Adjusting HIV prevalence data from a program for the prevention of mother-to-child transmission for surveillance purposes in Uganda.
OBJECTIVE
To evaluate a method for adjusting estimates of HIV prevalence based on data from a program for the prevention of mother-to-child transmission (PMTCT) of HIV infection for the potential bias attributable to refusal of PMTCT-related testing.


METHODS
Age-specific logistic regression models were used to estimate the HIV risk coefficients for 10 predictor variables among women who accepted the PMTCT-related testing (n = 1874) at an antenatal clinic in northern Uganda. These risk coefficients were used to predict the prevalence among women who were not tested (n = 1719) and to adjust the PMTCT-based prevalence for nonparticipation bias. Crude and adjusted PMTCT-based prevalence estimates were compared with the prevalence among women who were anonymously tested as part of routine sentinel surveillance (n = 2225).


RESULTS
The PMTCT-based prevalence represented an underestimate compared with that based on anonymous surveillance in 2004 (9.0% vs. 10.5%); in 2005, it constituted an overestimate (11.8% vs. 10.9%). Adjusting the PMTCT-based prevalence reduced the difference attributable to nonparticipation bias by approximately 70% in both years, so that the adjusted prevalence (10.1% in 2004 and 11.2% in 2005) was similar to the surveillance-based prevalence.


CONCLUSIONS
The adjustment method was effective in reducing the nonparticipation bias. Further studies are needed to assess the utility of PMTCT program data for HIV surveillance.
Fabiani
Massimo
M
National Centre for Epidemiology, Surveillance, and Health Promotion, Istituto Superiore di Sanità, Rome, Italy. massimo.fabiani@iss.it
Yoti
Zabulon
Z
Nattabi
Barbara
B
Ayella
Emintone O
EO
Opio
Alex A
AA
Musinguzi
Joshua
J
García Calleja
Jesús M
JM
Declich
Silvia
S
D000328:Adult; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000517:prevention & control; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D015588:Observer Variation; D010342:Patient Acceptance of Health Care; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000517:prevention & control*; D015995:Prevalence; D016312:Treatment Refusal; D014454:Uganda / Q000453:epidemiology