Is the JRS atypical pneumonia prediction score useful in detecting COVID-19 pneumonia under nursing or healthcare settings?

Background: SARS-CoV-2 causes frequent outbreaks in elderly care facilities that meet the criteria for nursing and healthcare -associated pneumonia (NHCAP). We evaluated whether the Japanese Respiratory Society (JRS) atypical pneumonia prediction score could be adapted to the diagnosis of nursing and healthcare acquired COVID-19 (NHA-COVID-19) with pneumonia. Methods: We analyzed 516 pneumonia patients with NHA-COVID-19 and compared them with 1505 pneumonia patients with community -associated COVID-19 (CA-COVID-19). NHA-COVID-19 patients were divided into six groups; 80 cases had the ancestral strain, 76 cases had the Alfa variant, 30 cases had the Delta variant, 120 cases had the Omicron subvariant BA.1, 53 cases had the Omicron subvariant BA.2, and 157 cases had the Omicron subvariant BA.5. Results: The sensitivities of the diagnosis of atypical pneumonia in patients with NHA-COVID-19 based on four or more predictors were 22.8 % in the ancestral strain group, 32.0 % in the Alfa variant group, 34.5 % in the Delta variant group, 23.1 % in the BA.1 subvariant group, 32.7 % in the BA.2 subvariant group, and 30.4 % in the BA.5 subvariant group. The diagnostic sensitivity for the presumptive diagnosis of atypical pneumonia was significantly lower for NHA-COVID-19 than for CA-COVID-19 (28.2 % vs 64.1 %, p < 0.0001). Conclusions: Our present study demonstrated that the JRS atypical pneumonia prediction score is not a useful tool in elderly patients even if there is a lot of atypical pneumonia in the NHCAP group. The caution is necessary that JRS atypical pneumonia prediction score was not fully applied to prediction for NHA-COVID-19 pneumonia.