Validation of the questionnaire for impulsive‐compulsive disorders in Parkinson's disease

As no comprehensive assessment instrument for impulse control disorders (ICDs) in Parkinson's disease (PD) exists, the aim of this study was to design and assess the psychometric properties of a self‐administered screening questionnaire for ICDs and other compulsive behaviors in PD. The Questionnaire for Impulsive‐Compulsive Disorders in Parkinson's Disease (QUIP) has 3 sections: Section 1 assesses four ICDs (involving gambling, sexual, buying, and eating behaviors), Section 2 other compulsive behaviors (punding, hobbyism, and walkabout), and Section 3 compulsive medication use. For validation, a convenience sample of 157 PD patients at 4 movement disorders centers first completed the QUIP, and then was administered a diagnostic interview by a trained rater blinded to the QUIP results. A shortened instrument (QUIP‐S) was then explored. The discriminant validity of the QUIP was high for each disorder or behavior (receiver operating characteristic area under the curve [ROC AUC]: gambling = 0.95, sexual behavior = 0.97, buying = 0.87, eating = 0.88, punding = 0.78, hobbyism = 0.93, walkabout = 0.79). On post hoc analysis, the QUIP‐S ICD section had similar properties (ROC AUC: gambling = 0.95, sexual behavior = 0.96, buying = 0.87, eating = 0.88). When disorders/behaviors were combined, the sensitivity of the QUIP and QUIP‐S to detect an individual with any disorder was 96 and 94%, respectively. Scores on the QUIP appear to be valid as a self‐assessment screening instrument for a range of ICDs and other compulsive behaviors that occur in PD, and a shortened version may perform as well as the full version. A positive screen should be followed by a comprehensive, clinical interview to determine the range and severity of symptoms, as well as need for clinical management. © 2009 Movement Disorder Society     

Treatment disparities in Parkinson's disease

We sought to identify racial disparities in the treatment of Parkinson's disease (PD). We identified 307 incident PD cases using Pennsylvania State Medicaid claims, and extracted claims for medications, physical therapy, and healthcare visits for the 6 months after diagnosis. After controlling for age, sex, and geography, African‐Americans were four times less likely than whites to receive any PD treatment (odds ratio, 0.24; 95% confidence interval, 0.09–0.64), especially indicated medications. In a group with the same healthcare insurance, disparities in PD treatment exist. Physician and community awareness of these racial differences in PD treatment is the first step in addressing healthcare disparities. Ann Neurol 2009;66:142–145     

Cost implications of new treatments for advanced colorectal cancer

BACKGROUND:

Since 1996, 6 new drugs have been introduced for the treatment of metastatic colorectal cancer. Although they are promising, these drugs frequently are given in the palliative and are much more expensive than older treatments. The objective of the current study was to measure the cost implications of treatment with sequential regimens that include chemotherapy and/or monoclonal antibodies.

METHODS:

A Markov model was used to evaluate a hypothetical cohort of 1000 patients with newly diagnosed, metastatic colorectal cancer. Patients supposedly received up to 3 lines of treatment before supportive care and subsequent death. Data were obtained from published, multicenter phase 2 and randomized phase 3 clinical trials. Sensitivity analyses were conducted on the efficacy, toxicity, and cost.

RESULTS:

Using drug costs alone, treatment that included new chemotherapeutic agents increased survival at an incremental cost‐effectiveness ratio (ICER) of $100,000 per discounted life‐year (DLY). The addition of monoclonal antibodies improved survival at an ICER of >$170,000 per DLY. The results were most sensitive to changes in the initial regimen. Even with significant improvements in clinical characteristics (efficacy and toxicity), treatment with the most effective regimens still had very high ICERs.

CONCLUSIONS:

Treatment of metastatic colorectal cancer with the most effective regimens came at very high incremental costs. The authors concluded that cost‐effectiveness analyses should be a routine component of the drug‐development process, so that physicians and patients are informed appropriately regarding the value of new innovations. Cancer 2009. © 2009 American Cancer Society.     

Racial differences in the diagnosis of Parkinson's disease

The objective of this cohort study was to determine the incidence of Parkinson's disease (PD) and the effects of race/ethnicity, other demographic characteristics, geography, and healthcare utilization on probability of diagnosis. The authors used the Pennsylvania state Medicaid claims dataset from 1999 to 2003 to identify newly diagnosed cases of PD among the 182,271 Medicaid enrolled adults age 40–65; 319 incident cases of PD were identified. The 4‐year cumulative incidence of PD was 45 per 100,000; 54 per 100,000 among whites, 23 per 100,000 among African‐Americans and 40 per 100,000 among Latinos (P < 0.0001), corresponding to a relative risk (RR) of PD of 0.43 for African‐Americans (P < 0.0001) compared with whites. After adjusting for age, sex, geography, reason for Medicaid eligibility, and average number of visits, African‐Americans were still half as likely to be diagnosed with PD as whites (RR 0.45, P < 0.0001). Older age, more healthcare visits and Medicaid eligibility because of income alone also were significantly associated with PD diagnosis, while male sex was not. Observed racial differences in incidence of PD are not explained by differences in age, sex, income, insurance or healthcare utilization but still may be explained by biological differences or other factors such as education or aging beliefs. Better understanding of the complex biological and social determinants of these disparities is critical to improve PD care. © 2009 Movement Disorder Society