Does uptake of specialty care affect HRQoL development in COPD patients beneficially? A difference-in-difference analysis linking claims and survey data.

BACKGROUND: There is an evidence gap on whether the choice of specialty care beneficially affects health-related quality of life (HRQoL) in patients with chronic obstructive pulmonary disease (COPD). This study analyzes how newly initiated pulmonologist care affects the generic and disease-specific HRQoL in COPD patients over a period of 1 year. METHODS: We linked claims data with data from two survey waves to investigate the longitudinal effect of specialty care on HRQoL using linear Difference-in-Difference models based on 1:3 propensity score matched data. Generic HRQoL was operationalized by EQ-5D-5L visual analog scale (VAS), and disease-specific HRQoL by COPD assessment test (CAT). Subgroup analyses examined COPD patients with low (GOLD AB) and high (GOLD CD) exacerbation risk. RESULTS: In contrast to routine care patients, pulmonologists' patients (n = 442) experienced no significant deterioration in HRQoL (VAS - 0.0, p = 0.9870; CAT + 0.5, p = 0.0804). Models unveiled a small comparative advantage of specialty care on HRQoL (mean change: CAT - 0.8, VAS + 2.9), which was especially pronounced for GOLD AB (CAT - 0.7; VAS + 3.1). CONCLUSION: The uptake of pulmonologist care had a statistically significant, but not clinically relevant, beneficial impact on the development of HRQoL by slowing down overall HRQoL deterioration within 1 year. Including specialty care more appropriately in COPD management, especially at lower disease stages (GOLD AB), could thus improve patients' health outcome.

Impact of Lung Function and Exacerbations on Health-Related Quality of Life in COPD Patients Within One Year: Real-World Analysis Based on Claims Data.

PURPOSE: Real-world evidence on the impact of forced expiratory volume in one second (FEV1) and exacerbations on health-related quality of life (HRQoL) in patients with chronic obstructive pulmonary disease (COPD) is sparse especially with regard to GOLD ABCD groups. This study investigates how changes in FEV1 and exacerbations affect generic and disease-specific HRQoL in COPD patients over one year. METHODS: Using German claims data and survey data, we classified 3016 COPD patients and analyzed their health status by GOLD groups AB and CD. HRQoL was measured with the disease-specific COPD assessment test (CAT) and the visual analog scale (VAS) from the generic Euro-Qol 5D-5L. We applied change score models to assess associations between changes in FEV1 (≥100 mL decrease/no change/≥100 mL increase) or the development of severe exacerbations with change in HRQoL. RESULTS: FEV1 decrease was associated with a significant but not minimal important difference (MID) deterioration in disease-specific HRQoL (mean change [95% CI]: CAT +0.74 [0.15 to 1.33]), while no significant change was observed in the generic VAS. Experiencing at least one severe exacerbation also had a significant impact on CAT deterioration (+1.58 [0.52 to 2.64]), but again not on VAS. Here, GOLD groups AB showed not only a statistically but also a clinically relevant MID deterioration in CAT (+2.1 [0.88 to 3.32]). These particular patient groups were further characterized by a higher probability of being male, having a higher mMRC and Charlson index, and a lower probability of having higher FEV1 or BMI values. CONCLUSION: FEV1 decline and the occurrence of ≥1 severe exacerbation are significantly associated with overall deterioration in disease-specific HRQoL. Preventing severe exacerbations particularly in patients without previous severe exacerbations (ABCD groups A and B) may help to stabilize the key patient-reported outcome HRQoL.