Comparing different diagnostic approaches to severe maternal morbidity and near-miss: a pilot study in a Brazilian tertiary hospital

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Abstract

Objective

Despite recent guidelines proposed by the World Health Organization (WHO), the operational definition of maternal near-miss (MNM) is still heterogeneous. This study aimed at evaluating the pros and cons of three instruments in characterizing MNM cases. The performance of two of the three instruments was also investigated vis-à-vis the WHO criteria.

Study design

A retrospective chart review study was carried out in a tertiary maternity hospital in Rio de Janeiro, Brazil. The medical records of 1163 obstetric hospital admissions from January to December 2008 were reviewed. Cases were first classified as ‘positive’ or otherwise according to the WHO, Waterstone and literature-based criteria. A descriptive analysis was then carried out focusing on divergent classifications. Finally, diagnostic properties of the Waterstone and the literature-based criteria were calculated taking the WHO criteria as reference standard.

Results

There were eight maternal deaths, 157 cases classified as ‘positive’ by at least one of the three approaches and 998 cases without severe morbidities. Twenty-seven cases of MNM were detected according to the WHO criteria, whereas the Waterstone and the literature-based criteria identified 123 and 153 cases, respectively. Among the 130 cases identified as ‘negative’ by the WHO criteria and ‘positive’ by the Waterstone or literature-based criteria, 119 presented hypertensive disorders (91.5%). Additionally, four cases were identified exclusively by the WHO criteria because of acute thrombocytopenia (platelets < 50,000). Estimates of sensitivity, specificity, accuracy and negative predictive values were all above 75% for the Waterstone and literature-based approaches, but both criteria presented positive predictive values (PPV) below 60% even with high magnitudes of MNM.

Conclusion

These results underline that different approaches entail heterogeneous estimates of MNM. The Waterstone and the literature-based criteria are not suitable for a definitive diagnosis of MNM in view of their low PPV, but they seem adequate as a first approach in investigating MNM. While negative results by both alternative criteria virtually rule out MNM, a positive result would require a reassessment using the WHO criteria to confirm the diagnosis of maternal near-miss.

Introduction

Recent statistics provided by the World Health Organization (WHO) and the United Nations [1], [2] indicated major advances in the provision of interventions to reduce maternal deaths, including access to family planning and skilled health care during pregnancy and childbirth. A reduction in maternal mortality of approximately one third has also been observed between 1990 and 2008 [1], [2], suggesting that such interventions were somehow effective. Nevertheless, this decrease in maternal mortality is not sufficient for the fulfillment of the fifth Millennium Development Goal, which proposed a reduction of maternal mortality by three quarters between 1990 and 2015 [2]. Therefore, women's deaths during pregnancy, childbirth or the postpartum period remain an incumbent public health problem, especially in low and middle income countries.

Given this epidemiological context tarnished by a progressive yet insufficient fall in the rates of maternal deaths, several authors have advocated that the follow-up of cases in which women presented serious complications and almost died during pregnancy or childbirth would be an important strategy to assess the quality of the obstetric care [3], [4], [5], [6], [7]. Cases of maternal near-miss (MNM) share several similarities with cases of maternal death and would provide valuable information about possible obstacles to address when a woman presents with acute complications during pregnancy or the puerperium [5]. Experience stemming from a detailed study of MNM cases would serve as a foundation for effective training programs for health professionals in obstetric emergencies and, consequently, allow prevention of not only these cases but also maternal deaths per se [8]. Likewise, the incidence of MNM is valuable in assessing the impact of social or medical strategies implemented to improve maternal health. In addition, auditing MNM events may allow gathering of evidence from the woman's own account, enabling a better understanding of the conditions that might have contributed to the occurrence of serious obstetric and perinatal complications [4], [9], [10].

An important limitation, however, to the widespread adoption of the near-miss concept in maternal health has been the lack of standardized theoretical and operational definitions [11], [12]. As noted by Say et al. [12], the wide variation in criteria for identifying MNM cases makes it impossible to pool data or obtain consistent worldwide summary estimates. In 2009, a WHO expert group proposed a standardized approach (Table 1) to assess MNM, arguing that uniform diagnostic criteria are crucial for the effective integration of the ‘near-miss’ concept into obstetric care and related applied research [5]. The expert group pointed out to the advantages of using this WHO standard tool: for example, standardized indicators would enable comparisons across settings and time periods, regardless of the structural characteristics of health units. Moreover, its use would enable identification of cases in which maternal death was effectively imminent and, in turn, avoid overestimating the incidence of MNM.

Although several studies have adopted the WHO criteria [13], [14], [15], [16] since its proposal, others still adhered to previous definitions [17], [18], [19], ultimately leading to a persistent difficulty in comparing estimates. This study thus aims to contribute to a better understanding of how the use of different conceptual and operational definitions affects the interpretation of studies on MNM. Besides the ‘WHO criteria’, two other approaches were evaluated. The ‘Waterstone criteria’ (Table 2) focus on major obstetrical syndromes and include solely clinical items, making it unrestrictedly useful in both low- and high-resource settings [20]. The second approach is based on comprehensive literature review (Table 2) and encompasses events/items commonly used in the scientific literature on MNM [21]. These three diagnostic tools were evaluated with respect to the (dis)agreements in typifying severe maternal morbidities or MNM cases, as well as with regard to the component items mostly accounting for the potential disparities. Taking the WHO criteria as the reference, the usefulness as a diagnostic test of both the Waterstone and literature-based approaches was also investigated.

Section snippets

Material and methods

This is a retrospective chart review study carried out at the Pedro Ernesto University Hospital, a tertiary referral maternity of the Rio de Janeiro State University in Brazil. Data collection took place in 2010 but referred to hospital admissions during pregnancy, birth or postpartum occurring between 1 January and 31 December 2008. Out of 1170 hospital admissions, 1163 medical records were identified and reviewed by two trained obstetricians (M.N.P. and W.M.S.). The study was approved by the

Results

Of the 1163 hospital admissions whose records were available for review, eight were effective maternal deaths, 157 cases were classified as ‘positive’ by at least one of the three diagnostic tools and 998 cases showed no severe morbidities (Fig. 1). The WHO criteria detected only 27 cases of MNM, whereas 126 and 153 cases were identified as ‘positive’ according the Waterstone and the literature-based criteria, respectively. As there were 812 live births in the hospital in the reference period

Comments

As pointed out in several studies [11], [24], [25], using different diagnostic criteria may lead to an important heterogeneity in MNM estimates. For instance, current findings show that the Waterstone [20] and the literature-based [21] approaches tend to detect 4–6 times more cases than the WHO criteria [5]. This inconsistency clearly reiterates that comparison of studies employing different approaches should be avoided.

In effect, this distinction has been mentioned in a recent official WHO

Authorship

All authors have fulfilled condition required for authorship.

Conflict of interests

The authors have no conflicts of interest to declare.

Acknowledgments

The authors would also like to thank the staff of Pedro Ernesto University Hospital, who are willing to help data collection and made this research possible. The author MER was partially supported by the Brazilian National Research Council (CNPQ), processes no. 306909/2006-5 and 301221/2009-0.

References (28)

  • D. Siassakos et al.

    The active components of effective training in obstetric emergencies

    BJOG

    (2009)
  • T. Baskett et al.

    Severe obstetric maternal morbidity: a 15-year population-based study

    Journal of Obstetrics and Gynaecology

    (2005)
  • S.W. Wen et al.

    Severe maternal morbidity in Canada, 1991–2001

    Canadian Medical Association Journal

    (2005)
  • J.P. Souza et al.

    Systematic review of near miss maternal morbidity

    Cadernos de Saude Publica

    (2006)
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