Lost to follow up is a major challenge in PMTCT program which leads advanced stage of HIV, increases maternal HIV/AIDS related morbidity and mortality, enables the vertical transmission of HIV to newborn and facilitates the development of drug resistance, missed opportunities to family planning(40). Nationally, there was a target for fulfilling 90-90-90 strategy as percentage of currently receiving antiretroviral therapy among all adults and children living with HIV to be 90% which is to decrease LTFU to less than 10% (5). Therefore, this retrospective record review was conducted to determine the incidence and predictors of LTFU among pregnant and breast-feeding women on Option B+ PMTCT program at Gondar university comprehensive specialized hospital.
The overall incidence density of LTFU in the current study was 9.4 per 1000 person-months by the end of PMTCT follow-up time. This finding is agreed with previous study conducted in Nekemte Hospital, western Ethiopia ( 9 per 1000 person-months observations) (30). This is due to the similarity in study time at which nationally different strategies were adopted to increase ART coverage and adherence. Among these, ART drug refill and clinical follow-up, including laboratory investigation, took place in advance at ART/PMTCT clinic. In addition, Case managers, who are trained lay workers and most of whom are PLHIV, provide adherence and psychosocial services at these ART health facilities in order to decrease interruption from services(44, 45). On the other hand, this finding is lower than studies reported from Northeast Ethiopia (14.8 per 1000 person-months observations) (29). This difference might be due to the difference in the study time that the study was initiated. The current study includes the recent year data at which most strategies as a country level were implemented to decrease LTFU like bringing services closer to communities by expanding ART sites to above 1,500 Health facilities, increasing service provision by expanding trained health personnel in order to decrease waiting times at the facility than the previous study(2013, 2014 and 2015).The variation could also be explained by the difference in study setting, since this study was conducted at one referral hospital whereas, a study conducted in Northeast Ethiopia was done in four hospital and ten health centers. Studies showed that magnitude of lost to follow up varied according to level of health institutions(23, 29). Moreover, the lower incidence of LTFU in the current study might be due to the fact that different programs/measures were implemented in the country in recent years to decrease the rate of LTFU among HIV infected women. Among these measures, increasing trained human power including midwives, frequent follow-up schedule and better drug preparation (fixed dose ART treatment) by giving better consideration for mothers to implement the program effectively(40). The current study finding is also lower than studies conducted in different African countries such as Uganda(15, 16, 18), South Africa(24), Malawi(14, 46) and Kenya(19).This discrepancy might be due to the difference in study time, operational definition of the outcome variable, and characteristic of study participants. For example, the study period for a study conducted in Malawi was 3-years record review(14) whereas the current study incorporated recent years’ data which had better improvement ART coverage. Another explanation for discrepancy of incidence rate was characteristics of study participants that the study in Uganda incorporated 92% of the population with rural place of residence(16) compared to only 38.5% in the current study. The operational definitions of studies in Kenya and south Africa (28,33) were missing 6 months till last follow up visits compared to three months to the current study. Furthermore, the rate of LTFU on the current study was lower than the study done in Myanmar which was 7 per 1000 person-years(11). This difference might be due to the reason that study in Myanmar included only pregnant women. Pregnancy related symptoms and signs during ante-natal care clinics (ANC) follow-up have chance of dropping out from the PMTCT clinic(47).
The current study showed that risk of LTFU among women who are residing in rural area is higher as compared to women residing in urban. Supportive findings were reported from previous studies in Ethiopia and Brazil(10, 30, 48). Possible explanations for this might be remote area mothers are forced to travel long distances in order to get the nearest hospital, which necessarily involves high costs which leads LTFU(16) and cannot easily get transport services due to poor /lack of road construction, makes women to walk long distances by bare foot, this leads them less likely to adhere to option B+ strategy (31) and resulting in missing the appointments(15, 32). This justification is also supported by the report given that lack of access to health care service leads to poor adherence and LTFU to option B+ PMTCT drugs (15). Although the current study did not assess this, additional explanation for high risk of LTFU that in a rural setting transport is costly because most mothers are farmers and housewife with low socioeconomic status(16).
This study also found that women who had no baseline viral load measurement were more likely to be LTFU as compared with those who had baseline viral load measurement within three-month of PMTCT enrollment. This finding is supported by a study in Nigeria among general population which was missing viral load measurement affects LTFU(49). This might be due to the fact that when viral load measurement took during PMTCT enrolment, the health care provider classified women as high risk with viral load more than 1000 copies/mm3 and low risk with viral load less than 1000copies/mm3. Therefore, those with high risk category will be followed carefully and frequently in order not miss the appointment time since it is a gold criteria to knew the women with a good way/ adherence in service provision(40). Another possible explanation for the high rate of LTFU for those who had no baseline viral load measurement is that viral load measurement implemented in advance after 2016 in Ethiopia. Another possible explanation could be that taking viral load measurement at the baseline raises women’s HIV-related literacy and awareness and might engage women in care(45).
Moreover, women who had a fair/poor drug adherence level were more likely to be LTFU compared to women who had a good adherence level. This finding is supported by the study conducted in previous studies in Ethiopia(48) and in Malawi (22).This might be due to the fact that poor adherence to drugs is due to the feared side effects resulting in stopping taking ART treatments and lack of knowledge towards the importance of adherence to all appointments lead stopping/missing the schedule of ART treatment(18).
The current study revealed that risk of LTFU for those women who started ART at the same day following HIV diagnosis was higher than those women who started ART latter following HIV diagnosis. This finding is agreed with studies done in Northeast Ethiopia(29) and in Malawi (20).This might be due to the need of sufficient time and information for clients to adjust and preparing themselves lifetime treatment psychologically, socially and physically. Moreover, the reason for lost follow-up for those women who started in the same day initiation might be due to the combined effect of ART side effects at the time of initiation and pregnancy induced physiological side effects such as; regurgitation, nausea and vomiting leads loss in treatment follow-up. But the study in southern Ethiopia suggests that pregnant women who started ART at the time of HIV diagnosis were more likely to adhere to option B+ ART resulting in increasing retention in HIV care(31) which is against of the finding of this study. The current study is also against to the study in south Africa which showed that same day antiretroviral therapy initiation in pregnancy is not associated with engagement in care(37).This might be due to the difference of study participants in which study in south Africa included only pregnant women.
The risk of LTFU among women who were on ART before PMTCT enrolment was lower than those who enrolled newly to PMTCT. This finding agreed with studies done in in different countries in African region(19, 23, 30). The possible explanations for this might be a known HIV woman and on ART before enrolment had experienced with ART treatment and might have good awareness about ART treatment, drug side effects and drug adherence than a newly enrolled woman. Evidence also showed that a new HIV diagnosis during routine ante-natal screening can be attended by different degrees of shock and denial and may lead to difficulty accepting immediate initiation of lifelong treatment resulting in lost to follow-up(46). This study also supported previous study done in south Africa which stated that being newly diagnosed with HIV were positively significant predictors of disengagement to ART treatment(24).
The finding of the current study also revealed that women who had recent ART side effects during PMTCT follow-up had a higher risk of LTFU than those women who had not ART side effects. The finding of this study supported by the study in Uganda(16) and in Malawi(9, 26, 33).This might be due to less counselling towards side effects of ART, and less support for women experiencing challenges with tolerability, including options to switch regimens(24).
All in all, incidence rate of LTFU was higher in the last month of PMTCT follow up period which gives implication that lack of proper linkage and referral systems between PMTCT services and ART clinics. In addition, in contrary to the current study, variables like educational status, maternal age, and baseline CD4 cell count showed statistically significant association with LTFU among HIV infected women under PMTCT services in the previous studies conducted at different African countries(15, 23, 24, 26, 29, 33). However, these variables are not statistically significant in the current studies. This difference might be due to the fact that predictors of LTFU varied from one geographical area to another geographical area due to the differences in the economic status of the study participants and infrastructure in the health facilities.
Although our study has its own strength to assess incidence of lost to follow-up (LTFU), it is not free from limitations and should be considered before interpreting results. First, as we conducted through the reviewing of records, we didn’t include important predictors of LTFU like stigma, distance to Hospital, social support. Second, since this study was conducted only in one hospital it may not enough to generalize to all health facilities in Northwest Ethiopia.