This paper describes the reasons for missing scheduled visits and the influence of phone reminders on missing visit in the ANRS-PEDIACAM cohort from April 2014 to April 2017; which is an ongoing longitudinal study set up for more than ten years. Also, the influence of phone reminders on missing visit state, from inclusion to April 2017 was modelled using discrete time multistate framework characterized by: retention to the care; duration of consecutive missing scheduled visit and mortality.
Overall, about 45% of children followed had been considered NC at least once during the evaluation period. The proportion of NC was significantly higher (56%) among HIV-uninfected children particularly among HEU-children (58%). This observation reinforces those reported by Sidze et al (22) in a previous study conducted in the same cohort which showed that the proportion of lost to follow up children was significantly lower in HIV-infected and HEU-children compare to HUU-children, and only 35% of the latter could be joined by phone calls. The high proportion of NC among HIV-uninfected children might be related to parent decision. As a longitudinal study, PEDIACAM has consisted of regular clinical visits. The parents whose child is not sick, or shows no signs of illness, may not perceive the importance of regular clinical visits and will even try to stop follow-up as was observed in 90.6%(29/32) of those who show interest to stop. On the other hand, a high proportion of mothers (42%) of HEU-children were unaware of their HIV status before prenatal HIV screening. The Woman who had not disclosed her own HIV infection status to the family (especially her partner) had difficulties justifying frequent visits with the child to the health facility. Fear of violence and stigma from their families prevented them from utilizing HIV care services (23).
In this study, phone calls reminder had considered as a search tool on returning to care. The influence of this intervention in improving patient adherence in health facilities had been shown in a similar context (16, 17, 24). Only 35.2% of the total phone calls made resulted in a phone interview. The reasons for NC to missed visits were mainly related to geographic mobility of population (relocation, travels), lack of time, and forgetfulness. These reasons are similar to those presented in other study (25). However, in our study, others important reasons like stigma, lack of money, and the cost of transport were not mentioned as indicated in some studies conducted in the resource’s limited countries (22, 25–28). In fact, in PEDIACAM study, to avoid missing scheduled visits, free medical support and reimbursement of transport fares were brought to the children. This is curious when we find that it’s the uninfected children who miss the most visits, and that is why we can think that this stigma reason could have been masked among the answer we collected.
The predominance of relocation (30.4%) among reasons given in our study could be explained by people dynamic related to study duration. Some of the parents were transferred for professional purpose, others relocated because of economic reasons or modification of the composition of the family with the death of one of the parents. Most of the parents who change the place of residence had children always NC indicating that specific measures should be implemented to tackle such a problem.
Phone call reminders (CR) allowed to reduce significantly adjusted relative risk to miss one scheduled visit to two third. This result shows that CR are an effective intervention to improve the retention in care. Our results are in line with those recently published in a systematic review of current clinical evidence of CR on retention to care among HIV patients (29). The later used the results from nine studies carried out in four sub-Saharan African countries (Cameroon, Kenya, South Africa, Eswatini), Switzerland, United Kingdom and United States of America. However, this intervention shows weaknesses for children non-compliant. Indeed, a large number of calls performed among non-compliant children remained unreachable throughout the study period.
Multivariate analysis identified others economically and individual’s factors associated with a missing visit or non-compliant: HIV infection, low family incomes, mother’s occupation. In addition, low-income family live in a precarious situation, which leads to frequent relocation to find a better situation or for seasonal work. This may result in an increase in the distance from the site of care, an increase in the cost of transport and therefore pre-financing difficulties. On the other hand, most of the mothers (40%) of HEU-children were housewives or unemployed at the inclusion of their child in the study. However, it can be noted that mothers who were housewives or unemployed were not financially independent and therefore needed financial support from a partner or their families to come frequently to clinical visits.
This study has some limitations: the phone calls were the only research tool used in this study for reminders and collection of informations about the reasons for missing visits. More than half of calls performed were unreachable. As a result, reasons for missing visits were not always available, and could only be collected from those who were reachable. The time intervals between clinical visits were irregular throughout the follow-up. In multivariate analysis, we only considered covariables measured at inclusion in our study. Indeed, the model was the concern with missing visits, and at these visits, the dynamic data were missing. In this context, the modeling requires a step of the imputation of the missing data beforehand. In a recent paper, Lee and al (21) used a most recent observed value for imputing missing data, however this strategy to deal with missing data is not always appropriate. In future work, comparing this method with other imputation strategies may determine the best way to consider dynamic data in this framework.