Uptake of cystic fibrosis testing in primary care: supply push or demand pull?

Abstract

Objective: To determine the acceptability and feasibility of screening for carriers of cystic fibrosis in a primary care setting.

Design: Follow up study over 15 months of patients offered carrier testing by mouthwash.

Setting: A general practice in inner London.

Subjects: 5529 patients aged 18-45 invited by various methods and combinations of methods (letter, booklet, personal approach) for testing.

Main outcome measures: Uptake of screening, anxiety, and knowledge of test.

Results: 957 (17%) invitees were screened over the 15 months. 28 carriers and no carrier couples were detected. Uptake rates were 12% (59/502 patients) among patients invited by letter and tested by appointment; 9% (47/496) among patients invited by letter, with leaflet, and tested by appointment; 4% (128/2953) among patients invited by letter six weeks before the end of the study and tested by appointment; 17% (81/471) among patients offered passive opportunistic testing; 70% (453/649) among patients offered active opportunistic testing; and 25% (22/88) among patients offered active opportunistic testing by appointment. A short term rise in anxiety among those given a positive test result had dissipated by three months. At three months about one fifth and one third of those given positive and negative results respectively did not understand their results correctly.

Conclusion: These results suggest that the strongest variable in determining uptake of screening is the active approach by a health professional offering immediate testing. It remains to be resolved whether the high uptake rates achieved by active recruitment indicate a supply push for this new test rather than a demand from the population.