[Calculation of morbidity, use of resources and costs of patients treated with tiotropium bromide for COPD in a Spanish population].

Objective: To determine the co-morbidity and economic impact of treatment with tiotropium bromide (TB) for COPD, in a population cared for by Spanish primary care teams (PCTs) and specialist physicians, in the context of routine clinical practice.

Design: Retrospective multi-centre study.

Setting: Four PCTs and 2 urban hospitals.

Participants: Patients with COPD receiving regular treatment with TB, during 2004.

Main Measurements: Age and sex, episodes of co-morbidity, clinical parameters, resource use, and pharmacological groups. The costs model was established by differentiating semi-fixed from variable costs (pharmacy, tests, referrals) in the PCTs, as well as the visits, emergencies and hospital admissions occurring in the hospitals. A logistical regression analysis was made to correct the model. The costs were contrasted by analysis of covariance (ANCOVA), with the estimation of marginal means (Bonferroni adjustment).

Results: Of 900 patients with COPD, 14.3% (n=129) received treatment with TB (95% CI, 12.0%-16.6%). The mean episodes/patient/year was 2.1 (1.4) versus 1.8 (1.3) (NS), seriousness/severity 41.3% versus 26.3% (P =.001), defined daily dose (DDD) 5928.5 (9624.1) versus 6187.7 (12471.3) (NS) and number visits/patient/year 15.1 (9.4) versus 17.3(11.9) (P=.044). After adjustments for age and sex, TB use was associated with Diabetes Mellitus (OR=1.6; 95% CI, 1.0-2.5; P=.034) and severity of patients' illness (OR=1.8; 95% CI, 1.2-2.8; P=.004). Quantification of unit cost/year was 2793.16 (3166.30) euros (3359.27 [3423.25] euros versus 2703.09 [3113.75] euros; P=.001). The adjusted patient cost/year was 2831.23 euros (SE, 217.32) with TB versus 2786.86 euros (SE, 88.53) without TB (NS).

Conclusions: TB is associated, as therapy complementing routine treatment, with the presence of Diabetes, and with the severity of the disease. The costs of COPD entail high resource consumption. The prescription of TB does not imply greater overall cost of the disease.