Background and Objective: Considering hypertension as the most prevalent comorbidity among patients diagnosed with COVID-19, this study intended to investigate clinical characteristics and in-hospital mortality risk factors among COVID-19 patients with hypertension history.
Methods: This descriptive-analytical study was conducted on 527 hypertensive patients (277 male and 250 female) a mean age of 64.73±13.13 years infected with COVID-19 and hospitalized at Sayyad Shirazi Hospital, Gorgan Iran from February to September 2020. The patients’ data were extracted from the hospital information system and completed by patients’ medical records and telephone calls. The association between the risk factors and in-hospital mortality was identified by employing the logistic regression analysis in three various models, including model 1 (demographic data and patients’ history), model 2 (model 1 plus vital signs and pulse oximetry measurement at hospital admission) model 3 (model 2 plus laboratory findings at hospital admission). Each model individually described the odds ratios (ORs) with 95% confidence intervals (95% CIs) for every risk factor. Furthermore, a corrected area under the receiver-operating characteristics curve (AUC) was estimated to evaluate the model’s discriminatory power.
Results: Among 527 hospitalized patients, 88 patients (16.6 %) died during 6.48 days of hospitalization, of which 47 patients were men. In model 1, opium consumption (CI95%=1.16-3.85, OR=2.11) and cognitive impairment at admission (CI95%=0.98-5.40, OR=2.30) were significantly associated with higher mortality (AUC=0.65). In model 2, after adding vital signs and oxygen saturation, cognitive impairment association lost its association, and only opium consumption (CI95%=1.09-3.19, OR=1.87) and oxygen saturation (CI95%=0.90-0.95, OR=0.93) were associated with in-hospital mortality. (AUC=0.73). In model 3, after incorporating laboratory findings, with an AUC of 0.79 (CI95%=0.70-0.90), each percent higher oxygen saturation at admission was associated with a 7% decrease in in-hospital mortality (CI95%=0.88-1.00, OR=0.93). Although opium consumption and higher creatinine level lead to higher mortality, the associations were not significant.
Conclusion: Regarding the association of oxygen saturation at admission with in-hospital mortality among hypertensive patients diagnosed with COVID-19, the pulse oximetry measurement data upon admission would be crucial in evaluating these patients.