Biomedical subjects

Scarlett L Bellamy

Publications and source records attributed to Scarlett L Bellamy.

6 recordsLinked to original sources

PubMed2006

Consequences of comorbid insomnia symptoms and sleep-related breathing disorder in elderly subjects.

BACKGROUND: The prevalence of sleep-related breathing disorder (SRBD) and insomnia symptoms increases considerably with advancing age, but little is known about their cooccurrence and their effects on daytime functioning when present together. METHODS: Older adults with (cases, n = 99) and without (controls, n = 100) symptoms of insomnia underwent 2 nights of in-laboratory polysomnography, daytime nap, and neurobehavioral testing and completed study questionnaires. Predictors of SRBD were identified (apnea-hypopnea index [indicating number of events per hour], > or =15). Participants were divided into 4 groups--with and without insomnia and with and without SRBD--and the groups were compared on measures of daytime functioning. RESULTS: Cases had a lower rate of SRBD (29.3%) than controls (38.0%). Body mass index (calculated as weight in kilograms divided by height in meters squared) of 30 or higher, neck circumference greater than 15.5 inches, and a history of "loud snoring" or "stops breathing, chokes, or struggles for breath" were independently predictive of SRBD in participants with insomnia symptoms. Having both insomnia symptoms and SRBD was associated with significantly lower daytime functioning and longer psychomotor reaction times compared with having neither condition. CONCLUSION: Because insomnia comorbid with SRBD is associated with the greatest functional impairment, and SRBD is commonly found in the elderly population, health care providers should also consider SRBD in elderly patients with insomnia symptoms.

Aged↗

PubMed2006

Cancer information seeking preferences and experiences: disparities between Asian Americans and Whites in the Health Information National Trends Survey (HINTS).

Little is known about cancer information needs and seeking patterns in the rapidly growing Asian American population. The purpose of this study is to characterize cancer information seeking behaviors and preferences in Asian Americans and to examine their cancer-related knowledge and risk perceptions. Data from the nationally representative Health Information National Trends Survey (HINTS) database were analyzed to compare non-Hispanic Asians and Whites. Asians had lower awareness of the National Institutes of Health and American Cancer Society, were less likely to think that not smoking or quitting smoking would reduce cancer risk, were less knowledgeable about colon cancer screening, and considered their personal cancer risk to be low. Asians and Whites had similar media usage rates. They also had similar rates of preference for cancer information from various sources, although Asians were significantly more likely to prefer print materials. The level of trust of cancer information from doctors was high overall. This study is limited by under-representation of some demographic subpopulations, future surveys should oversample Asians and strive to include higher-risk Asians (e.g., elderly, poorly educated, immigrants, and those with limited English proficiency).

Adult↗

PubMed2005

A dynamic block-randomization algorithm for group-randomized clinical trials when the composition of blocking factors is not known in advance.

We present an algorithm for randomizing units in blocks for controlled trials when the composition of blocking factors is not known in advance. For example, suppose the desired goal of an intervention study is to randomize units to one of two interventions while blocking on a dichotomous factor (e.g., gender), but the total number of units, and therefore number or composition, of males and females among those units assembled for randomization cannot be determined in advance. This situation arises in randomized trials when subjects are scheduled to be randomized as a group, but not all of the subjects show up for the visit. Since investigators do not know which of the scheduled subjects will or will not show up, a dynamic randomization scheme is required to accommodate the unknown composition of the blocking factor once a group of subjects (units) is assembled for randomization. These settings are further complicated when there is more than one blocking factor. In this paper, we present an algorithm that ensures the integrity of the randomization process in these settings.

Acquired Immunodeficiency Syndrome↗

PubMed2005

Coronary artery calcification in renal transplant recipients.

Cardiovascular disease is the leading cause of mortality in renal transplant recipients. Although renal transplant recipients frequently undergo cardiac functional tests prior to surgery, coronary atherosclerosis can remain undetected. Coronary artery calcification (CAC), an early marker of atherosclerosis can be quantified using EBCT. The purpose of this study was to determine the extent and characteristics of CAC at the time of renal transplantation. We evaluated 79 consecutive incident asymptomatic renal transplant recipients. Patients were mostly White (62%), male (54%) and had a deceased donor renal transplant (61%). The mean age was 47 (12.1) years. Sixty-five percentage of subjects had CAC. The mean CAC score was 331.5 (562.4) with a median of 43.3. Older age, presence of diabetes, not having a preemptive transplant, deceased donor transplantation and hypercholesterolemia were significantly associated with presence of CAC univariately. Median CAC scores were significantly increased in subjects with diabetes (127.8 vs. 28.9, p=0.05), exposed to dialysis (102.9 vs. 3.7, p<0.001) and deceased donor recipients (169.7 vs. 7.5, p=0.02). Using multiple logistic regression, age and time on dialysis were significantly associated with the presence of CAC at the time of transplant. In summary, CAC is prevalent in patients undergoing kidney transplant. CAC may be a method to identify renal transplant recipients at increased risk for future cardiovascular events.

Adult↗

PubMed2004

Analysis of clustered and interval censored data from a community-based study in asthma.

Many authors in recent years have proposed extensions of familiar survival analysis methodologies to apply in dependent data settings, for example, when data are clustered or subject to repeated measures. However, these extensions have been considered largely in the context of right censored data. In this paper, we discuss a parametric frailty model for the analysis of clustered and interval censored failure time data. Details are presented for the specific case where the underlying time to event data follow a Weibull distribution. Maximum likelihood estimates will be obtained using commercially available software and the empirical efficiency of these estimators will be explored via a simulation study. We also discuss a score test to make inferences about the magnitude and significance of over-dispersion in clustered data settings. These methods will be illustrated using data from the East Boston Asthma Study.

Asthma↗

PubMed2004

Influence of alcohol use, race, and viral coinfections on spontaneous HCV clearance in a US veteran population.

Hepatitis C virus (HCV) is spontaneously cleared in 15% to 45% of individuals during primary infection. To define the role of alcohol, race, and HBV or HIV coinfections in natural HCV clearance, we examined these parameters in 203 spontaneously HCV-recovered subjects (HCV Ab(+)/RNA(-) subjects without prior antiviral therapy) and 293 chronically HCV-infected patients (HCV Ab(+)/RNA(+)). Subjects were identified from 1,454 HCV antibody-seropositive US veterans tested for HCV RNA between January 2000 and July 2002 at the Philadelphia Veterans Affairs Medical Center. In univariate analysis, alcohol use disorder (odds ratio [OR] 0.52; 95% CI, 0.31-0.85; P =.006) and black race (OR 0.65; 95% CI, 0.44-0.96; P =.024) were both associated with decreased likelihood of spontaneous HCV clearance. In multivariate analyses adjusting for race, HIV infection, age, and alcohol use disorder, alcohol remained strongly associated with reduced HCV clearance (OR 0.49; 95% CI, 0.30-0.81; P =.005). In contrast, the association between black race and viral clearance was no longer statistically significant (adjusted OR 0.72; 95% CI, 0.48-1.09; P =.125). HIV coinfection was negatively associated with HCV clearance (OR 0.37; 95% CI, 0.16-0.83; P =.016), while HBV coinfection was positively associated with HCV clearance (unadjusted OR 5.0; 95% CI, 1.26-28.6; P =.008). In conclusion, the likelihood of spontaneous clearance of HCV may be influenced by alcohol and viral coinfections.

Alcohol Drinking↗