Development of a psychometric scale to assess satisfaction with dental care among Sri Lankans.

OBJECTIVE

To develop and validate a psychometric scale to assess dental satisfaction among Sri Lankans.

DESIGN

A population based cross sectional study, where the data were collected by a postal questionnaire. A 22-item scale was developed to measure dental satisfaction.

PARTICIPANTS

1,000 Sri Lankans aged 18-75 years, selected by cluster sampling with probability proportionate to size technique, using National Voters' register.

OUTCOME MEASURES

Reliability of the scale was assessed by internal consistency using Cronbach's alpha and corrected item-total correlations. Construct validity was determined by factor analysis and acceptability was assessed by percentage of item-specific non-response.

RESULTS

The overall response rate was 30.9%. Among respondents, analysis was limited to dental care users within two years (n=117). Item-specific non-response was low, ranging from 3.4% to 9.4%. Four (negatively worded) items were removed from the scale due to poor internal consistency (corrected item-total correlations <0.2). After removal, corrected item-total correlations of remaining 18 items were improved, ranging from 0.23 to 0.76. Factor analysis revealed a four factor solution, interpreted as: "outcome of care/clinic context" (8-items), 'factors related to treatment process" (7-items), "convenience" (2-items) and "cost of care" (single item). Identified factors explained 64.56% of the variance of the scale. The Cronbach's alpha values for the first three dimensions were 0.90, 0.87 and 0.60 respectively and for the overall construct it was 0.91.

CONCLUSIONS

The present scale appeared to be a valid and reliable instrument for measuring dental satisfaction among Sri Lankans, but merits further refinements to explore detailed aspects of it.