Estimating the number of HIV-infected injection drug users in Bangkok: a capture--recapture method.

Abstract

OBJECTIVES. The purpose of the study was to estimate the number of injection drug users infected with the human immunodeficiency virus (HIV) in Bangkok to allow planning for health services for this population. METHODS. A two-sample capture-recapture method was used. The first capture listed all persons on methadone treatment for opiate addiction from April 17 through May 17, 1991, at 18 facilities in Bangkok. The second capture involved urine testing of persons held at 72 Bangkok police stations from June 3 through September 30, 1991. Persons whose urine tests were positive for opiate metabolites or methadone were included on the second list. RESULTS. The first capture comprised 4064 persons and the recapture 1540 persons. There were 171 persons included on both lists, yielding an estimate of 36,600 opiate users in Bangkok. Existing data indicate that 89% of opiate users in Bangkok inject drugs and that about one third are infected with HIV, yielding an estimate of approximately 12,000 HIV-infected injection drug users in Bangkok in 1991. CONCLUSIONS. During the 1990s the number of cases of acquired immunodeficiency syndrome (AIDS) and other HIV-related diseases, including tuberculosis, in the population of HIV-infected injection drug users in Bangkok will increase dramatically, placing new demands on existing health care facilities. The capture-recapture method may be useful in estimating difficult-to-count populations, including injection drug users.

Hospitalizations for suspected dengue in Puerto Rico, 1991-1995: estimation by capture-recapture methods. The Puerto Rico Association of Epidemiologists.

“…5,7,9,11 The first assumption is that the population in question is closed to migration. Since Puerto Rico has surveillance systems in place throughout the island, and dengue is an acute disease for which patients do not seek hospitalization in the United States, it is unlikely that immigration or emigration affected our results.…”

“…7 The following formulae were used to calculate the variance (var) and 95% confidence interval (CI) for the estimate of N: var (N(est)) ϭ (C1 ϫ C2(C1 Ϫ m)(C2 Ϫ m))/m 3 and 95% CI ϭ N(est) Ϯ 1.96 ͙var(N(est)). 7 Finally, to examine for dependency of data sources, the databases were stratified into cases reported by hospital type (private or public), and the above formulas were used to calculate hospital type-specific estimates of N. These estimates were then summed to determine a stratified estimate of N.…”

“…[5][6][7] Capture-recapture estimations (initially designed to study free-ranging animal populations) compare the results of 2 or more independent surveillance systems for the same event, and by measuring the degree of overlap or duplication between them provide an estimate of the total number of events, and therefore the completeness of ascertainment in each system. 8 Because the method makes use of existing data, it is efficient and cost-effective.…”

Características epidemiológicas de la mortalidad neonatal en el Perú, 2011-2012

“…Se calculó el subregistro de notificación para el SNVEPN aplicándose el método de captura y recaptura (14)(15)(16) ; para ello, se compararon las bases de datos del SNVEPN del año 2011 con los certificados de defunción neonatal del sistema de registro de hechos vitales (SHV), año 2011, pareándose los registros por apellidos, nombres, edad, procedencia y diagnóstico. Se estimó el número de muertes neonatales para cada departamento, de los años 2011 y 2012.…”

Capture-recapture estimates of problem drug use and the use of simulation based confidence intervals in a stratified analysis

“…17 Outside the UK, the European Monitoring Centre on Drugs and Drug Addiction (EMCDDA) funded a study, using three sample capture re-capture methods, to estimate the prevalence of opioid misuse within six European cities for the age group 15-54. 18 Other studies within Europe have estimated the prevalence of drug misuse in Amsterdam, 19 Barcelona, 20 and Berlin, 21 while further afield, capture recapture methods have been used to estimate the prevalence of drug misuse in Michigan, 22 Los Angeles, 23 Bangkok, 24 and Australia. 25 …”