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.