Identification of rheumatoid arthritis in German claims data using different algorithms: Validation by cross‐sectional patient‐reported survey data

Abstract

Objective: To evaluate different algorithms for the identification of rheumatoid arthritis (RA) in claims data using patient-reported diagnosis as reference.Methods: Within longitudinal data from a large German statutory health insurance, we selected a random sample of persons with ICD-10 code for RA (M05/M06) in ≥2 quarters in 2013. The sample was stratified for age, sex, and M05/M06. Persons were asked to confirm RA diagnosis (gold standard), which was linked to claims data given consent. Analyses were weighted to represent the total RA population of the database. Positive predictive values (PPVs) and discriminative properties were calculated for different algorithms: ICD-10 code only, additional examination of inflammatory markers, prescription of specific medication, rheumatologist appointment, or combination of these.Results: Of 6193 persons with a claims diagnosis of RA, 3184 responded (51%).Overall, PPV for the ICD-10 code was 81% (95% confidence interval 79%-83%) with 94% (92%-95%) for M05 and 76% (73%-79%) for M06. PPVs increased (with loss of case numbers) if inflammatory markers (82% [80%-84%]), rheumatology visits (85% [82%-87%]) or specific medication (89% [87%-91%]) had been used in addition. Specific medication had the best discriminative properties (diagnostic odds ratio of 3.0) among persons with RA diagnosis. Conclusions:The ICD-10 codes M05 and (less optimal) M06 have high PPVs and are valuable to identify RA in German claims data. Depending on the respective research question, researchers should use different criteria for identification of RA.

Interstitial lung disease in rheumatoid arthritis: incidence, prevalence and related drug prescriptions between 2007 and 2020

“…Inpatient diagnostic procedures are not recorded as well. Seropositive RA may also be underestimated as ICD-10 coding in Germany is often unspecific 15. As women are over-represented in the BARMER statutory health insurance, but ILD is more common in men, this might lead to an underestimation of the number of persons with RA-ILD in this analysis.…”

“…To increase the specificity of the RA diagnosis, we additionally required a DMARD therapy, which could have been prescribed at any time point prior to or during the index year. Our previous validation of the RA ICD-10 diagnosis in the BARMER claims data revealed that the requirement of a prescribed DMARD significantly increases the specificity 15. To increase the specificity of ILD diagnosis, we additionally required the performance of a lung diagnostic test (function tests, chest radiographs, high-resolution CT (HRCT) scans, bronchoscopy or bronchoalveolar lavage).…”

High burden of polypharmacy and comorbidity in persons with psoriatic arthritis: an analysis of claims data, stratified by age and sex

“…The validity of PsA diagnoses has not been investigated in these data. For RA, 81% of the persons with two German modification of the International Statistical Classification of Diseases (ICD-10-GM) codes of M05 or M06 in a large survey confirmed the diagnosis and 7.2% had another inflammatory rheumatic disorder, predominately PsA 11…”

Systematisches Review zur Schätzung der Prävalenz entzündlich rheumatischer Erkrankungen in Deutschland

“…Die Prävalenz bei Grellmann et al ist niedriger als in den anderen Routinedatenanalysen, weil nur die spezifischen ICD-10-Codes für RA M05.8, M06.0 und M06.8 eingeschlossen wurden. In der Versorgungsrealität werden aber am häufigsten die unspezifischen RA ICD-10-Codes M06.9 und M05.9 verwendet [24], sodass bei dieser Arbeit von einer Untererfassung von RA-Fällen ausgegangen werden muss. Bei den Selbstangaben der Befragten aus der NAKO-Studie ist eine Übererfassung durch häufige Verwendung des Begriffs "Rheuma" auch bei Fingerpolyarthrose oder Gicht möglich; hier ist die Abgrenzung im Rahmen einer Befragung schwierig, obgleich explizit nach rheumatoider Arthritis bzw.…”