Reported mortality rates from Clostridium difficile disease in the United States increased from 5.7 per million population in 1999 to 23.7 per million in 2004. Increased rates may be due to emergence of a highly virulent strain of C. difficile. Rates were higher for whites than for other racial/ethnic groups.

There is considerable variation in the phenotypic appearance of individuals with idiopathic Parkinson's disease (PD), which may translate into differences in disease progression in addition to underlying disease etiology. In this publication, we report on the demographic and clinical characteristics of 162 individuals diagnosed with clinically probable PD from January 1998 to June 2003 who resided in predominantly rural communities in central California. The majority of the subjects were Caucasian, male, and between 60 and 79 years of age. The akinetic-rigid and tremor-dominant subtypes were more common than the mixed subtype. The majority of subjects displayed motor signs of rigidity (92.0%), bradykinesia (95.7%), and gait problems (87.0%), whereas less than half (43.3%) of the subjects displayed a tremor. Three fourths of patients received a Hoehn and Yahr Scale score of Stage 2 or higher. One third of the patients were treated with levodopa, and patients under 60 years of age were more likely to be treated with dopamine agonists. Within 3 years after first diagnosis, 13% of subjects showed some signs of depression and 17% of subjects met criteria for mild dementia. Among our subjects, 17.3% reported a family history of PD in first-or second-degree relatives,15.4% a family history of essential tremor, and 14.2% of Alzheimer's disease. This study represents the most extensive phenotypic description of rural U.S. residents in the initial stages of PD who were recruited in a population-based manner; future follow-up may provide valuable information regarding the prognostic indication of these symptoms/signs and improve our understanding of the underlying etiology of PD.Keywords idiopathic Parkinson's disease (PD); phenotypic description; disease progression; etiology; population-based studyThe neurologic community agrees that the core features for diagnosing idiopathic Parkinson's disease (PD) clinically are resting tremor, bradykinesia, rigidity, and postural instability. However, in individual patients there is considerable variation in the expression and predominance of each classic clinical sign and also in accompanying symptoms and disease course. Furthermore, there are many aspects of motor and nonmotor function in PD NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript that contribute to quite heterogeneous disease phenotypes. Some variations in presentation and course of disease may not only help to distinguish phenotypical subtypes that require treatment modifications and have different prognoses but, in addition, may reflect differences in underlying disease etiology, including varying responses to environmental and genetic susceptibility factors. Geneticists recently pointed out the importance of thoroughly documenting phenotype for the study of genetic contributions to many complex diseases such as asthma and adult-onset diabetes when studying gene to environment and gene to gene interactions. 1 Thus, with genetic studies of PD accumulating over the past 5 years, it may b...

Death rarely results from only one cause, and it can be caused by a variety of factors. Multiple cause-of-death data files can list as many as 20 contributing causes of death in addition to the reported underlying cause of death. Analysis of multiple cause-of-death data can provide information on associations between causes of death, revealing common combinations of events or conditions which lead to death. Additionally, physicians report the causal train of events through which they believe that different conditions or events may have led to each other and ultimately caused death. In this paper, the authors discuss methods used in studying associations between reported causes of death and in investigating commonly reported causal pathways between events or conditions listed on the death certificate.

Whenever possible, underlying and multiple cause-of-death statistics should both be presented. Analyses that use only the underlying cause of death ignore additional information that is readily available from multiple-cause data, and the more limited data may underestimate the importance of several leading causes of death.

Multiple sclerosis (MS) is a neurodegenerative condition that can result in cognitive and physical disability and shortened life expectancy. However, population-based information is lacking regarding the mortality burden from MS in the United States. We investigated trends in MS mortality rates and examined important comorbidities in the United States from 1990 to 2001. MS deaths were matched by age, sex, and race/ethnicity with randomly selected deaths from other conditions for matched odds ratio comparisons. The overall age-adjusted mortality rate from MS was 1.44/100,000 population. MS mortality rates increased throughout the study period. MS mortality rates were higher in whites than in any other racial/ethnic group, followed by Blacks, Hispanics, American Indians/Alaska Natives, and Asians and Pacific Islanders. Observed mortality rates were more than 10 times lower in Asians and Pacific Islanders than in whites. The odds of pressure ulcers, urinary tract infections, and pneumonia/influenza being reported on the death certificate were higher in MS deaths than in matched controls.