Reducing lost to follow-up in a large clinical trial of prevention of mother-to-child transmission of HIV: The Breastfeeding, Antiretrovirals and Nutrition study experience
Authors: Sellers Christopher J , Lee Hana , Chasela Charles , Kayira Dumbani , Soko Alice , Mofolo Innocent , Ellington Sascha , Hudgens Michael G , Kourtis Athena P , King Caroline C , Jamieson Denise J , van der Horst Charles ,   on behalf of the BAN Study Team, Adair Linda , Ahmed Yusuf , Ait-Khaled Mounir , Albrecht Sandra , Bangdiwala Shrikant , Bayer Ronald , Bentley Margaret , Bramson Brian , Bobrow Emily , Boyle Nicola , Butera Sal , Chasela Charles , Chavula Charity , Chimerang’ambe Joseph , Chigwenembe Maggie , Chikasema Maria , Chikhungu Norah , Chilongozi David , Chiudzu Grace , Chome Lenesi , Cole Anne , Corbett Amanda , Corneli Amy , Dow Anna , Duerr Ann , Eliya Henry , Ellington Sascha , Eron Joseph , Farr Sherry , Ferguson Yvonne Owens , Fiscus Susan , Flax Valerie , Fokar Ali , Galvin Shannon , Guay Laura , Heilig Chad , Hoffman Irving , Hooten Elizabeth , Hosseinipour Mina , Hudgens Michael , Hurst Stacy , Hyde Lisa , Jamieson Denise , Joaki George , Jones David , Jordan-Bell Elizabeth , Kacheche Zebrone , Kamanga Esmie , Kamanga Gift , Kampani Coxcilly , Kamthunzi Portia , Kamwendo Deborah , Kanyama Cecilia , Kashuba Angela , Kathyola Damson , Kayira Dumbani , Kazembe Peter , King Caroline C. , Knight Rodney , Kourtis Athena P. , Krysiak Robert , Kumwenda Jacob , Lee Hana , Loeliger Edde , Long Dustin , Luhanga Misheck , Madhlopa Victor , Majawa Maganizo , Maida Alice , Marcus Cheryl , Martinson Francis , Thoofer Navdeep , Matiki Chrissie , Mayers Douglas , Mayuni Isabel , McDonough Marita , Meme Joyce , Merry Ceppie , Mita Khama , Mkomawanthu Chimwemwe , Mndala Gertrude , Mndala Ibrahim , Moses Agnes , Msika Albans , Msungama Wezi , Mtimuni Beatrice , Muita Jane , Mumba Noel , Musis Bonface , Mwansambo Charles , Mwapasa Gerald , Nkhoma Jacqueline , Parker Megan , Pendame Richard , Piwoz Ellen , Raines Byron , Ramdas Zane , Rublein John , Ryan Mairin , Sanne Ian , Sellers Christopher , Shugars Diane , Sichali Dorothy , Snowden Wendy , Soko Alice , Spensley Allison , Steens Jean-Marc , Tegha Gerald , Tembo Martin , Thomas Roshan , Tien Hsiao-Chuan , Tohill Beth , van der Horst Charles , Waalberg Esther , Widen Elizabeth , Wiener Jeffrey , Wilfert Cathy , Wiyo Patricia , Zgambo Innocent , Zimba Chifundo 
Published: December 2014

Background/Aims Retaining patients in prevention of mother-to-child transmission of HIV studies can be challenging in resource-limited settings, where high lost to follow-up rates have been reported. In this article, we describe the effectiveness of methods used to encourage retention in the Breastfeeding, Antiretrovirals, and Nutrition study and analyze factors associated with lost to follow-up in the study. Methods The Breastfeeding, Antiretrovirals, and Nutrition clinical trial was designed to evaluate the efficacy of three different mother-to-child HIV transmission prevention strategies. Lower than expected participant retention prompted enhanced efforts to reduce lost to follow-up during the conduct of the trial. Following study completion, we employed regression modeling to determine predictors of perfect attendance and variables associated with being lost to follow-up. Results During the study, intensive tracing efforts were initiated after the first 1686 mother–infant pairs had been enrolled, and 327 pairs were missing. Of these pairs, 60 were located and had complete data obtained. Among the 683 participants enrolling after initiation of intensive tracing efforts, the lost to follow-up rate was 3.4%. At study’s end, 290 (12.2%) of the 2369 mother–infant pairs were lost to follow-up. Among successfully traced missing pairs, relocation was common and three were deceased. Log-binomial regression modeling revealed higher maternal hemoglobin and older maternal age to be significant predictors of perfect attendance. These factors and the presence of food insecurity were also significantly associated with lower rates of lost to follow-up. Conclusion In this large HIV prevention trial, intensive tracing efforts centered on reaching study participants at their homes succeeded in finding a substantial proportion of lost to follow-up participants and were very effective in preventing further lost to follow-up during the remainder of the trial. The association between food insecurity and lower rates of lost to follow-up is likely related to the study’s provision of nutritional support, including a family maize supplement, which may have contributed to patient retention.