Comparison of clinical characteristics and outcome measures of PCR-positive and PCR-negative patients diagnosed as COVID-19: Analyses focusing on the older adults.

While the definitive diagnosis of COVID-19 relies on PCR confirmation of the virus, the sensitivity of this technique is limited. The clinicians had to go on with the clinical diagnosis of COVID-19 in selected cases. We aimed to compare PCR-positive and PCR-negative patients diagnosed as COVID-19 with a specific focus on older adults. We studied 601 hospitalized adults. The demographics, co-morbidities, triage clinical, laboratory characteristics, and outcomes were noted. Differences between the PCR (+) and (-) cases were analyzed. An additional specific analysis focusing on older adults (≥65 years) (n = 184) was performed. The PCR confirmation was present in 359 (59.7 %). There was not any difference in terms of age, sex, travel/contact history, hospitalization duration, ICU need, the time between first symptom/hospitalization to ICU need, ICU days, or survival between PCR-positive and negative cases in the total study group and older adults subgroup. The only symptoms that were different in prevalence between PCR-confirmed and unconfirmed cases were fever (73.3 % vs. 64 %, p = 0.02) and fatigue/myalgia (91.1 % vs. 79.3 %, p = 0.001). Bilateral diffuse pneumonia was also more prevalent in PCR-confirmed cases (20 % vs. 13.3 %, p = 0.03). In older adults, the PCR (-) cases had more prevalent dyspnea (72.2 % vs. 51.4 %, p = 0.004), less prevalent fatigue/myalgia (70.9 % vs. 88.6 %, p = 0.002). The PCR (+) and (-) cases displayed very similar disease phenotypes, courses, and outcomes with few differences between each other. The presence of some worse laboratory findings may indicate a worse immune protective response in PCR (-) cases.

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Declaration of competing interest All authors declare no competing financial disclosure. All authors declare no competing conflict of interest. Special thanks to European Geriatric Medicine Society for letting us present earlier version of this manuscript as conference abstract in “Abstracts of the 16th International E-Congress of the European Geriatric Medicine Society”.