Children's Acute Cough-Specific Quality of Life: Revalidation and Development of a Short Form.

PURPOSE: Acute cough in children has a significant impact on the child and family. Relevant quality of life (QoL) instruments are essential for high-quality clinical research. This study aimed to (1) revalidate the 16-item Parent-proxy Children's Acute Cough-specific QoL questionnaire (PAC-QoL16) using a different dataset (i.e., different children), (2) confirm the minimally important difference (MID), and (3) develop and validate a short form. METHODS: Three datasets from two sources were utilized, comprising of 332 children with acute cough (< 2 weeks duration); the first dataset (n = 83, 54 boys; median age 2.04 years, IQR 1.08-4.06 years) was used for revalidation, the second dataset (n = 238, 141 boys; median age 2.17 years, IQR 1.21-4.21 years) was used to develop the short form, and the third dataset (n = 94, 62 boys; median age, 1.75 years, IQR 0.90-3.63 years) was used to confirm the short form. Psychometric properties were investigated. RESULTS: Six items were found to account for 96.4% of the variance in the PAC-QoL16. The PAC-QoL16 and short form (PAC-QoL6) scales correlated with cough scores (rs ≤ - 0.40, p < 0.001), were internally consistent (Cronbach α = 0.94 and 0.87, respectively) and demonstrated sensitivity to change over time. A MID of 0.71 to 1.11 is recommended. CONCLUSION: Both the PAC-QoL16 and newly developed short form (PAC-QoL6) are reliable and valid outcome measures that assess children's acute cough-specific QoL at a given time point, are easy to interpret and reflect changes over time. The new short form addresses the need for outcome measures to be as time effective as possible without loss of information.