Performance of a brief asthma control screening tool in community pharmacy: a cross-sectional and prospective longitudinal analysis.

Background: Guidelines recommend basing asthma management on assessment of asthma control. Validated control tools, while suitable for clinical research, may not be feasible for routine use in primary care.

Aims: To describe the performance of the Pharmacy Asthma Control Screening tool (PACS) compared with the Asthma Control Questionnaire (ACQ-6).

Methods: Data were obtained from a multicentre study of a community pharmacy asthma management programme in Australia, with three or four visits over six months. Eligible participants had suboptimal asthma control or no recent visit to their doctor for asthma. Asthma control was assessed at baseline and at six months with the PACS tool and ACQ-6.

Results: A total of 570 patients were enrolled and 398 (70%) completed the programme. The average ACQ-6 score was 1.58±1.05 at baseline and 0.96±0.88 (n=392) after six months. Sensitivity and specificity of PACS 'poor control' for not well-controlled asthma (ACQ- 6 >1.0) were 0.92 and 0.66, respectively, at baseline and 0.76 and 0.83 at six months. Agreement between the two tools at six months was moderate (κ=0.54). Both tools showed highly significant change during the study (p<0.0001 for each), but agreement between the change in the two tools was only fair (κ=0.31).

Conclusions: This study shows that a simple asthma control screening tool is feasible for use in community pharmacies and has good sensitivity for identifying patients with not well-controlled asthma. Screening tools are useful in primary care to identify patients who require more detailed assessment of their asthma status, whereas for monitoring asthma control over time, a continuous control measure is more appropriate.