slightly greater proportion of women and a higher average age than the national population. To prevent bias, however, the cohort was age- and sex-standardized to the German population on the basis of data from the Federal Statistical Office. Moreover, to avoid double coding only cases occurring 3 years apart were evaluated. Two consecutive fractures occurring within a shorter period were not counted, so the incidence may still be underestimated.

In the light of demographic changes, all osteoporosis-related fractures represent a growing challenge for the healthcare system in Germany (and elsewhere). Further research is required focusing on reduction of complications and mortality and optimization of functional outcomes. Our data show that the outpatient sector currently seems to represent an unexplored area that must be made the focus of future research.

Jeanette Koeppe, Josef Stolberg-Stolberg, Karen Fischhuber, Janette Iking, Ursula Marschall, Michael J. Raschke, J. Christoph Katthagen

Ethics approval

The study was conducted in accordance with the Declaration of Helsinki and was approved by the Ethics Committee of Westfalen–Lippe (no. 2022–300-f-S). Because the insurance data were anonymized, no prior written informed consent had to be obtained from the patients.

Funding

This work received support from the program Innovative Medical Research (Innovative Medizinische Forschung) (grant number I-KÖ122113) of the Faculty of Medicine, University of Münster.

Conflict of interest statement
The authors declare that no conflict of interest exists.

Manuscript submitted on 14 February 2023, revised version accepted on 17 May 2023

Cite this as:
Koeppe J, Stolberg-Stolberg J, Fischhuber K, Iking J, Marschall U, Raschke MJ, Katthagen JC: The incidence of proximal humerus fracture—an analysis of insurance data.

Dtsch Arztebl Int 2023; 120: 555–6. DOI: 10.3238/arztebl.m2023.0132

References

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4. Stolberg-Stolberg J, Köppe J, Rischen R, et al.: The surgical treatment of proximal humeral fractures in elderly patients—an analysis of the long-term course of locked plate fixation and reverse total shoulder arthroplasty based on health insurance data. Dtsch Arztebl Int 2021; 118: 817–23

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