Explained variation in a model of therapeutic decision making is partitioned across patient, physician, and clinic factors.
OBJECTIVE
Data on therapeutic decision making have a multilevel structure that can include patient-, provider-, and facility-level variables. A statistical method is presented for attributing explained variation in patient care to different levels of aggregation in a multilevel model with the aim of prioritizing and targeting quality improvement interventions.


METHODS
The proposed method is used in an analysis of adherence to evidence-based guidelines for the care of patients at risk of osteoporosis. Explained variation from a multilevel model of appropriate care is partitioned across patient-, physician-, and clinic-level factors.


RESULTS
The combination of patient, physician, and clinic factors explained 20.0% of the variation in patient care. Individual physician effects explained 14.0% of the variation in the data; however, more than half of this explained variation could have been attributed to the individual clinic effect. Patient fixed effects alone explained 13.4% of the variation in the observed clinical decisions.


CONCLUSIONS
The proposed approach is an intuitive and statistically valid method for attributing explained variation in a multilevel analysis of therapeutic decision making.
Brookhart
M Alan
MA
Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital-Harvard Medical School, 1620 Tremont Street, Suite 3030, Boston, MA 02120, USA. abrookhart@rics.bwh.harvard.edu
Solomon
Daniel H
DH
Wang
Philip
P
Glynn
Robert J
RJ
Avorn
Jerry
J
Schneeweiss
Sebastian
S
D000284:Administration, Oral; D000368:Aged; D003657:Decision Making; D019317:Evidence-Based Medicine; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology; D005938:Glucocorticoids / Q000008:administration & dosage; D019983:Guideline Adherence; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D010024:Osteoporosis / Q000517:prevention & control*; D010358:Patient Participation; D010819:Physician's Role; D010817:Physician-Patient Relations; D012307:Risk Factors; D012907:Smoking
D005938:Glucocorticoids