Modeling Survival After Diagnosis of a Specific Disease Based on Case Surveillance Data

Motivated by a study assessing the impact of treatments on survival of AIDS (Acquired Immune Deficiency Syndrome) patients, we developed a semi-parametric method to estimate the life expectancy after diagnosis using data from case surveillance. With the proposed method, the life expectancy is estimated based on the traditional non-parametric life table method, but the age-specific death rates are estimated using a parametric model to derive more robust estimates from limited numbers of deaths by single year of age. The uncertainties associated with the semi-parametric estimates are provided. In addition, the life expectancy among people with the disease is compared with the life expectancy among those with similar demographic characteristics in the general population. The average years of life lost is used to measure the impact of the disease or the treatment on the survival after diagnosis. The trend of impact over time can be evaluated by the annual estimates of life expectancy and average years of life lost in the past

Estimated HIV Incidence in the United States, 2006–2009

Background The estimated number of new HIV infections in the United States reflects the leading edge of the epidemic. Previously, CDC estimated HIV incidence in the United States in 2006 as 56,300 (95% CI: 48,200–64,500). We updated the 2006 estimate and calculated incidence for 2007–2009 using improved methodology. Methodology We estimated incidence using incidence surveillance data from 16 states and 2 cities and a modification of our previously described stratified extrapolation method based on a sample survey approach with multiple imputation, stratification, and extrapolation to account for missing data and heterogeneity of HIV testing behavior among population groups. Principal Findings Estimated HIV incidence among persons aged 13 years and older was 48,600 (95% CI: 42,400–54,700) in 2006, 56,000 (95% CI: 49,100–62,900) in 2007, 47,800 (95% CI: 41,800–53,800) in 2008 and 48,100 (95% CI: 42,200–54,000) in 2009. From 2006 to 2009 incidence did not change significantly overall or among specific race/ethnicity or risk groups. However, there was a 21% (95% CI:1.9%–39.8%; p = 0.017) increase in incidence for people aged 13–29 years, driven by a 34% (95% CI: 8.4%–60.4%) increase in young men who have sex with men (MSM). There was a 48% increase among young black/African American MSM (12.3%–83.0%; p<0.001). Among people aged 13–29, only MSM experienced significant increases in incidence, and among 13–29 year-old MSM, incidence increased significantly among young, black/African American MSM. In 2009, MSM accounted for 61% of new infections, heterosexual contact 27%, injection drug use (IDU) 9%, and MSM/IDU 3%. Conclusions/Significance Overall, HIV incidence in the United States was relatively stable 2006–2009; however, among young MSM, particularly black/African American MSM, incidence increased. HIV continues to be a major public health burden, disproportionately affecting several populations in the United States, especially MSM and racial and ethnic minorities. Expanded, improved, and targeted prevention is necessary to reduce HIV incidence

A note on moments of variables summing to normal order statistics

This article derives means, variance--covariance matrices of concomitant vectors corresponding to normal order statistics. These results generalize the earlier work from the independent case to the correlated case. We also derive the covariance matrices of the concomitant vectors. All results are neatly expressed in matrix form with meaningful interpretation.Concomitants moments multivariate normal order statistics

A census tract-level examination of social determinants of health among black/African American men with diagnosed HIV infection, 2005-2009--17 US areas.

HIV disproportionately affects black men in the United States: most diagnoses are for black gay, bisexual, and other men who have sex with men (collectively referred to as MSM). A better understanding of the social conditions in which black men live and work may better explain why HIV incidence and diagnosis rates are higher than expected in this population.Using data from the National HIV Surveillance System and the US Census Bureau's American Community Survey, we examined the relationships of HIV diagnosis rates and 5 census tract-level social determinants of health variables for 21,948 black MSM and non-MSM aged ≥ 15 years residing in 17 areas in the United States. We examined federal poverty status, marital status, education level, employment status, and vacancy status and computed rate ratios (RRs) and prevalence odds ratios (PORs), using logistic regression with zero-inflated negative binomial modeling.Among black MSM, HIV diagnosis rates decreased as poverty increased (RR: 0.54). At the time of HIV diagnosis, black MSM were less likely than black non-MSM to live in census tracts with a higher proportion below the poverty level (POR: 0.81) and with a higher proportion of vacant houses (POR: 0.86). In comparison, housing vacancy was positively associated with HIV diagnosis rates among black non-MSM (RR: 1.65). HIV diagnosis rates were higher for black MSM (RR: 2.75) and non-MSM (RR: 4.90) whose educational level was low. Rates were significantly lower for black MSM (RR: 0.06) and non-MSM (RR: 0.26) as the proportion unemployed and the proportion married increased.This exploratory study found differences in the patterns of HIV diagnosis rates for black MSM and non-MSM and provides insight into the transmission of HIV infection in areas that reflect substantial disadvantage in education, housing, employment, and income

Molecular analysis allows inference into HIV transmission among young men who have sex with men in the United States

ObjectiveThe objective of this study is to understand the spread of HIV among and between age and racial/ethnic groups of men who engage in male-to-male sexual contact (MSM) in the United States.DesignAn analysis of HIV-1 pol sequences for MSM collected through the US National HIV Surveillance System (NHSS) during 2001-2012.MethodsPairwise genetic distance was calculated to determine potential transmission partners (those with very closely related nucleotide sequences, i.e. distance ≤1.5%). We described race/ethnicity and age of potential transmission partners of MSM.ResultsOf 23 048 MSM with HIV sequences submitted to NHSS during 2000-2012, we identified potential transmission partners for 8880 (39%). Most potential transmission partners were of the same race/ethnicity (78% for blacks/African-Americans, 64% for whites and 49% for Hispanics/Latinos). This assortative mixing was even more pronounced in the youngest age groups. Significantly fewer young black/African-American and Hispanic/Latino MSM had older potential transmission partners than young white MSM.ConclusionBlack/African-American MSM, who are more profoundly affected by HIV, were more likely to have potential HIV transmission partners who were of the same race/ethnicity and similar in age, suggesting that disparities in HIV infections are in large part not due to age-disassortative relationships. Concerted efforts to increase access to preexposure prophylaxis, quality HIV care and effective treatment are needed to interrupt transmission chains among young, black/African-American MSM

Identifying the Impact of Social Determinants of Health on Disease Rates Using Correlation Analysis of Area-Based Summary Information

Area-based measures of socioeconomic variables can be used to identify risk factors associated with a disease of interest. When correlation analysis is used to identify risk factors, potential confounding from other variables must be taken into account

Diagnoses of HIV infection among black/African American MSM and non-MSM, by age at diagnosis, 2005–2009—17 areas.

<p>Note. Data include persons with diagnosed HIV infection regardless of stage of disease at diagnosis. HIV diagnosis data were statistically adjusted for missing transmission category, but not for reporting delays or incomplete reporting.</p><p>MSM, men who reported ever having had sexual contact with other men.</p>a<p>Rates are per 100,000 population.</p><p>Diagnoses of HIV infection among black/African American MSM and non-MSM, by age at diagnosis, 2005–2009—17 areas.</p