Novel tool developed to assess, monitor cough
Researchers have recently developed and validated the effectiveness of Cough Assessment Test (COAT), a simple questionnaire used to evaluate and monitor cough.
This study sought to create a short patient-completed questionnaire, which was developed through reliability test and validated in comparison with the Korean version of Leicester Cough Questionnaire (K-LCQ) and cough numeric rating scale (NRS, 0–10; 11-point scale) for chronic cough patients.
A selection process identified five items about cough frequency, daily activity, sleep disturbance, fatigue and cough hypersensitivity (0–4 scaling of the items, 0–20 score range) to develop COAT, which was then tried in a reliability test cohort (n=78).
Internal consistency was excellent (Cronbach’s a, 0.84), and test retest repeatability was very good (intraclass correlation coefficient, 0.88). The final COAT was compared with K-LCQ and cough NRS in a validation cohort (n=323).
Rasch analysis revealed that COAT fitted well to a unidimensional model. Pearson correlations were –0.71 for COAT vs K-LCQ before treatment and –0.81 after treatment, 0.69 for COAT vs cough NRS before treatment and –0.82 after treatment, –0.66 for delta-COAT vs delta-cough NRS, and 0.72 for delta-COAT vs delta-K-LCQ.
“A cough‐specific quality‐of‐life questionnaire is recommended to assess the impact of cough,” the investigators said. “[H]owever, a simple instrument to quantify cough is required for everyday clinical practice.”
A previous systematic review and meta-analysis found that several instruments for assessing cough severity, frequency and impact on quality of life demonstrate good internal consistency but variable correlation with other cough measurement tools. This means that while some instruments are precise, their accuracy is less clear. [AHRQ Comparative Effectiveness Reviews 2013;Report No:13-EHC032-EF]