Spatial variability of Middle East respiratory syndrome coronavirus survival rates and mortality hazard in Saudi Arabia, 2012–2019

Abstract

About 83% of laboratory-confirmed Middle East respiratory syndrome coronavirus (MERS-CoV) cases have emerged from Saudi Arabia, which has the highest overall mortality rate worldwide. This retrospective study assesses the impact of spatial/patient characteristics for 14-and 45-day MERS-CoV mortality using 2012–2019 data reported across Saudi regions and provinces. The Kaplan–Meier estimator was employed to estimate MERS-CoV survival rates, Cox proportional-hazards (CPH) models were applied to estimate hazard ratios (HRs) for 14-and 45-day mortality predictors, and univariate local spatial autocorrelation and multivariate spatial clustering analyses were used to assess the spatial correlation. The 14-day, 45-day and overall mortality rates (with estimated survival rates) were 25.52% (70.20%), 32.35% (57.70%) and 37.30% (56.50%), respectively, with no significant rate variations between Saudi regions and provinces. Nationally, the CPH multivariate model identified that being elderly (age ≥ 61), being a non-healthcare worker (non-HCW), and having an underlying comorbidity were significantly related to 14-day mortality (HR = 2.10, 10.12 and 4.11, respectively; p < 0.0001). The 45-day mortality model identified similar risk factors but with an additional factor: patients aged 41–60 (HR = 1.44; p < 0.0001). Risk factors similar to those in the national model were observed in the Central, East and West regions and Riyadh, Makkah, Eastern, Madinah and Qassim provinces but with varying HRs. Spatial clusters of MERS-CoV mortality in the provinces were identified based on the risk factors (r2 = 0.85–0.97): Riyadh (Cluster 1), Eastern, Makkah and Qassim (Cluster 2), and other provinces in the north and south of the country (Cluster 3). The estimated HRs for the 14-and 45-day mortality varied spatially by province. For 45-day mortality, the highest HRs were found in Makkah (age ≥ 61 and non-HCWs), Riyadh (comorbidity) and Madinah (age 41–60). Coming from Makkah (HR = 1.30 and 1.27) or Qassim province (HR = 1.77 and 1.70) was independently related to higher 14-and 45-day mortality, respectively. MERS-CoV patient survival could be improved by implementing appropriate interventions for the elderly, those with comorbidities and non-HCW patients.