Validity and reliability of the Brazilian Primary Care Assessment Tool: Oral Health of Adults.

To test the factorial validity and reliability of the Primary Care Assessment Tool adapted to Oral Health, adult patient version, an instrument used to verify the presence and extent of attributes in Primary Health Care services. Population-based cross-sectional study using conglomerate random sample carried out in Primary Health Care Dental services in Porto Alegre between 2011 and 2013. We interviewed 407 adult patients who used Primary Health Care Dental services. Construct validity was tested through factorial validity and reliability of the Primary Care Assessment Tool, that comprises 81 items distributed throughout Primary Health Care attributes. Equamax orthogonal rotation method was used in the factorial analysis; and, in order to assess reliability of each component, we used the item-total correlation and the ratio of success of the scale. In the factorial analysis, 10 factors were retained, explaining 53.3% of the total variation. This result demonstrates the multidimensional structure of the instrument. The reliability assessment showed Cronbach's alpha values ranging from 0.39 to 0.89. For the success of the scale most of the results (eight of nine attributes) were greater than 85%. The instrument is valid for the assessment of oral health services in Primary Health Care from the perspective of adult patients, as well as for monitoring and evaluation of oral health services in Primary Health Care attributes and comparative studies.