42 research outputs found
An Analysis of Electronically Monitored Adherence to Antiretroviral Medications
Medication adherence studies increasingly collect data electronically, often using Medication Event Monitoring System (MEMS) caps. Analyses typically focus on summary adherence measures, although more complete analyses are possible using adaptive statistical methods. These methods were used to describe individual-subject adherence patterns for MEMS data from a clinical trial. Subjects were adaptively clustered into groups with similar adherence patterns and clusters were compared on a variety of subject characteristics. There were seven different adherence clusters: consistently high, consistently moderately high, consistently moderate, consistently moderately low, consistently low, deteriorating starting early, and deteriorating late. Compared to other subjects, subjects with consistently high and consistently moderately high adherence were more likely to be male, White, and older and to maintain during study participation a CD4 cell count over 500 and an HIV viral load of at most 400 copies/ml. These results demonstrate the effectiveness of adaptive methods for comprehensive analysis of MEMS data
Development and validation of vulnerable and enabling indices for hiv viral suppression among people with hiv enrolled in the ryan white program
Background: Numerous factors impact HIV care, often requiring consideration of indices to prevent collinearity when using statistical modeling. Using the Behavioral Model for Vulnerable Populations, we developed vulnerable and enabling indices for people living with HIV (PLWH). Methods: We used Ryan White Program (RWP) data and principal component analysis to develop general and gender-and racial/ethnic-specific indices. We assessed internal reliability (Cronbach’s alpha), convergent validity (correlation coefficient), and predictive utility (logistic regression) with non-viral suppression. Results: Three general factors accounting for 79.2% of indicators’ variability surfaced: mental health, drug use, and socioeconomic status (Cronbach’s alpha 0.68). Among the overall RWP population, indices showed convergent validity and predictive utility. Using gender-or racial/ethnic-specific indices did not improve psychometric performance. Discussion: General mental health, drug use, and socioeconomic indices using administrative data showed acceptable reliability, validity, and utility for non-viral suppression in an overall PLWH population and in gender-and racial/ethnic-stratified populations. These general indices may be used with similar validity and utility across gender and racial/ethnic diverse populations
Streptococcus pneumoniae Clonal Complex 199: Genetic Diversity and Tissue-Specific Virulence
Streptococcus pneumoniae is an important cause of otitis media and invasive disease. Since introduction of the heptavalent pneumococcal conjugate vaccine, there has been an increase in replacement disease due to serotype 19A clonal complex (CC)199 isolates. The goals of this study were to 1) describe genetic diversity among nineteen CC199 isolates from carriage, middle ear, blood, and cerebrospinal fluid, 2) compare CC199 19A (n = 3) and 15B/C (n = 2) isolates in the chinchilla model for pneumococcal disease, and 3) identify accessory genes associated with tissue-specific disease among a larger collection of S. pneumoniae isolates. CC199 isolates were analyzed by comparative genome hybridization. One hundred and twenty-seven genes were variably present. The CC199 phylogeny split into two main clades, one comprised predominantly of carriage isolates and another of disease isolates. Ability to colonize and cause disease did not differ by serotype in the chinchilla model. However, isolates from the disease clade were associated with faster time to bacteremia compared to carriage clade isolates. One 19A isolate exhibited hypervirulence. Twelve tissue-specific genes/regions were identified by correspondence analysis. After screening a diverse collection of 326 isolates, spr0282 was associated with carriage. Four genes/regions, SP0163, SP0463, SPN05002 and RD8a were associated with middle ear isolates. SPN05002 also associated with blood and CSF, while RD8a associated with blood isolates. The hypervirulent isolate's genome was sequenced using the Solexa paired-end sequencing platform and compared to that of a reference serotype 19A isolate, revealing the presence of a novel 20 kb region with sequence similarity to bacteriophage genes. Genetic factors other than serotype may modulate virulence potential in CC199. These studies have implications for the long-term effectiveness of conjugate vaccines. Ideally, future vaccines would target common proteins to effectively reduce carriage and disease in the vaccinated population
Genomic Subtraction Followed by Dot Blot Screening of Streptococcus pneumoniae Clinical and Carriage Isolates Identifies Genetic Differences Associated with Strains That Cause Otitis Media
Streptococcus pneumoniae strains are the leading cause of bacterial otitis media, yet little is known about specific bacterial factors important for this disease. We utilized a molecular epidemiological approach involving genomic subtraction of the S. pneumoniae serogroup 19 middle ear strain 5093 against the laboratory strain R6. Resulting subtraction PCR (sPCR) products were used to screen a panel of 93 middle ear, 90 blood, 35 carriage, and 58 cerebrospinal fluid isolates from young children to identify genes found more frequently among middle ear isolates. Probe P41, similar to a hypothetical protein of Brucella melitensis, occurred among 41% of middle ear isolates and was found 2.8 (95% confidence interval [CI], 1.32 to 6.5), 3.3 (95% CI, 1.9 to 5.7), and 1.8 (95% CI, 1.1 to 3.0) times more frequently among middle ear strains than carriage, blood, or meningitis strains, respectively. sPCR fragment H10, similar to an unknown Streptococcus agalactiae protein, was present in 31% of middle ear isolates and occurred 3.6 (95% CI, 1.2 to 11.2), 2.8 (95% CI, 1.5 to 5.4), and 2.6 (95% CI, 1.2 to 5.5) times more often among middle ear isolates than carriage, blood, or meningitis strains, respectively. These studies have identified two genes of potential importance in otitis media virulence. Further studies are warranted to outline the precise role of these genes in otitis media pathogenesis
Adjusting and censoring electronic monitoring device data. Implications for study outcomes
Electronic monitoring device (EMD) data are widely used to measure adherence in HIV medication adherence research. EMD data represent an objective measure of adherence and arguably provide more valid data than other methods such as self-reported measures, pill counts, and drug level concentration. Moreover, EMD data are longitudinal, include many measurements, and yield a rich data set. This article illustrates potential pitfalls associated with this measurement technique, including lack of clarity associated with EMD data, and the extent to which adherence outcomes are affected by data management decisions. Recommendations are given regarding what information should be included in publications that report results based on EMD data so as to facilitate comparisons between studies
Knowledge, attitudes, behaviors, and perceptions of risk related to HIV/AIDS among Chinese university students in Hunan, China
The purpose of this paper is to describe HIV/AIDS knowledge, attitudes, and perceptions and identify personal risk behaviors among undergraduate students in China. A descriptive, cross-sectional survey of 1326 students between ages 17 through 28 was conducted in 2002. Results indicated that students held considerable misconceptions about HIV transmission by casual contact and needle sharing as well as stigmatizing attitudes about injection drug use, homosexuality and HIV-positive women who bear children. Results indicated that 14% of Chinese university students are sexually active and risk behaviors tended to increase with age. Additionally, 24% of the students considered themselves to be at moderate to very high risk of contracting HIV and 40% of sexually active students never used condoms. Therefore, it is important to design HIV prevention strategies that target university students in China
The health care relationship (HCR) trust scale: development and psychometric evaluation
A sequential multi-method approach using focus groups, individual interviews, and quantitative instrument development procedures was used to develop and evaluate a scale to measure patient trust in health care providers (HCPs). The resulting 15-item Health Care Relationship (HCR) Trust Scale was tested for internal consistency, test-retest reliability, and construct validity. The Cronbach alphas were .92 (time 1) and .95 (time 2), respectively. Test-retest reliability was .59 (p \u3c .01). The HCR Trust Scale did not correlate with the Marlowe-Crowne Social Desirability Scale (r = .20, p = .07) or the Rapid Estimate of Adult Literacy in Medicine scale (r = -.21, p = .13). Principal component factor analysis with varimax rotation revealed a three-factor solution that explained 69% of the estimated common variance in the HCR trust scale. Cronbach alphas for the 3 factors ranged from .81 to .89. Findings of this study support the use of the HCR Trust Scale for measuring trust in various HCPs by diverse patient populations. More work is needed to test the usefulness of the scale with a greater number of patients and in other chronic illness populations
Electronic monitoring device event modelling on an individual-subject basis using adaptive Poisson regression
An adaptive approach to Poisson regression modelling is presented for analysing event data from electronic devices monitoring medication-taking. The emphasis is on applying this approach to data for individual subjects although it also applies to data for multiple subjects. This approach provides for visualization of adherence patterns as well as for objective comparison of actual device use with prescribed medication-taking. Example analyses are presented using data on openings of electronic pill bottle caps monitoring adherence of subjects with HIV undergoing highly active antiretroviral therapies. The modelling approach consists of partitioning the observation period, computing grouped event counts/rates for intervals in this partition, and modelling these event counts/rates in terms of elapsed time after entry into the study using Poisson regression. These models are based on adaptively selected sets of power transforms of elapsed time determined by rule-based heuristic search through arbitrary sets of parametric models, thereby effectively generating a smooth non-parametric regression fit to the data. Models are compared using k-fold likelihood cross-validation
Deaths Due to Screenable Cancers Among People Living With HIV Infection, Florida, 2000-2014
INTRODUCTION: Because of antiretroviral therapy, people living with HIV infection are surviving longer and are at higher risk for chronic diseases. This study's objective was to assess the magnitude of deaths due to cancers for which there are screening recommendations for people living with HIV in Florida. METHODS: Florida Department of Health Enhanced HIV/AIDS Reporting System data were matched with Department of Health Vital Records and the National Death Index to identify deaths and their causes through 2014. The sex-specific and cause-specific mortality rates and indirect standardized mortality ratios (SMRs, using U.S. mortality rates as a standard) were calculated during 2016 for people reported with HIV infection 2000-2014.RESULTS: Despite the competing risk of HIV mortality, among the 25,678 females, there was a higher risk of cervical (SMR=6.32, 95% CI=4.63, 8.44), colorectal (SMR=2.05, 95% CI=1.44, 2.83), liver (SMR=8.96, 95% CI=5.39, 14.03), and lung (SMR=5.82, 95% CI=4.80, 6.96) cancer mortality and lower risk of breast cancer mortality (SMR=0.57, 95% CI=0.42, 0.76). Among 63,493 males, there was a higher risk of liver (SMR=5.50, 95% CI=4.47, 6.70) and lung (4.63, 95% CI=4.11, 5.19) cancer mortality. Among males, the lung cancer SMR significantly declined 2000-2014 (p<0.05), but was still high in 2012-2014 (SMR=3.59, 95% CI=2.87, 4.43). CONCLUSIONS: These results indicate the importance of primary and secondary cancer prevention during primary care for people living with HIV infection.</p