Validation of claims‐based algorithms for psoriatic arthritis

Abstract

Purpose: An increasing number of new medications are being developed and approved for psoriatic arthritis (PsA). To generate real-world evidence on comparative safety and effectiveness of these drugs, a claims-based algorithm that can accurately identify PsA is greatly needed.Methods: To identify patients with PsA, we developed seven claims-based algorithms based on a combination of diagnosis codes and medication dispensing using the claims data from Medicare parts A/B/D linked to electronic medical records (2012)(2013)(2014). Two physicians independently conducted a chart review using the treating physician's diagnosis of PsA as the gold standard. We calculated the positive predictive value (PPV) and 95% confidence intervals of each algorithm.Results: Of the total 2157 records identified by the seven algorithms, 45% of the records had relevant clinical data to determine the presence of PsA. The PPV of the algorithms ranged from 75.2% (algorithm 1: ≥2 diagnosis codes for PsA and ≥1 diagnosis code for psoriasis) to 88.6% (algorithm 7: ≥2 diagnosis codes for PsA with ≥1 code by rheumatologist and ≥1 dispensing for PsA medication). Having ≥2 diagnosis codes and ≥1 dispensing for PsA medications (algorithm 6) also had PPV of 82.4%.Conclusions: All seven claims-based algorithms demonstrated a moderately high PPV of 75% to 89% in identifying PsA. The use of ≥2 diagnosis codes plus ≥1 prescription claim for PsA appears to be a valid and efficient tool in identifying PsA patients in the claims data, while broader algorithms based on diagnoses without a prescription claim also have reasonably good PPVs. K E Y W O R D S claims database, Medicare, pharmacoepidemiology, psoriasis, psoriatic arthritis

Risk of Hospitalization for Serious Infection After Initiation of Ustekinumab or Other Biologics in Patients With Psoriasis or Psoriatic Arthritis

“…Patients were required to have ≥2 inpatient or outpatient International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) or Tenth Revision (ICD-10) diagnosis codes of PsO or ≥2 inpatient or outpatient ICD-9-CM/ ICD-10-CM diagnosis codes of PsA during the 6-month baseline period. These definitions were modified versions of claims-based definitions, which had positive predictive values of 75.3% and 75.2% for PsO and PsA, respectively (13). Patients eligible for study entry were required to be ≥18 years old on the index date and continuously enrolled in an insurance program included in the claims databases for ≥6 months prior to the index date.…”

Occurrence of inflammatory bowel disease in patients with chronic inflammatory skin diseases: a cohort study

“…Requiring that individuals with and without CISD were seen by a specialist at least twice before cohort entry reduces differential surveillance bias 14 . Patients with psoriatic arthritis, defined as a diagnosis of psoriatic arthritis by a dermatologist and by a rheumatologist, were not analysed as an individual group, as it was too small (< 1500) 15 …”

“…14 Patients with psoriatic arthritis, defined as a diagnosis of psoriatic arthritis by a dermatologist and by a rheumatologist, were not analysed as an individual group, as it was too small (< 1500). 15 The patients without CISD were matched on the cohort entry date of the patients with CISD, AE 60 days, and were required to have at least 365 days of continuous enrolment before the matched cohort entry date. Patients were allowed to contribute only once to the study.…”

Patient characteristics associated with use of TNF vs interleukin inhibitors as first-line biologic treatment for psoriatic arthritis

“…The claims-based algorithm, which combined at least 2 diagnosis codes for PsA and at least 1 dispensing for PsA treatment, had a positive predictive value of 82.4% for identifying patients with PsA. 21 The index date was defined as the date of the first dispensing of TNF inhibitors or IL-12/23 or 17 inhibitors with no previous use of biologics. Eligible patients were required to be aged at least 18 years on the index date and have a 1-year continuous enrollment before and after the index date (Supplementary Figure 1, available in online article).…”