Health status in the TORCH study of COPD: treatment efficacy and other determinants of change

Background

Little is known about factors that determine health status decline in clinical trials of COPD.

Objectives

To examine health status changes over 3 years in the TORCH study of salmeterol+fluticasone propionate (SFC) vs. salmeterol alone, fluticasone propionate alone or placebo.

Methods

St George''s Respiratory Questionnaire (SGRQ) was administered at baseline then every 6 months.

Measurements and Main Results

Data from 4951 patients in 28 countries were available. SFC produced significant improvements over placebo in all three SGRQ domains during the study: (Symptoms -3.6 95% CI -4.8, -2.4], Activity -2.8 95% CI -3.9, -1.6], Impacts -3.2 95% CI -4.3, -2.1]) but the pattern of change over time differed between domains. SGRQ deteriorated faster in patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages III & IV relative to GOLD stage II (p < 0.001). There was no difference in the relationship between deterioration in SGRQ Total score and forced expiratory volume in one second (FEV₁) decline (as % predicted) in men and women. Significantly faster deterioration in Total score relative to FEV₁ % predicted was seen in older patients (≥ 65 years) and there was an age-related change in Total score that was independent of change in FEV₁. The relationship between deterioration in FEV₁ and SGRQ did not differ in different world regions, but patients in Asia-Pacific showed a large improvement in score that was unrelated to FEV₁ change.

Conclusions

In addition to treatment effects, health status changes in clinical trials may be influenced by demographic and disease-related factors. Deterioration in health status appears to be fastest in older persons and those with severe airflow limitation.

Trial Registration

ClinicalTrials.gov: {"type":"clinical-trial","attrs":{"text":"NCT00268216","term_id":"NCT00268216"}}NCT00268216