A retrospective observational case-controlled cohort study, including adults with laboratory-confirmed COVID-19 in a single center in Turkey, was performed between March 2020 and September 2020 at Eskişehir City Hospital. All patients who were treated and followed by the researchers at our hospital were included in the study. The patient's medical records were gathered in the hospital's electronic database. Patients groups of the study were determined according to the recommendations of the guidelines published by the Turkish Ministry of Health's Scientific Committee updated on different dates. All patients were evaluated in terms of their epidemiological and demographic characteristics, laboratory and radio-diagnostic tests, treatment features, and outcomes. Medical ethics committee approval was obtained prior to the study. Routine blood tests were recorded of the patients at first hospitalization; Complete Blood Count (CBC), C-reactive protein (CRP), Ferritin, D-Dimer, liver and kidney function tests, SARS-CoV-2 nucleic acid, and other laboratory results were compared to subsequent simultaneous controls. The primary endpoint was reaching PCR negativity. The secondary endpoints were the rate of admission to an ICU and the rate of death. Clinical classification of the mild, moderate, severe, and critical patients was performed according to the WHO guideline .
Chest CT scans were conducted on day 1 and the 14th day of hospitalization. In the study, patients with confirmed COVID-19 pneumonia, serial chest CT scans were recorded and reviewed by three physicians. We use COVID-19 Reporting and Data System (CO-RADS) for standardized assessment of pulmonary involvement and classification of COVID-19 patients' findings in our study. The CO-RADS classification evaluates the suspected pulmonary involvement of COVID-19 on a scale from 0 (not interpretable) to 5 (proven) . This classification is specifically designed for use in patients with moderate to severe symptoms of COVID-19.
In terms of eligibility criteria, we evaluated all patients admitted to three groups. Inclusion criteria were positive SARS-Cov-2 virus reverse transcription PCR (RT-PCR) test, age > 18 years old, no difficulty in swallowing the pills, and hospitalized in COVID-19 clinics and ICU. The exclusion criteria included the following: patients who do not have PCR testing or inadequate diagnosis, patients with mental disorders, previous history of allergic reactions, patients with elevated ALT/AST (> 6 × upper limits of normal range) or with chronic liver disease and cirrhosis, patients with a history of all lung diseases other than COPD, pregnant or lactating women; women of childbearing age with a positive pregnancy test and breastfeeding.
We informed our staff at our medical center for FPV, which is recommended by the COVID-19 treatment algorithms in guidelines published by the Turkish Ministry of Health's Scientific Committee for moderate to severe disease in April 2020 and asymptomatic to the severe disease for all definite cases in October 2020. Patients were divided into three groups of treated with FPV / (HQ) combination early (Group1) versus late (Group 2) and HQ only (Group 3). The treatment regime was; FPV 1600 mg twice the first day, followed by 600 mg twice daily, for the following days for five days at standard treatment and HQ 400 mg for five days. In Group 2, we treated HQ initially; if the respiratory or clinic condition had not improved sufficiently, FPV was added on or after day 3. In both groups, patients took supportive treatments such as oxygen inhalation, intravenous and oral hydration, antibiotics, antipyretics, and analgesics when needed.
The diagnosis, monitoring, and treatment for COVID-19 were based on the guidelines published by the Turkish Ministry of Health's Scientific Committee on COVID-19 . Sampling was taken as a throat swab at seven days intervals in our study until a negative result was seen (1, 5, 7, 14, 21, and 28). All samples were tested in our biosafety level-2 (BSL-2) laboratory facility with full personal protective equipment. Viral analyses and real-time (Q) PCR experiments were applied to the sample of the patient. The RNA was isolated using vNAT solution (Bioeksen, Istanbul, Turkey). For all reactions, Rotor-Gene Q (Qiagen) and LightCycler 480 (Roche) instrument, and Biospeedy SARSCoV-2 RT-qPCR kit (Bioeksen) were used. The kit is performed in one step with targeting the RdRp (RNA-dependent RNA polymerase) gene fragment reverse transcription (RT) and rt PCR (QPCR) (RT-QPCR). The data was analyzed using Rotor-Gene Q and LightCycler 480 Software. Bio-Speedy kit used (which Bioeks, Istanbul, Turkey), Coronavirus Disease 2019 (Covidien-19) that leads to disease pandemics of SARS-CoV-2 (2019-NCover) is used for the detection of the virus. The kit is applied to nucleic acid isolates from nasopharyngeal aspirate/lavage, bronchoalveolar lavage, nasopharyngeal swab, oropharyngeal swab, and sputum samples. The shape of the growth curves obtained from the FAM / HEX channels is examined. Non-sigmoidal curves are recorded as negative. The threshold cycle number (Cq) is calculated. The sensitivity and specificity of the Biospeedy kit is 98.7–100%, respectively.
Evaluation of response to treatment
Laboratory parameters were evaluated on the day of hospitalization, and routine examinations were performed on the 7th day. Values were compared numerically. While evaluating the effectiveness of the treatment in the patients, it was interpreted by comparing the computed tomography (CT) scans with the clinical conditions after the 14th day of hospitalization. The PCR test was checked on the 7th day of the first test to interpret the drug's effectiveness, and it must be negative.
The study was approved by the Turkish Ministry of Health and the Ethics Committee of the Faculty of Medicine at Eskişehir Osmangazi University (approval number 2020/259) and was carried out in accordance with the Declaration of Helsinki principles and all applicable regulations.
Descriptive data are presented as either means or median for continuous variables, frequencies and percentages are reported for categorical variables. We reported continuous data as mean ± standard deviation, or median, and minimum–maximum according to their distribution. Pearson X2 test is used to assessing the associations in categorical variables. The pre and post values of the parameters were compared using the paired sample t test and two-way ANOVA. Tukey's test and Games Howell tests were preferred as posthoc tests. The time to clinical improvement was portrayed by Kaplan–Meier plot and compared with a log-rank test. Hazard ratios with 95% confidence intervals were calculated by means of the Cox proportional-hazards model. A p-value of < 0.005 is considered as statistical significance. The statistical analysis of the study was performed with SPSS software (Statistical Package for the Social Sciences, version 22.0, SPSS Inc, Chicago, IL).