Ilari Kuitunen

BACKGROUND: Social distancing measures are used to reduce the spreading of infection. Our aim was to assess the immediate effects of national lockdown orders due to coronavirus disease 2019 (COVID-19) on pediatric emergency room (ER) visits and respiratory tract infections in hospitals and nationwide in Finland. METHODS: This register-based study used hospital patient information systems and the Finnish national infectious disease register. The participants were all patients visiting pediatric ER in 2 Finnish hospitals (Kuopio University Hospital, Mikkeli Central Hospital) covering 1/5th of the Finnish children population, 4 weeks before and 4 weeks after the start of the nationwide lockdown on March 16, 2020. Nationwide weekly numbers of influenza (A + B) and respiratory syncytial virus (RSV) in children were assessed from the infectious disease register from 2015 to 2020. RESULTS: A major decrease in the rate of daily median pediatric ER visits was detected in both hospitals in the study during the nationwide lockdown compared with the study period before the lockdown (Mikkeli, 19 vs. 7, P < 0.001; Kuopio, 9 vs. 2,5, P < 0.001). The influenza season was shorter (8 weeks from peak to no cases), and the weekly rate of new cases decreased faster compared with the previous 4 influenza seasons (previously 15-20 weeks from peak to no cases). A similar decrease was also seen in RSV cases. No pediatric cases of COVID-19 were found in participating hospitals during the study period. CONCLUSION: These results strongly suggest that social distancing and other lockdown strategies are effective to slow down the spreading of common respiratory viral diseases and decreasing the need for hospitalization among children.

BACKGROUND: Survival analysis and effect of covariates on survival time is a central research interest. Cox proportional hazards regression remains as a gold standard in the survival analysis. The Cox model relies on the assumption of proportional hazards (PH) across different covariates. PH assumptions should be assessed and handled if violated. Our aim was to investigate the reporting of the Cox regression model details and testing of the PH assumption in survival analysis in total joint arthroplasty (TJA) studies. METHODS: We conducted a review in the PubMed database on 28th August 2019. A total of 1154 studies were identified. The abstracts of these studies were screened for words "cox and "hazard*" and if either was found the abstract was read. The abstract had to fulfill the following criteria to be included in the full-text phase: topic was knee or hip TJA surgery; survival analysis was used, and hazard ratio reported. If all the presented criteria were met, the full-text version of the article was then read. The full-text was included if Cox method was used to analyze TJA survival. After accessing the full-texts 318 articles were included in final analysis. RESULTS: The PH assumption was mentioned in 114 of the included studies (36%). KM analysis was used in 281 (88%) studies and the KM curves were presented graphically in 243 of these (87%). In 110 (45%) studies, the KM survival curves crossed in at least one of the presented figures. The most common way to test the PH assumption was to inspect the log-minus-log plots (n = 59). The time-axis division method was the most used corrected model (n = 30) in cox analysis. Of the 318 included studies only 63 (20%) met the following criteria: PH assumption mentioned, PH assumption tested, testing method of the PH assumption named, the result of the testing mentioned, and the Cox regression model corrected, if required. CONCLUSIONS: Reporting and testing of the PH assumption and dealing with non-proportionality in hip and knee TJA studies was limited. More awareness and education regarding the assumptions behind the used statistical models among researchers, reviewers and editors are needed to improve the quality of TJA research. This could be achieved by better collaboration with methodologists and statisticians and introducing more specific reporting guidelines for TJA studies. Neglecting obvious non-proportionality undermines the overall research efforts since causes of non-proportionality, such as possible underlying pathomechanisms, are not considered and discussed.

BACKGROUND: COVID-19 outbreak lead to nationwide lockdown in Finland on the March 16th, 2020. Previous data regarding to the patient load in the emergency departments during pandemics is scarce. Our aim is to describe the effect of national lockdown and social distancing on the number and reasons for emergency department (ED) visits and inpatient admissions in three large volume hospitals prior to and after the outbreak of the COVID-19 epidemic in Finland. METHODS: Data for this register-based retrospective cohort study were collected from three large ED's in Finland, covering 1/6 of the Finnish population. All patients visiting ED's six weeks before and six weeks after the lockdown were included. Pediatric and gynecological patients were excluded. Numbers and reasons for ED visits and inpatient admissions were collected. Corresponding time period in 2019 was used as reference. RESULTS: A total of 40,653 ED visits and 12,226 inpatient admissions were analyzed. The total number of ED visits decreased 16% after the lockdown, whereas the number of inpatient admissions decreased 15% (p < 0.001). This change in inpatient admissions was similar in all participating hospitals. Visits due to back or limb pain decreased 31% and infectious diseases 28%. The visit rate and inpatient admissions due to acute myocardial infarction and strokes remained stable throughout the study period. Interestingly, the rate of inpatient admissions due to psychiatric diagnoses remained unchanged, although the ED visit rate decreased by 19%. The number of ED visits (n = 282) and inpatient admissions (n = 55) due to COVID-19 remained low in the participating hospitals. CONCLUSIONS: Changes in ED visits and inpatient admissions prior to and during the early phase of the COVID-19 outbreak were unpredictable, and our results may help hospitals and especially ED's focus their resources better. Surprisingly, there was a major decrease in the rate of ED visits due to back or limb pain and not so surprisingly in infectious diseases. Rates of acute myocardial infarctions and cerebral strokes remained stable. In summary, stabile resources for the treatment of patients with severe diseases will be needed in hospitals and ED's.

BACKGROUND: A concern has been that health care reorganizations during the first COVID-19 wave have led to delays in elective surgeries, resulting in increased complications and even mortality. This multicenter study examined the changes in waiting times of elective surgeries during the COVID-19 pandemic in Finland. METHODS: Data on elective surgery were gathered from three Finnish public hospitals for years 2017-2020. Surgery incidence and waiting times were examined and the year 2020 was compared to the reference years 2017-2019. The mean annual, monthly, and weekly waiting times were calculated with 95% confidence intervals (CI). The most common diagnosis groups were examined separately. FINDINGS: A total of 88 693 surgeries were included during the study period. The mean waiting time in 2020 was 92.6 (CI 91.5-93.8) days, whereas the mean waiting time in the reference years was 85.8 (CI 85.1-86.5) days, resulting in an average 8% increase in waiting times in 2020. Elective procedure incidence decreased rapidly in the onset of the first COVID-19 wave in March 2020 but recovered in May and June, after which the surgery incidence was 22% higher than in the reference years and remained at this level until the end of the year. In May 2020 and thereafter until November, waiting times were longer with monthly increases varying between 7% and 34%. In gastrointestinal and genitourinary diseases and neoplasms, waiting times were longer in 2020. In cardiovascular and musculoskeletal diseases, waiting times were shorter in 2020. CONCLUSION: The health care reorganizations due to the pandemic have increased elective surgery waiting times by as much as one-third, even though the elective surgery rate increased by one-fifth after the lockdown.

BACKGROUND: Nationwide restrictions started in Finland in March to prevent the spread of COVID-19, leading to school and day care closures. The aim of this study is to describe the effect of closures and re-openings on the respiratory pathogen epidemiology. METHODS: Laboratory-confirmed cases of SARS-CoV-2; respiratory syncytial virus (RSV); influenza (A & B); parainfluenza-, adeno-, and rhinoviruses; Mycoplasma pneumoniae; and Streptococcus pneumoniae in children were collected from the National Infectious Disease Register over the period of 2017-2020. Weekly incidences (weeks 1 to 35) with 95% confidence intervals (CIs) were calculated per 100 000 children in 2020 and compared by incidence rate ratios (IRRs) to corresponding periods in 2017-2019. FINDINGS: The lockdown had immediate impact on the incidences of respiratory pathogens except SARS-CoV-2. Week after the lockdown began IRR was 0•3 (CI 0•3-0•4) and next week the IRR was 0•1 (0•1-0•2). The incidence of SARS-CoV-2 started to decline eight weeks after the lockdown began. The highest recorded weekly incidence of SARS-CoV-2 was 7•2/100 000 children. The effect of the lockdown lasted until late summer. Rhinovirus and SARS-CoV-2 began to increase before the schools or day cares opened in August. The re-opening of schools seemed to have no impact on the incidence of any pathogen. INTERPRETATION: Our results suggest that general social distancing, including school and day care closures, played a crucial role in reducing infections, and the effect lasted for several weeks. The re-opening of schools and day care centres seems to have had no immediate impact on the incidences of any respiratory pathogens. FUNDING: This study had no funding source.