The EPDS is a simple, valid and effective screening scale for detection of postpartum depression among postpartum mothers in an urban and peri-urban primary care setting serving the rural community with high postpartum depression prevalence. We found an overall PPD prevalence of 29.5% using the Edinburgh Postnatal Depression scale (EPDS) at a cutoff point of ≥ 10 and this was comparable with a prevalence of 26.5% as determined by the MINI 7.0.2. The PPD prevalence rate determined by these scales falls within the same range with results of various studies in African countries such as South Africa (31.7%) (26), Zimbabwe (33%) (11), and Nigeria (22.9%) (27). Other studies in Africa have however reported a much lower prevalence rate of 12% in Tanzania (28), 9.2% in Sudan (23) and 13% in Kenya (29). Although all these studies used EPDS scale, it is difficult to compare results of the current study with the above studies because of the variations in the PPD prevalence potentially due to the different categories of postpartum women, sample sizes used, cutoff points, reference scales and timeframe of assessment with regard to their risk of PPD. Having excluded women with the most important risk factors for postpartum depression from this research, could also reach prevalence values higher than 26.5% as determined by the MINI 7.0.2. These results therefore imply that in the if the general Ugandan population of postpartum women is subjected to the EPDS, about half of them may be found to be suffering from PPD.
A cut off point for a local setting like Uganda is essential for accurate detection and PPD burden estimation. As such, the present study confirmed that a cutoff point of ≥ 10 as the suitable cutoff point for the EPDS which is similar to the cutoff identified in the original English version by (3). These findings are also in the same range with cutoff points reported by other validation studies in African countries such as Ghana ≥ 10 (30), Zimbabwe ≥ 10 (11). However, the cutoff point established by this study was higher than related studies carried out in Nigeria ≥ 8) (31), and Ethiopia ≥ 5 (32). The variation between the present study and other validation studies in Africa is attributed to diversity in economic circumstances, socio-cultural norms and the heterogeneous nature of study populations. It is particularly important to choose accurate psychometric property findings in a low-income setting as they may not place a burden on the health service through an overly high false-positive rate.
The sensitivity, specificity, positive predictive value and negative predictive value of the EPDS was established by this study to be 86.8%, 92.1%, 80.5% and 94.9% respectively. The sensitivity between 80 and 90% is considered to have good diagnostic performance meaning that the EPDS can correctly identify women who are suffering from postpartum depression, hence in this population the EPDS provides good sensitivity. Similarly, specificity of 92.1% is also considered quite good to correctly identify women who do not have postpartum depression. In addition, the study stratified mothers according to the health facility and age category to compare the psychometric properties of the EPDS across variables and to also ensure generalizability of the findings. The level of accuracy of this scale is comparable and within this sample no statistically significant variations occurred even when stratified. Therefore, the EPDS is identified as a valid scale in measuring postpartum depression in the Ugandan context in this study sample. These study findings are consistent with data from other validation studies in low resource settings where EPDS has been validated in local languages in similar demographically representative settings. For example, systematic reviews reported strong reliability and validity of EPDS for detecting perinatal common disorders among women in low and lower-middle income countries (11, 12, 23). The high sensitivity test reveals that the index scale can establish that there are few false negative results, and thus fewer cases of disease are missed. This also applies to the high specificity revealed as this is important for ruling in disease or mothers with PPD (33). In low-resource settings like Uganda, the strength of the EPDS lies in its high NPV, meaning that with negative results there is high level of confidence that women are free from PPD. The acceptable sensitivity and specificity findings will help in the identification of Ugandan postpartum women at risk of depression.
The present study carried out a nonparametric analysis of the ROC which yielded an area under the curve of 0.89 for Bwizibwera HCIV, 0.97 for Kinoni HCIV and 0.84 for MRRH, implying that the EPDS can effectively distinguish between postpartum mothers who are truly depressed and those women who are not depressed at the cutoff point of ≥ 10.
Strengths and Limitations
The strength of our study is that it was conducted in an urban and peri-urban setting that serves the rural population. Although some studies had utilized this scale in screening for PPD without validation to the Ugandan population (34), this is the first study that translated and established the accuracy of the EPDS in screening mothers with PPD in Uganda. An important limitation of this study was not including women receiving postpartum services from the private clinics and the general population of postpartum women therefore it may not be generalized to this population as it is likely to be higher than the current findings. In addition, this study only focused on the current episode of major depression without assessing for the past episodes of depression as the EPDS only considers the current depression. Not including past episodes of depression does not inform us whether the mothers had depression before the postpartum period but this limitation could be overcome in future studies. In addition, by recruiting women attending health facilities, we may have missed women who do not utilize these services. They could be more prone to PPD. Women who do not attend postpartum services in a health facility setting are more likely to have postpartum check-ups with midwives in their neighborhoods. Village midwives could be a great asset in locating these types of women in future studies. The authors also used a wide precision gap of 0.09 which is the upper limit in order to target a smaller recruitment given the unpredictable timing of the covid-19 pandemic during data collection.
Implications and Recommendations
Screening for postpartum depression should be integrated into routine postpartum care in areas with high PPD prevalence. By routinely using the EPDS to screen mothers with PPD, the awareness of health care providers can improve early detection of postpartum depression. In turn this can lead to positive health outcomes for both mothers, babies and their families, which is an important goal of health care provision and promotion. In addition, incorporating PPD screening in the nursing-midwifery education curricular may be impactful.
This scale may also be validated in postpartum women living with HIV and antepartum mothers suffering from antepartum depression as this may increase the chances of identifying PPD at an early phase. Midwives, nurses, traditional birth attendants, family health practitioners and other primary health care workers can easily apply this screening scale and be encouraged to refer women suspected to have PPD to health facilities for further evaluation. This will ensure that most cases of PPD do not go undetected and untreated.
There is an urgent need for a better understanding of a feasibility study and acceptability study or survey of routine screening of postpartum women utilizing the validated EPDS in south western Uganda to provide appropriate support most especially during this pandemic period when depression is at a high rise.