GOLD severity stratification and risk of hospitalisation for COPD exacerbations

The Italian Costs for Exacerbations in COPD ("ICE") study, following a pharmacoeconomic assessment of costs due to COPD exacerbations (primary endpoint), aimed also at evaluating (secondary endpoint) which clinical factors, among those considered for cost-analysis, may, at follow up, present a risk of new exacerbations and re-admission to hospital.

A prospective, multicentre study was carried out on COPD patients admitted to 25 Hospital Centres as a result of an exacerbation from October-December 2002. Following discharge, a 6-month follow-up was performed in each patient via three bi-monthly telephone interviews with a questionnaire administered by an investigator clinician.

570 patients were eligible for data processing, mean age 70.6 years (+/- 9.5 standard deviation, SD), males 69.2%. According to GOLD, severity stratification was as follows: moderate 36.4%; severe 31.3%; very severe 32.3%. 282 patients experienced at least one exacerbation at follow up, 42% of exacerbations requiring hospitalisation. No significant association was seen between exacerbations and GOLD stage or co-morbidities or treatments except LTOT. Conversely, COPD functional severity influenced hospitalisations very significantly, with relative risks 2.6 (95% Confidence Interval, CI 1.8-3.8) and 2.0 (CI 1.3-2.8) (GOLD very severe versus moderate and severe, respectively), and 1.3 (CI 0.85-2.1) (GOLD severe versus moderate). Hospitalisations were also significantly associated with treatments denoting more severe conditions (oral corticosteroids, oral theophylline, and LTOT).

Severity stratification of COPD patients according to respiratory function classes as outlined in GOLD guidelines and need for LTOT are confirmed as important predictors of hospitalisation for an exacerbation.