Association between ambulance prehospital time and maternal and perinatal outcomes in Sierra Leone: a countrywide study

INTRODUCTION: Sierra Leone, one of the countries with the highest maternal and perinatal mortality in the world, launched its first National Emergency Medical Service (NEMS) in 2018. We carried out a countrywide assessment to analyse NEMS operational times for obstetric emergencies in respect the access to timely essential surgery within 2 hours. Moreover, we evaluated the relationship between operational times and maternal and perinatal mortality. METHODS: We collected prehospital data of 6387 obstetric emergencies referrals from primary health units to hospital facilities between June 2019 and May 2020 and we estimated the proportion of referrals with a prehospital time (PT) within 2 hours. The association between PT and mortality was investigated using Poisson regression models for binary data. RESULTS: At the national level, the proportion of emergency obstetric referrals with a PT within 2 hours was 58.5% (95% CI 56.9% to 60.1%) during the rainy season and 61.4% (95% CI 59.5% to 63.2%) during the dry season. Results were substantially different between districts, with the capital city of Freetown reporting more than 90% of referrals within the benchmark and some rural districts less than 40%. Risk of maternal death at 60, 120 and 180 min of PT was 1.8%, 3.8% and 4.3%, respectively. Corresponding figures for perinatal mortality were 16%, 18% and 25%. CONCLUSION: NEMS operational times for obstetric emergencies in Sierra Leone vary greatly and referral transports in rural areas struggle to reach essential surgery within 2 hours. Maternal and perinatal risk of death increased concurrently with operational times, even beyond the 2-hour target, therefore, any reduction of the time to reach the hospital, may translate into improved patient outcomes.