Background: General practitioners play a central role in taking
deprivation into consideration when caring for patients in primary care.
Validated questions to identify deprivation in primary-care practices are
still lacking. For both clinical and research purposes, this study therefore
aims to develop and validate a standardized instrument measuring both
material and social deprivation at an individual level.
Methods: The Deprivation in Primary Care Questionnaire (DiPCare-Q)
was developed using qualitative and quantitative approaches between
2008 and 2011. A systematic review identified 199 questions related to
deprivation. Using judgmental item quality, these were reduced to 38
questions. Two focus groups (primary-care physicians, and primary-care
researchers), structured interviews (10 laymen), and think aloud
interviews (eight cleaning staff) assured face validity. Item response
theory analysis was then used to derive the DiPCare-Q index using
data obtained from a random sample of 200 patients who were to
complete the questionnaire a second time over the phone. For construct
and criterion validity, the final 16 questions were administered to a
random sample of 1,898 patients attending one of 47 different private
primary-care practices in western Switzerland (validation set) along with
questions on subjective social status (subjective SES ladder),
education, source of income, welfare status, and subjective poverty.
Results: Deprivation was defined in three distinct dimensions (table);
material deprivation (eight items), social deprivation (five items) and
health deprivation (three items). Item consistency was high in both the
derivation (KR20 = 0.827) and the validation set (KR20 = 0.778). The
DiPCare-Q index was reliable (ICC = 0.847). For construct validity, we
showed the DiPCare-Q index to be correlated to patients' estimation of
their position on the subjective SES ladder (rs = 0.539). This position
was correlated to both material and social deprivation independently
suggesting two separate mechanisms enhancing the feeling of
deprivation.
Conclusion: The DiPCare-Q is a rapid, reliable and validated
instrument useful for measuring both material and social deprivation in
primary care. Questions from the DiPCare-Q are easy to use when
investigating patients' social history and could improve clinicians' ability
to detect underlying social distress related to deprivation.