The Manchester cough in lung cancer scale: the development and preliminary validation of a new assessment tool

Context: Cough is a common distressing symptom in lung cancer patients. Its assessment is hampered by the lack of a validated scale to measure the complex cough experience in this population.

Objectives: To describe the development and preliminary validation of a scale to measure cough in lung cancer patients.

Methods: In the first phase, collection of qualitative data from patient interviews, a review of literature, and identification of noncancer cough scales resulted in the development of a pool of 30 items. This item pool was tested for appropriateness of content and breadth of coverage with 18 patients with lung cancer and 25 health care professionals. The second phase was the operationalization/phrasing of items. The final phase was the scale's field testing with 139 patients, 49 of whom repeated the assessment after one week.

Results: The first phase led to the deletion of several items and the addition of four, resulting in a final scale for field testing of 21 items. In the field testing, the scale was decreased to 10 items, eliminating items on psychometric grounds. The final scale's Cronbach alpha (internal consistency) was 0.86, item to total correlations ranged from 0.40 to 0.76, and test-retest reliability was high (intraclass correlation=0.83).

Conclusion: We have developed a promising tool to assess cough in lung cancer, but this needs validation, and future studies should determine whether this is a sensitive and responsive tool. A fully validated tool can be used in the clinical assessment of cough in cancer patients, and as a unidimensional impact scale in the measurement of cough as an outcome in intervention studies.