Longitudinal patterns of the relation between anxiety, depression and posttraumatic stress disorder among postpartum women with and without maternal morbidities in Northwest Ethiopia: a cross-lagged autoregressive structural equation modelling

Background: The postpartum period is a time where mothers can undergo significant changes that increase vulnerability for depression, anxiety and posttraumatic stress disorder symptoms. However, the direct and indirect factors of depression, anxiety and posttraumatic stress disorder symptoms and their direction of relationships following childbirth is not well investigated in Ethiopia. The aim of this study was to determine the direct and indirect factors of depression, anxiety and posttraumatic stress disorder symptoms and their direction of relationships following childbirth. Methods: A total of 775 women consented to participate at the first, second and third follow-up of the study (6th, 12th and 18th week of postpartum period) during October, 2020 – March, 2021. Women were recruited after childbirth and before discharge using the World Health Organization maternal morbidity working group criteria to identify exposed and non-exposed groups. A cross-lagged autoregressive path analysis and linear structural equation modelling were carried out using Stata version 16 software. Results: Prevalence rates of anxiety were 18.5%, 15.5% and 8.5% at the 6th, 12th and 18th week of postpartum respectively. The prevalence rates for depression were also found to be 15.5%, 12.9% and 8.6% respectively during the same follow up period and for posttraumatic stress disorder it was found to be 9.7%, 6.8% and 3.5% at the 6th, 12th and 18th week of postpartum respectively. Moreover, anxiety and depression were found to be a causal risk factors for posttraumatic stress disorder in the postpartum period. Direct maternal morbidity, fear of childbirth, higher gravidity, perceived traumatic childbirth and indirect maternal morbidity were found to have a direct and indirect positive association with depression, anxiety and posttraumatic stress disorder. In contrast, higher parity, higher family size and higher social support have a direct and indirect negative association. Conclusion: Postnatal mental health screening, early diagnosis and treatment of maternal morbidities, developing encouraging strategies for social support and providing adequate information about birth procedures and response to mothers’ needs during childbirth are essential to improve maternal mental health in the postpartum period. This study was part of the health facility linked community based prospective follow-up study conducted in Northwest Ethiopia to determine the effect of maternal morbidities on maternal health related quality of life, functional status and mental health problems [29–31]. Postpartum women were recruited in four hospitals of south Gondar zone, Northwest Ethiopia. The data collection took place between October 1, 2020 and March 30, 2021. South Gondar is located at 650 km Northwest from Addis Ababa the capital city of Ethiopia. A total of 775 women consented to participate in the study and participated at the first, second and third follow-up of the study (6th, 12th and 18th week of postpartum period). Recruitment of the study participants was done after child birth and before the time of discharge. Women with any of the direct maternal morbidities were recruited into the exposed group and those without the direct maternal morbidities were into the non-exposed group based on the WHO maternal morbidity criteria [32]. The total sample size was determined by using Epi-Info version 7 with a two-population proportion formula. Hence, a sample size of 779 was obtained by taking 0.05 alpha (α), power of 90%, odds ratio of 4.23, proportion of 2.3%, ratio of 1:3 and by adding 15% non-response rate. These sample size calculation values were obtained from a previous study [24]. Women aged 15 years and above, with preterm, term or post term delivery and with live birth, still birth or fetal death were included in the study. The PTSD criterion A was not considered as an exclusion criterion, because childbirth related negative events and emotions that do not satisfy the criterion A can cause symptoms that could qualify as a PTSD diagnosis [13]. All exposed women with direct maternal morbidity included in the study and non-exposed women without direct maternal morbidities were selected by simple random sampling method using their chart number on daily bases. With 1:2 ratio of exposed to non-exposed mothers, this recruitment procedure continued prospectively until the required sample size was fulfilled. Women were asked for consent to participate in the study and after getting their consent and full address, appointments were made at their home to collect the data for the follow up study. The study participants overall sampling procedure is shown in Fig. 1. A flow diagram chart of study participants sampling procedure The outcome variables were depression, anxiety and posttraumatic stress disorder. The independent variables were; direct maternal morbidities(obstetric hemorrhage, hypertensive disorders, obstructed labour, puerperal sepsis, gestational diabetes mellitus, perineal tear), indirect maternal morbidities (anemia, malaria, hypertension, asthma, tuberculosis, HIV), socio-demographic variables (age, educational status, marital status, religion, ethnicity, occupation, monthly expenditure), obstetric variables (parity, mode of delivery, gestational age at birth, birth weight, birth interval, fetal death, unwanted pregnancies, antenatal care visit, history of abortion), residence and psychosocial factors (social support and fear of child birth). The short version of depression, anxiety and stress scale 21 (DASS-21) questionnaire was used to measure depression, anxiety and stress. The instrument has 21 items with three domains. Each domain comprises seven items assessing symptoms of depression, anxiety and stress. In this study a score ≥ 10 was considered for a mother to have a symptom of depression. A cut-off score of ≥ 8 was considered to have symptoms of anxiety and a score of ≥ 15 was considered to have symptoms of stress. This instrument was used previously in Ethiopia [33, 34]. The childbirth stressor was operationalized by using the Traumatic Event Scale (TES) [35, 36]. In this scale, the items concerning criterion A (stressor) were formulated as follows: Four alternative answers follow each statement: “not at all,” “somehow,” “much,” and “very much.” Criterion A is fulfilled if either of the alternatives “much” or “very much” on item 1, 2 and/or 3, and 4 is marked [35, 36]. After the questions regarding criterion A, we have used the Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5) comprising the 20 PTSD symptoms (criterion B, C, D and E) to measure PTSD. The instrument contains 20 items, including three new PTSD symptoms (compared with the PTSD Checklist for DSM-V): blame, negative emotions and reckless or self-destructive behavior [37]. A total-symptom score of zero to 80 can be obtained by summing the items. A score of 31–33 is optimal to determine PTSD symptoms and a score of ≥ 33 is recommended when further psychometric testing is not available [38, 39]. Therefore, a score of ≥ 33 was considered to have symptoms of PTSD for this study. The instrument was used previously in Ethiopia [39]. The Wijma Delivery Expectation/Experience Questionnaire (W-DEQ) was used to measure fear of child birth. The W-DEQ has been designed specially to measure fear of child birth operationalized by the cognitive appraisal of the delivery. This 33-item rating scale has a 6-point Likert scale as a response format, ranging from ‘ not at all’ (= 0) to ‘ extremely’ (= 5), yielding a score-range between 0 and 165. The Internal consistency and split-half reliability of the W-DEQ was checked in previous studies in Ethiopia with the Cronbach’s alpha score of 0.932 [40, 41]. A score of ≥ 85 was considered to have fear of child birth for this study [40, 41]. The Oslo 3-items social support scale with scores ranging from 3 to 14 was used to measure social support. The social support scores were categorized into poor or no social support for scores less than nine. Scores between 9 and 14 were considered moderate to strong support and merged together as “yes” for social support. The Oslo 3-items social support scale was validated and previously used in Ethiopia [42–44]. Administering baseline questionnaire and diagnosis of direct and indirect maternal morbidities based on the WHO criteria, were done by health professionals working in the Gynecology and Obstetrics wards of the study Hospitals. The questionnaire consisted of a patient interview and record review. The interview was on socioeconomic status, medical and obstetric history and clinical symptoms. The record review was intended to extract information on selected laboratory tests and results for hemoglobin, HIV, malaria (rapid diagnostic test or smear) and glucometer (random blood sugar). The DASS-21 and PCL-5 were administered by health extension workers at the first, second and third home visit (6th, 12th and 18th week of postpartum period). Training was given for data collectors and supervision was done by the principal investigator. During the training process, data collectors carefully reviewed each question and conduct pretest before the study commences. The investigator and data collectors have checked the final version of the questionnaire and update as required based on the pretest. A three-wave cross-lagged autoregressive structural equation modeling was carried out using Stata version 16 software [45]. The Autoregressive Cross-lagged (ARCL) modeling strategy was used to examine the longitudinal relations between PTSD, depression, and anxiety [26, 45, 46]. This modeling strategy incorporates three main components. First, the stability/autoregressive effects (effects of T1 depressive, anxiety and PTSD symptoms on their respective T2 variables). That means, later measures of a construct are predicted by earlier measures of the same construct. Second, the cross-lagged effects (effect of T1 depressive symptoms on T2 PTSD symptoms and of T1 PTSD symptoms on T2 depressive symptoms). That means, earlier measures of depression predict later measures of PTSD. This model can be extended to examine bi-directional relations such that earlier measures of PTSD predict later measures of depression as well. Third, the synchronous associations between the unexplained variances of these variables at T1, T2 and T3 [26, 46]. We estimated the model fitness by using the comparative fit index (CFI), Tucker-Lewis Index (TLI) and the root-mean-square error of approximation (RMSEA). Both the TLI and CFI should be greater than 0.90, but the RMSEA value should be less than 0.08 to judge the model as reasonably fitting the data [13, 46]. The aim of the analysis was to examine the cross-lagged effects of depressive, anxiety and PTSD symptoms, controlling for the confounder variables and stability/autoregressive effects. In addition, the direct and indirect relationships between the independent and dependent variables was also explored using the structural equation modeling. This allowed us to assess the strength of the hypothesized direct and indirect causal pathways. Estimated effects for which p < 0.05 were considered as being statistically significant. This study was approved by the institutional review board of Bahir Dar University. Each study participant has given written informed consent before participating in the study. Assent was also obtained from teenage mothers whose age is less than 18 years, in addition to informed consent from their care givers. Using codes, passwords and limiting access to the data only for the investigators were the measures taken to ensure the confidentiality of the data. Data collectors read out and assisted participants to fill out the consent form if participants were unable to read and write.