New measure of health-related quality of life for patients with oropharyngeal mucositis: development and preliminary psychometric evaluation.
BACKGROUND
Oropharyngeal mucositis (OM) causes profound impairment of patients' health-related quality of life (HQoL). The aim of the article is to describe the development and preliminary validation of an HQoL instrument, OMQoL, specifically for patients with OM.


METHODS
First, a qualitative phase was conducted to generate items (n = 23). Face validity was assessed by focus group interviews (n = 13). Expert content review (n = 7) was used to ensure content validity. The second step was a quantitative validation phase comprised a multicenter study (n = 210) to help identify subscales of the instrument addressing different dimensions of OM and to measure reliability.


RESULTS
The qualitative interview generated 171 items. Using focus group discussion and expert content review, items were reduced to 41 items. Factor and scaling analyses of these 41 items resulted in 4 subscales, contributed by 31 items, depicting problems with symptoms, diet, social function, and swallowing. The floor effect was modest. The factorial structure was satisfactory with loading >0.40 on each subscale for all items. All corrected item-total corrections were higher than 0.40 (r = 0.457-0.874). The internal consistency reliability of each subscale was high, with Cronbach alpha coefficients ranging from 0.906 to 0.934. The test-retest reliability of the individual items using weighted kappa was good (kappa values 0.610-0.895). The intraclass correlation results for the subscale totals were all in excess of 0.70 (0.864-0.934).


CONCLUSIONS
An initial psychometric analysis of the OMQoL was encouraging. The OMQoL could provide a valuable tool for the assessment of HQoL of patients with OM.