Case study of linking dental and medical healthcare records.
OBJECTIVE
To link the administrative data of a large dental carrier and an integrated health plan in Washington State to conduct an observational study of diabetes and periodontal disease.


METHODS
Evaluation of variable suitability, testing of linkage variables, and performing an n - 1 deterministic linkage strategy.


METHODS
We examined a variety of administrative data variables for their consistency over time and their information richness to use as matching variables. After choosing social security number, date of birth, first name, and last name, we tested their reliability as linking variables among a population with dual dental and medical insurance. Lastly, we performed four n - 1 deterministic linkage steps to obtain our study population.


RESULTS
With a success match rate of more than 96% with the 4 test variables, we extracted the entire population who met the study criteria with the understanding that only a subset would successfully link. We linked 78,230 individuals (55.2% of the Group Health Cooperative population). Of these matches more than 50% occurred within a last name-first name-birth date deterministic match.


CONCLUSIONS
Employer groups who provide dental-medical benefits for their employees send identical administrative data to dental and healthcare plans. The n - 1 deterministic linkage was accomplished by using a relatively straightforward approach because these data were fairly homogeneous and of high quality. Until medical care and dental care are integrated, it is possible to link these data to assess the impact of oral disease on overall health.
Group Health Center for Health Studies, 1730 Minor Ave, Ste 1600, Seattle, WA 98101, USA. reid.rj@ghc.org
Mary Kay
MK
Theis
Robert J
RJ
Reid
Monica
M
Chaudhari
Katherine M
KM
Newton
Leslie
L
Spangler
David C
DC
Grossman
Ronald E
RE
Inge
D000328:Adult; D003729:Dental Care; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008329:Managed Care Programs; D008498:Medical Record Linkage / Q000379:methods*; D008875:Middle Aged; D019982:Organizational Case Studies; D011320:Primary Health Care; D014861:Washington