Date Published: May 16, 2019
Publisher: Public Library of Science
Author(s): Tanneke Herklots, Lieke van Acht, Rashid Saleh Khamis, Tarek Meguid, Arie Franx, Benoit Jacod, Cheryl A. Moyer.
To evaluate the validity of WHO’s near-miss approach in a low-resource, high maternal mortality setting.
Prospective cohort study.
Mnazi Mmoja Hospital, the main referral hospital of Zanzibar, Tanzania, from 1 April 2017 until 31 December 2018.
All women, pregnant or until 42 days after the end of pregnancy, admitted at Mnazi Mmoja Hospital, the tertiary referral hospital in Zanzibar.
Cases of maternal morbidity and mortality were evaluated according to WHO’s near-miss approach. The approach’s performance was determined by calculating its accuracy through sensitivity, specificity and positive and negative likelihood ratios. The approach’s validity was assessed with Pearson’s correlation coefficient between the number of organ dysfunction markers and risk of mortality.
Correlation between number of organ dysfunction markers and risk of mortality, sensitivity and specificity.
26,842 women were included. There were 335 with a severe maternal outcome: 256 maternal near-miss cases and 79 maternal deaths. No signs of organ dysfunction were documented in only 4 of the 79 cases of maternal death. The number of organ dysfunction markers was highly correlated to the risk of mortality with Pearson’s correlation coefficient of 0.89.
WHO’s near-miss approach adequately identifies women at high risk of maternal mortality in Zanzibar’s referral hospital. There is a strong correlation between the number of markers of organ dysfunction and mortality risk.
With globally declining maternal mortality rates (MMR), assessment of severe maternal morbidity is increasingly important in addition to maternal death reviews to evaluate the quality of maternal health care. This has led to reviews and audits of maternal morbidity in not only middle- and high-income countries, where mortality rates are low, but also at facility-level in low-income settings where, despite high morbidity and mortality rates, maternal deaths are relatively rare events. Severe maternal morbidity cases should, however, be selected in such a way as to reflect the same processes as maternal mortality cases. That assumption is not straightforward because causes of severe maternal morbidity are not necessarily those leading to maternal death . In order to draw valid conclusions from an audit process combining maternal morbidity and mortality, one should therefore select cases in which the woman nearly died, designated by the term maternal “near-misses” . The definition of near-misses however intuitive is not unequivocal in practice [3–5]. This led the World Health Organization (WHO) to propose a definition using markers of organ failure, based on scoring systems used in intensive care medicine: the WHO near-miss approach . In practice, this approach uses a two-step system in which women potentially at risk of dying are identified first through disease- and management-based criteria. This is followed by identification of women within this group that are really at risk of dying based on the occurrence of markers of organ failure [2,4]. The final clinical outcome for women in these group is either near-miss—those who survived—or death.
During the 21-months study period, 26,842 women admitted at MMH–pregnant or within 42 days after end of pregnancy–were included. There were 22,054 deliveries and 22,011 recorded live births (including all live births in cases of multiple pregnancies), 335 (1.3%) women had a severe maternal outcome (SMO), with 256 (1.0%) maternal near-misses and 79 (0.3%) maternal deaths. Maternal outcomes are further detailed in Table 2. The in-hospital maternal mortality ratio (MMR) was 359 per 100,000 live births. A high mortality index (MI) of 0.24 was found, indicating that of all women undergoing very severe morbidity, close to one quarter had died.
WHO’s near-miss approach adequately identifies women at high risk of maternal mortality in Zanzibar’s referral hospital. There is a strong correlation between the number of markers of organ dysfunction and mortality risk while only very few mortality cases do not fulfil any WHO criteria. The mortality index is an appropriate measure of quality of maternal health care complementing mortality rates.