Early discharge and risk for postnatal depression

Abstract

MJA 1997; 167: 244-247  

Introduction

Women's desire for early discharge has fitted in well with the financial constraints put upon health care systems; reduced length of stay is seen as desirable because it reduces the cost of obstetric care. Postpartum studies have reported early-discharge programs to be a safe, cost-effective and satisfying alternative to the standard length of hospital stay among low-risk mothers and their infants.^1-5 While these studies have shown that early discharge has no adverse physical effects, the only psychological effects examined have been women's satisfaction about making a choice or taking control of discharge rather than psychological morbidity.^5,6

As postnatal depression is a common disorder which may have a long-term impact on the mother and her infant,⁷ the psychological outcome after childbirth is increasingly being recognised as important.⁸ Postnatal depression is associated with psychosocial factors, such as an excess of adverse life events, lack of social support, dysfunctional personality style and a past history of depression.^8,9 Obstetric factors, such as emergency caesarean section, have also been implicated,^10,11 but the impact of early discharge has not been extensively examined.

The aim of our study was to investigate whether early discharge following childbirth had an effect on the development of postnatal depression in a heterogeneous sample of women.  

Methods

Subjects

Survey instruments

A nine-item personality scale was included that identified different personality traits, scored on a 5-point Likert scale. Factor analysis of this personality scale identified "vulnerable" and "resilient" personality dimensions. The vulnerable personality dimension included being a worrier, nervy, timid and unassertive, sensitive, liable to emotional outbursts and needing to do things right. This scale is reliable (Cronbach α= 0.75), and is associated with increased risk for postnatal depression (Boyce P M, Hickey A R, Greenstock J A and Talley N J, Nepean Hospital, unpublished data).

Interview: A semi-structured interview (conducted by A R H) was used to assess obstetric history, satisfaction with the labour, whether the delivery was congruent with expectations, the quality of the woman's social support, her personal and family psychiatric history, and the quality of her intimate relationships. We also obtained obstetric details from the labour ward computerised database.

Edinburgh Postnatal Depression Scale (EPDS):¹³ The EPDS is a specifically designed measure of postnatal depression that has shown reliability and validity for the postpartum period.^14-16 It consists of a 10-item self-report scale, with each item scored 0-3. A score of 13 or above is indicative of postnatal depression. It is not contaminated by symptoms (e.g., fatigue, weight loss, broken sleep) which may be reported by healthy nursing mothers.

Tennant and Andrews life events scale:^17,18 A self-report scale comprising 10 relevant life events (e.g., death of a family member or close friend, moving house, marriage); subjects were asked whether each event had happened to her over the past 12 months. A modified version of this scale was used in our study.

Structured Clinical Interview for DSM-III-R (SCID):¹⁹ The SCID was administered to confirm postnatal depression "caseness". Postnatal depression was defined as meeting the criteria for major depression according to the Diagnostic and statistical manual of mental disorders, third edition, revised (DSM-III-R).²⁰  

Procedure

The women were assessed a further four times -- at six, 12, 18 and 24 weeks post partum. At each interval, the women were posted the EPDS, a self-report questionnaire (consisting of questions on the baby's condition and feeding patterns as well as the quality of the women's relationship) and a stamped self-addressed envelope for returning the forms.

Women who scored > 13 on the EPDS on two occasions (excluding their baseline EPDS score) were further interviewed using the SCID to determine postnatal depression "caseness". An equal number of women who scored < 13 on the EPDS were randomly selected and interviewed using the SCID.  

Statistical analysis

Results

Sample

Twenty-six women did not meet the inclusion criteria, 122 refused to participate in the study and 79 were unable to be contacted. There were no statistically significant differences in demographic and obstetric details between women who consented to participate and women who did not consent.

The 97 women who withdrew from the study or had insufficient data were more likely to be younger (t = 5.91; P < 0.01), unemployed (chi-squared = 33.37; P < 0.01), single or separated (chi-squared = 59.46; P < 0.01) and have fewer years of formal education (t = 3.47; P < 0.01) compared with women who had full data.

Forty-two women (9.9%) were categorised as having major depression, based upon scoring > 13 on the EPDS on two occasions and meeting DSM-III-R criteria for major depression. All of these women met "caseness" criteria for major depression on the SCID. None of the sample of women who screened negative (< 13) on the EPDS and were interviewed using the SCID met "caseness" criteria for major depression.  

Length of stay

We compared sociodemographic and risk factors for the early-discharge and standard-length-of-stay groups of women. The early-discharge group were more likely to be multiparous (71.2% v. 48.5%; OR, 2.63; 95% confidence interval [CI], 1.69-4.10), have fewer years of formal education (11.01 years v. 11.5 years; t = 3.09; P < 0.01), to bottle feed in the first week post partum (20.9% v. 12.1%; OR, 1.91; 95% CI, 1.06-3.46), and report a poor relationship with parents (52.9% v. 40.1%; OR, 1.68; 95% CI, 1.11-2.56). They were also more likely to have a history of depression or postnatal depression, but this was not statistically significant (9.1% v. 4.4%; OR, 2.18; 95% CI, 0.92-5.19). The two groups did not differ with respect to age, marital or socioeconomic status, number of life events in the past year, or global satisfaction with their partner. Women in the early discharge group did not have a more vulnerable personality style and did not differ in baseline EPDS scores (5.1 v. 5.9; t = 0.24).  

Postnatal assessment

Of the 153 women discharged early (within 72 hours), 22 (14.4%) developed postnatal depression compared with 20 of the 272 women (7.4%) who had standard length of stay (OR, 2.12; 95% CI, 1.07-4.21). Of the 42 women who developed postnatal depression, 22 (52.4%) were discharged early.

The possibility that the increased risk associated with early discharge could have arisen as a result of other, antecedent, risk factors for postnatal depression was examined using a hierarchical logistic regression,²² with postnatal depression as the dependent variable. Sociodemographic, historical, obstetric, and psychosocial factors (see below) were entered in the first step, baseline EPDS score in the second step and early discharge in the final step to see whether it would remain a risk factor after controlling for other risk factors.

• Sociodemographic factors: Age (5-yearly intervals), level of education (less or more than 10 years), social class (low or high socioeconomic status) and marital status (single, married or de facto relationship).

• Obstetric factors: Parity (multiparous or primiparous) and delivery type (spontaneous vaginal delivery, instrumental delivery or caesarean section).

• Psychosocial risk factors: Personality style (high or low vulnerability [extracted from the personality scale, with women scoring one standard deviation above the mean on the vulnerability component of the scale considered to be vulnerable]); quality of relationship with parents and in-laws (poor or good); satisfaction with relationship with partner (dissatisfied or satisfied); history of depression or postnatal depression; experience of none, one or two, or three or more life events over the previous 12 months; and whether they had had the desired-sex baby.

The model significantly improved (had better predictive power; chi-squared = 41.5; P < 0.0001) when baseline EPDS score was entered, and again when early discharge was entered. Early discharge increased the risk threefold (OR, 3.06; 95% CI, 1.22-7.69), after controlling for other risk factors. These results also support the more specific finding of early discharge, in which there was a 2.1-fold increased risk (95% CI, 1.07-4.21) of developing postnatal depression.  

Discussion

While there have been no prospective studies on the psychological impact of early discharge in heterogeneous samples, one retrospective study found that women who reported that their postnatal hospital stay was too short were significantly more likely to have postnatal depression than those who reported the right length of stay.²⁷

Our study shows that women discharged within three days of childbirth had an increased risk of developing postnatal depression. This increased risk is not the result of other well recognised risk factors for postnatal depression, such as experiencing life stresses, having a dysfunctional personality style, unsatisfactory interpersonal relationships²⁸ or a history of depression. When these risk factors were controlled in a logistic regression analysis, early discharge was still a significant risk for postnatal depression, with an odds ratio of 3.06. Therefore, early discharge exerted an independent effect on the development of postnatal depression and was not simply a proxy for other, pre-existing, risk factors.

We also found that one-third of the women who stayed in hospital for more than five days also experienced postnatal depression. However, they had all experienced complicated labours and some infants had been in neonatal intensive care for a prolonged period, which may have contributed to the higher rates of postnatal depression.

Women discharged within three days of giving birth may be at an increased risk of postnatal depression because they have had insufficient time to recover from and work through the experience of childbirth. They may still be tired from the physical demands of childbirth and have to return to the stresses of everyday life, which includes looking after a household, their new baby and, in many cases, other children. This additional stress so soon after childbirth may increase the risk of depression.

The "blues" are minor, transient depressive symptoms which generally arise on the third to fifth day post partum. Therefore, women on an early-discharge program leave hospital before the onset of the "blues". If they return to an environment where there is insufficient support, experiencing the "blues" may lead to depressive symptoms being perpetuated and contribute to the development of postnatal depression.

Finally, women discharged early go home without having properly established breastfeeding, and therefore without the supervision and round-the-clock support of midwives to help them with the inevitable difficulties (e.g., breast engorgement, change in milk flow, unable to latch the baby correctly, leading to cracked, sore nipples) that arise after the milk "comes in" (generally on the third day). These difficulties can lead to an irritable baby and a tired, depressed mother.

The association we found between early discharge and postnatal depression merely suggests causality. A prospective controlled study with women randomly assigned to early- or standard-discharge programs (controlling for parity, social support and past history) is needed to identify any causal link between early discharge and postnatal depression.

The association between early discharge and postnatal depression has major public health implications. While health services are having to cut costs, early discharge may result in short-term cost savings. However, the consequences of postnatal depression could lead to escalating health care costs in the long term.

Women entering an early-discharge program need a careful assessment, particularly those at risk for postnatal depression (e.g., poor family support or a history of depression). The possibility of postnatal depression should be kept in mind for all women who have been discharged early when they return for their postnatal check-ups. The EPDS could be used as a routine screen for such women. Finally, women with a history of postnatal depression should have counselling if they are considering early discharge and be advised that a longer hospital stay may reduce their risk of recurrent depression.  

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(Received 17 Feb, accepted 5 June 1997)