Case finding for chronic obstructive pulmonary disease in primary care: a pilot randomised controlled trial

Background

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality. However, much of the disease burden remains undiagnosed.

Aim

To compare the yield and cost effectiveness of two COPD case-finding approaches in primary care.

Design and setting

Pilot randomised controlled trial in two general practices in the West Midlands, UK.

Method

A total of 1634 ever-smokers aged 35–79 years with no history of COPD or asthma were randomised into either a ‘targeted’ or ‘opportunistic’ case-finding arm. Respiratory questionnaires were posted to patients in the ‘targeted’ arm and provided to patients in the ‘opportunistic’ arm at routine GP appointments. Those reporting at least one chronic respiratory symptom were invited for spirometry. COPD was defined as pre-bronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC)<0.7 and FEV1<80% of predicted. Primary outcomes were the difference in the proportion of patients diagnosed with COPD and the cost per case detected.

Results

Twenty-six per cent (212/815) in the ‘targeted’ and 13.6% (111/819) in the ‘opportunistic’ arm responded to the questionnaire and 78.3% (166/212) and 73.0% (81/111), respectively, reported symptoms; 1.2% (10/815) and 0.7% (6/819) of patients in the ‘targeted’ and ‘opportunistic’ arms were diagnosed with COPD (difference in proportions = 0.5% [95% confidence interval {CI} = –0.5% to 3.08%]). Over a 12-month period, the ‘opportunistic’ case-finding yield could be improved to 1.95% (95% CI = 1.0% to 2.9%). The cost-per case detected was £424.56 in the ‘targeted’ and £242.20 in the ‘opportunistic’ arm.

Conclusion

Opportunistic case finding may be more effective and cost effective than targeting patients with a postal questionnaire alone. A larger randomised controlled trial with adequate sample size is required to test this.