TREATMENT FOR PATIENTS DIAGNOSED WITH PARKINSON'S DISEASE- DIFFERENCES BASED UPON DIAGNOSING PHYSICIAN

OBJECTIVES: To investigate Parkinson’s disease (PD) medication initiation patterns based upon diagnosing physician specialty. METHODS: Data were obtained from the i3 InVisionTM Data Mart database from January 1, 2006 through March 30, 2011.  Patients included in the analyses were diagnosed with PD (initial diagnosis identified as index date) and had continuous insurance coverage from 6 months prior through 12 months post index date, and were at least age 35.  Categorical variables were examined using chi-square statistics while continuous variables were examined using t-tests; all are descriptive. RESULTS: A total of 5967 patients fit the study criteria.  Patients diagnosed by a neurologist (N=3173), compared to those diagnosed by another physician specialty, were more likely to be male (58.86% vs. 53.72%; P=0.0002), younger (66.53 years vs. 70.81 years; P<0.0001), and in better health, as proxied by the Charlson Comorbidity Index (1.14 vs. 1.28; P=0.0034).  Patients diagnosed by a neurologist were significantly more likely to be treated with a PD medication during the study period (48.91% vs. 30.06%; P<0.0001).  A neurologist was significantly more likely to initially prescribe a monoamine oxidase B inhibitor (MAO-B) (21.07% vs. 12.86%; P<0.0001) or carbidopa/levodopa/entacapone (9.86% vs. 6.43%; P=0.0004), than a physician of another specialty, but significantly less likely to initially prescribe carbidopa/levodopa (27.90% vs. 42.38%; P<0.0001).  There was no difference in the rates of switching from initial class of PD medication or adjunctive use of an additional class of PD medication, although among patients prescribed multiple classes of PD medications, patients diagnosed by a neurologist were more likely to be prescribed a dopamine agonist in combination with a MAO-B (40.08% vs. 27.34%; P=0.0147).  CONCLUSIONS: These analyses found differences in treatment patterns based upon the specialty of the diagnosing physician.  Additional studies are warranted to raise awareness of differences in PD treatment by diagnosing physician and to address potential health care disparities.