Bayesian estimation of a cancer population by capture-recapture with individual capture heterogeneity and small sample

Size of the Adult HIV-Infected Population Adjusted for the Unreported AIDS Mortality in the Santa Catarina State, Brazil, 2008-2017

OBJECTIVE

To estimate the number of 15-79-year-old individuals infected with HIV in the Santa Catarina state, Brazil, during the period 2008-2017.

METHODS

Three official registers of the HIV-infected individuals were compiled: SINAN for the HIV/AIDS epidemiological surveillance, SIM for mortality and SISCEL for the HIV viral load and CD4/CD8 cell count. Their records were linked by a unique personal identifier. Capture-recapture estimates were obtained by log-linear modelling with both the main effects and interaction between the registers, adjusted for age, sex and period. An adjustment for underreporting of AIDS-related deaths used published data on ill-defined causes of death and AIDS mortality.

RESULTS

After data sorting, 67340 HIV/AIDS records were identified: 29734 (44.2%) by SINAN, 5540 (8.2%) by SIM and 32066 (47.6%) by SISCEL. After record linkage, the HIV population size was estimated at 45707, whereas the capture-recapture method added 44 individuals. The number of new HIV/AIDS notifications per year increased significantly in 2014-2017 compared to the period 2011-2013 among 15-34-year-old men and less so for older men and women. Including 1512 unreported AIDS-related deaths gave an estimated 47263 HIV-infected individuals with 95% confidence interval (CI) of 47245-47282 and corresponding incidence of 93 (95% CI 91-96) p/100000. Case ascertainment of 62.9%, 78.5% and 67.8% was estimated for SINAN, SIM and SISCEL, respectively.

CONCLUSION

Three major HIV/AIDS registers in Brazil showed significant under-notification of the HIV/AIDS epidemiological surveillance amenable to significant improvement by routine record linkage.

Alzheimer's disease: Estimating its prevalence rate in a French geographical unit using the National Alzheimer Data Bank and national health insurance information systems

Background

Reliable epidemiological data on Alzheimer's disease are scarce. However, these are necessary to adapt healthcare policy in terms of prevention, care and social needs related to this condition. To estimate the prevalence rate in the Alpes-Maritimes on the French Riviera, with a population of one million, we present a capture-recapture procedure applied to cases of Alzheimer’s disease, based on two epidemiological surveillance systems.

Methods

To estimate the total number of patients affected by Alzheimer's disease, a capture-recapture study included a cohort of patients with Alzheimer's disease or receiving medications only eligible for use for this condition, recorded by a specific health insurance information system (Health Insurance Cohort, HIC), and those registered in the French National Alzheimer’s Data Bank (“Banque Nationale Alzheimer”, BNA) in 2010 and 2011. We applied Bayesian estimation of the M_t ecological model, taking into account age and gender as covariates, i.e. factors of inhomogeneous catchability.

Results

Overall, 5,562 patients with Alzheimer's disease were recorded, of whom only 856 were common to both information systems. Mean age and F/M sex ratio differed between BNA and HIC surveillance systems, 81 vs 84 years and 2.7 vs 3.2, respectively. A Bayesian estimation, with age and gender as covariates, yields an estimate of 15,060 cases of Alzheimer's disease [95%HPDI: 14,490–15,630] in the Alpes-Maritimes. The completeness of the HIC and BNA databases were respectively of 25.4% and 17.2%. The estimated prevalence rate among the population over 65 years old was 6.3% in 2010–2011.

Conclusions

This study demonstrates that it is possible to determine the number of subjects affected by Alzheimer's disease in a geographical unit, using available data from two existing surveillance systems in France, i.e. 15,060 cases in the Alpes-Maritimes. This is the first stage of a population-based approach in view of adapting available resources to the population’s needs.

Mortality patterns and risk among older men and women with intellectual disability: a Swedish national retrospective cohort study

Background

Sweden has closed all institutions and imposed legislation to ensure service and support for individuals with intellectual disability (ID). Understanding mortality among older individuals with ID is essential to inform development of health promotion and disease control strategies. We investigated patterns and risk of mortality among older adults with ID in Sweden.

Methods

This retrospective cohort study compared older adults aged 55 years and older with ID with a control population. Participants were followed during 2002–2015 or death, and censored if they moved out of Sweden. Individuals with ID were identified from two national registers: one covering all specialist health-care visits (out-patient visits and hospitalisation) and the other covering people accessing social/support services. Individuals with ID (n = 15,289) were matched with a control population by sex, birth year, and year of first hospitalisation/out-patient visit/access to LSS services. Cause-of-death data were recorded using International Classification of Diseases, Tenth Revision. Cox proportional hazards regression were conducted to assess if overall and cause-specific mortality rate among individuals with ID was higher than in the Swedish population.

Results

The overall mortality rate among individuals with ID was 2483 per 100,000 people compared with 810 in the control population. Among those who died, more individuals with ID were younger than 75 years and unmarried. Leading causes of death among individuals with ID were circulatory diseases (34%), respiratory diseases (17%) and neoplasms (15%). Leading causes of death in a sub-sample with Down syndrome (DS) were respiratory diseases (37%), circulatory diseases (26%) and mental/behavioural disorders (11%). Epilepsy and pneumonitis were more common among individuals with ID than controls. Alzheimer’s disease was common in the control population and individuals with DS, but not among those with ID when DS was excluded. Individuals with ID had a higher overall mortality risk (hazard ratio [HR] 4.1, 95% confidence interval [CI] 4.0–4.3) and respiratory disease death risk (HR 12.5, 95% CI 10.9–14.2) than controls.

Conclusion

Older adults with ID in Sweden carry a higher mortality risk compared with the general population, mainly attributable to respiratory, nervous and circulatory diseases. Care for this group, particularly during the terminal stage of illness, needs to be tailored based on understanding of their main health problem.

Electronic supplementary material

The online version of this article (10.1186/s12877-017-0665-3) contains supplementary material, which is available to authorized users.

Looking Beyond Respiratory Cultures: Microbiome-Cytokine Signatures of Bacterial Pneumonia and Tracheobronchitis in Lung Transplant Recipients

Bacterial pneumonia and tracheobronchitis are diagnosed frequently following lung transplantation. The diseases share clinical signs of inflammation and are often difficult to differentiate based on culture results. Microbiome and host immune-response signatures that distinguish between pneumonia and tracheobronchitis are undefined. Using a retrospective study design, we selected 49 bronchoalveolar lavage fluid samples from 16 lung transplant recipients associated with pneumonia (n = 8), tracheobronchitis (n = 12) or colonization without respiratory infection (n = 29). We ensured an even distribution of Pseudomonas aeruginosa or Staphylococcus aureus culture-positive samples across the groups. Bayesian regression analysis identified non-culture-based signatures comprising 16S ribosomal RNA microbiome profiles, cytokine levels and clinical variables that characterized the three diagnoses. Relative to samples associated with colonization, those from pneumonia had significantly lower microbial diversity, decreased levels of several bacterial genera and prominent multifunctional cytokine responses. In contrast, tracheobronchitis was characterized by high microbial diversity and multifunctional cytokine responses that differed from those of pneumonia-colonization comparisons. The dissimilar microbiomes and cytokine responses underlying bacterial pneumonia and tracheobronchitis following lung transplantation suggest that the diseases result from different pathogenic processes. Microbiomes and cytokine responses had complementary features, suggesting that they are closely interconnected in the pathogenesis of both diseases.