Allison W. Willis

Geographic and ethnic variation in Parkinson disease: a population-based study of US Medicare beneficiaries.

Background: Parkinson disease is a common neurodegenerative disease. The racial, sex, age, and geographic distributions of Parkinson disease in the US are unknown. Methods: We performed a serial cross-sectional study of US Medicare beneficiaries aged 65 and older from the years 1995, and 2000–2005. Using over 450,000 Parkinson disease cases per year, we calculated Parkinson disease prevalence and annual incidence by race, age, sex, and county. Spatial analysis investigated the geographic distribution of Parkinson disease. Results: Age-standardized Parkinson disease prevalence (per 100,000) was 2,168.18 (±95.64) in White men, but 1,036.41 (±86.01) in Blacks, and 1,138.56 (±46.47) in Asians. The incidence ratio in Blacks as compared to Whites (0.74; 95% CI = 0.732–0.748) was higher than the prevalence ratio (0.58; 95% CI = 0.575–0.581), whereas the incidence ratio for Asians (0.69; 95% CI = 0.657–0.723) was similar to the prevalence ratio (0.62; 95% CI = 0.617–0.631). Bayesian mapping of Parkinson disease revealed a concentration in the Midwest and Northeast regions. Mean county incidence by quartile ranged from 279 to 3,111, and prevalence from 1,175 to 13,800 (per 100,000). Prevalence and incidence in urban counties were greater than in rural ones (p < 0.01). Cluster analysis supported a nonrandom distribution of both incident and prevalent Parkinson disease cases (p < 0.001). Conclusions: Parkinson disease is substantially more common in Whites, and is nonrandomly distributed in the Midwest and Northeastern US.

Metal Emissions and Urban Incident Parkinson Disease: A Community Health Study of Medicare Beneficiaries by Using Geographic Information Systems

Parkinson disease associated with farming and exposure to agricultural chemicals has been reported in numerous studies; little is known about Parkinson disease risk factors for those living in urban areas. The authors investigated the relation between copper, lead, or manganese emissions and Parkinson disease incidence in the urban United States, studying 29 million Medicare beneficiaries in the year 2003. Parkinson disease incidence was determined by using beneficiaries who had not changed residence since 1995. Over 35,000 nonmobile incident Parkinson disease cases, diagnosed by a neurologist, were identified for analysis. Age-, race-, and sex-standardized Parkinson disease incidence was compared between counties with high cumulative industrial release of copper, manganese, or lead (as reported to the Environmental Protection Agency) and counties with no/low reported release of all 3 metals. Parkinson disease incidence (per 100,000) in counties with no/low copper/lead/manganese release was 274.0 (95% confidence interval (CI): 226.8, 353.5). Incidence was greater in counties with high manganese release: 489.4 (95% CI: 368.3, 689.5) (relative risk = 1.78, 95% CI: 1.54, 2.07) and counties with high copper release: 304.2 (95% CI: 276.0, 336.8) (relative risk = 1.1, 95% CI: 0.94, 1.31). Urban Parkinson disease incidence is greater in counties with high reported industrial release of copper or manganese. Environmental exposure to metals may be a risk factor for Parkinson disease in urban areas.

Neurologist-associated reduction in PD-related hospitalizations and health care expenditures

Objective: To investigate the impact of neurologist care on Parkinson disease (PD)–related hospitalizations. Recent data indicate that neurologist treatment in PD may be associated with improved survival, yet is underutilized. Factors contributing to this improved survival remain unknown, but may be due in part to optimal disease treatment or avoidance of disease-related complications. Methods: This was a retrospective cohort study of Medicare beneficiaries diagnosed with PD in 2002 and still living in 2006. Hospitalization for PD-related (neurodegenerative disease, psychosis, depression, urinary tract infection, and traumatic injury) and general medical (hypertension, diabetes, congestive heart failure, angina, and gastrointestinal obstruction) illnesses was compared by PD treating physician specialty using Cox proportional hazard models, adjusting for confounders. Secondary analyses included PD-related rehospitalization and cost stratified by frequency of neurologist care. Results: We identified 24,929 eligible incident PD cases; 13,489 had neurologist care. There were 9,112 PD-related hospitalizations, and these occurred and recurred less often among neurologist-treated patients. Neurologist PD care was associated with lower adjusted odds of both initial and repeat hospitalization for psychosis (hazard ratio [HR] 0.71, 95% confidence interval [CI] 0.59–0.86), urinary tract infection (HR 0.74, 0.63–0.87), and traumatic injury (HR 0.56, 0.40–0.78). PD-related outcomes improved with frequency of neurologist care in a stepwise manner. Odds of general illness hospitalization or hospitalization did not differ by neurologist involvement. Conclusions: Regular neurologist care in PD is specifically associated with lower risk of hospitalization and rehospitalization for several PD-related illnesses. This may reflect an improved ability of neurologists to prevent, recognize, or treat PD complications.

Disparities in deep brain stimulation surgery among insured elders with Parkinson disease

Objective: To identify sociodemographic, clinical, and physician/practice factors associated with deep brain stimulation (DBS). DBS is a proven surgical therapy for Parkinson disease (PD), but is recommended only for patients with excellent health, results in significant out-of-pocket costs, and requires substantial physician involvement. Methods: Retrospective cohort study of more than 657,000 Medicare beneficiaries with PD. Multivariable logistic regression models examined the association between demographic, clinical, socioeconomic status (SES), and physician/practice factors, and DBS therapy. Results: There were significant disparities in the use of DBS therapy among Medicare beneficiaries with PD. The greatest disparities were associated with race: black (adjusted odds ratio [AOR] 0.20, 95% confidence interval [CI] 0.16–0.25) and Asian (AOR 0.55, 95% CI 0.44–0.70) beneficiaries were considerably less likely to receive DBS than white beneficiaries. Women (AOR 0.79, 95% CI 0.75–0.83) also had lower odds of receiving DBS compared with men. Eighteen percent of procedures were performed on patients with PD who had cognitive impairment/dementia, a reported contraindication to DBS. Beneficiaries treated in minority-serving PD practices were less likely to receive DBS, regardless of individual race (AOR 0.76, 95% CI 0.66–0.87). Even after adjustment for demographic and clinical covariates, high neighborhood SES was associated with 1.4-fold higher odds of receiving DBS (AOR 1.42, 95% CI 1.33–1.53). Conclusions: Among elderly Medicare beneficiaries with PD, race, sex, and neighborhood SES are strong independent predictors of DBS receipt. Racial disparities are amplified when adjusting for physician/clinic characteristics. Future investigations of the demographic differences in clinical need/usefulness of DBS, ease of DBS attainment, and actual/opportunity DBS costs are needed to inform policies to reduce DBS disparities and improve PD quality of care.

Nursing home and end-of-life care in Parkinson disease

Objective: To examine long-term care facility (LTCF or nursing home) use and end-of-life care for individuals with Parkinson disease (PD). Methods: In this nationwide retrospective cohort study, we compared LTCF and hospice utilization among Medicare beneficiaries diagnosed with PD by demographic, clinical, and physician characteristics. We also examined the impact of outpatient neurologist care for institutionalized patients with PD on end-of-life care. Results: We identified 469,055 individuals with PD who received Medicare benefits in 2002. Nearly 25% (more than 100,000 in total) resided in an LTCF. Women with PD had greater odds of nursing facility residence (adjusted odds ratio [AOR] 1.34, 95% confidence interval [CI] 1.30–1.38) compared with men. Black individuals with PD were 34% more likely than white individuals to reside in an LTCF (AOR 1.34, 95% CI 1.30–1.38), contrary to the race patterns typically observed for LTCF use. Hip fracture (AOR 2.10, 95% CI 2.04–2.15) and dementia (AOR 4.06, 95% CI 4.00–4.12) were the strongest clinical predictors of LTCF placement. Only 33% (n = 38,334) of nursing home residents with PD had outpatient neurologist care. Eighty-four percent (n = 80,877) of LTCF residents with PD died by December 31, 2005. Hospice utilization varied little by race and sex. LTCF residents who had outpatient neurologist care were twice as likely to utilize hospice services before death (AOR 2.35, 95% CI 2.24–2.47). Conclusions and relevance: A large proportion of the Medicare PD population resides in an LTCF. There is substantial unmet need for palliative care in the PD population. Increased efforts to provide specialist care to dependent individuals with PD may improve end-of-life care.

Bright light exposure reduces TH-positive dopamine neurons: implications of light pollution in Parkinson's disease epidemiology.

This study explores the effect of continuous exposure to bright light on neuromelanin formation and dopamine neuron survival in the substantia nigra. Twenty-one days after birth, Sprague–Dawley albino rats were divided into groups and raised under different conditions of light exposure. At the end of the irradiation period, rats were sacrificed and assayed for neuromelanin formation and number of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra. The rats exposed to bright light for 20 days or 90 days showed a relatively greater number of neuromelanin-positive neurons. Surprisingly, TH-positive neurons decreased progressively in the substantia nigra reaching a significant 29% reduction after 90 days of continuous bright light exposure. This decrease was paralleled by a diminution of dopamine and its metabolite in the striatum. Remarkably, in preliminary analysis that accounted for population density, the age and race adjusted Parkinsons disease prevalence significantly correlated with average satellite-observed sky light pollution.

Associations between Anticholinergic Burden and Adverse Health Outcomes in Parkinson Disease

Background Elderly adults should avoid medications with anticholinergic effects since they may increase the risk of adverse events, including falls, delirium, and cognitive impairment. However, data on anticholinergic burden are limited in subpopulations, such as individuals with Parkinson disease (PD). The objective of this study was to determine whether anticholinergic burden was associated with adverse outcomes in a PD inpatient population. Methods Using the Cerner Health Facts® database, we retrospectively examined anticholinergic medication use, diagnoses, and hospital revisits within a cohort of 16,302 PD inpatients admitted to a Cerner hospital between 2000 and 2011. Anticholinergic burden was computed using the Anticholinergic Risk Scale (ARS). Primary outcomes were associations between ARS score and diagnosis of fracture and delirium. Secondary outcomes included associations between ARS score and 30-day hospital revisits. Results Many individuals (57.8%) were prescribed non-PD medications with moderate to very strong anticholinergic potential. Individuals with the greatest ARS score (≥4) were more likely to be diagnosed with fractures (adjusted odds ratio (AOR): 1.56, 95% CI: 1.29–1.88) and delirium (AOR: 1.61, 95% CI: 1.08–2.40) relative to those with no anticholinergic burden. Similarly, inpatients with the greatest ARS score were more likely to visit the emergency department (adjusted hazard ratio (AHR): 1.32, 95% CI: 1.10–1.58) and be readmitted (AHR: 1.16, 95% CI: 1.01–1.33) within 30-days of discharge. Conclusions We found a positive association between increased anticholinergic burden and adverse outcomes among individuals with PD. Additional pharmacovigilance studies are needed to better understand risks associated with anticholinergic medication use in PD.

Time to change the blind men and the elephant approach to Parkinson disease

Parkinson disease (PD) is a progressive neurodegenerative disease that is associated with substantial morbidity and early mortality. Disease-related costs exceed

National Randomized Controlled Trial of Virtual House Calls for People with Parkinson's Disease: Interest and Barriers

10 billion, not including medications, out-of-pocket expenses, or societal costs. Symptomatic treatment with levodopa, which has been available for over 30 years, and advanced therapies such as deep brain stimulation improve outcomes. Yet most new medications for PD provide a therapeutic benefit that is relatively modest compared to the benefits from levodopa. Despite dozens of neuroprotective clinical trials, there are no medications proven to slow the progression of the disease. Given these limitations, we provide evidence of the potential public health impact of a research agenda that emphasizes identification of risk factors to reduce disease burden through exposure mitigation. In addition, we emphasize health care policy that focuses on increasing health care expenditures for neurologic evaluation and management services to increase access to specialists to improve disease outcomes and reduce costs through better disease management.

A predictive model to identify Parkinson disease from administrative claims data

BACKGROUND Delivering specialty care remotely directly into peoples homes can enhance access for and improve the healthcare of individuals with chronic conditions. However, evidence supporting this approach is limited. MATERIALS AND METHODS Connect.Parkinson is a randomized comparative effectiveness study that compares usual care of individuals with Parkinsons disease in the community with usual care augmented by virtual house calls with a Parkinsons disease specialist from 1 of 18 centers nationally. Individuals in the intervention arm receive four virtual visits from a Parkinsons disease specialist over 1 year via secure, Web-based videoconferencing directly into their homes. All study activities, including recruitment, enrollment, and assessments, are conducted remotely. Here we report on interest, feasibility, and barriers to enrollment in this ongoing study. RESULTS During recruitment, 11,734 individuals visited the studys Web site, and 927 unique individuals submitted electronic interest forms. Two hundred ten individuals from 18 states enrolled in the study from March 2014 to June 2015, and 195 were randomized. Most participants were white (96%) and college educated (73%). Of the randomized participants, 73% had seen a Parkinsons disease specialist within the previous year. CONCLUSIONS Among individuals with Parkinsons disease, national interest in receiving remote specialty care directly into the home is high. Remote enrollment in this care model is feasible but is likely affected by differential access to the Internet.