Risk ratio (RR) and hazard ratio (HR) are two common effect measures in prospective studies. When describing the magnitude of clinical effects in the original study and meta-analysis, they cannot be used interchangeably. Selecting an appropriate measures and interpreting them correctly is critical in clinical research. In this study, we summarized similarities and differences between risk and hazard, compared differences between RR and HR in estimation methods and clinical interpretation. The magnitude of RR and HR estimated from the same studies were compared, and two feasible formulas converting between RR and HR were presented for meta-analysis.
ObjectiveTo analyze the disease burden of prostate, bladder and kidney cancers attributable to smoking in China from 1990 to 2019. MethodsBased on the global burden of disease study 2019, the current situation of the disease burden of prostate, bladder and kidney cancers attributable to smoking was analyzed by using the population attributable fraction (PAF), deaths and disability-adjusted life years (DALYs). Furthermore, the annual percent change (APC) and the average annual percent change (AAPC) were calculated by joinpoint regression analysis to describe the long-term trends of the smoking-attributable burden of these three cancers from 1990 to 2019. ResultsThere were an estimated 18 800 cases of deaths and 393 106 person-years of DALYs for bladder cancer caused by smoking in 2019. The age-standardized mortality and DALY rate decreased by 0.41% and 0.39% per year from 1990 to 2019, respectively. For prostate cancer, smoking was estimated to have caused 5 016 cases of deaths and 98 276 person-years of DALYs in 2019. The age-standardized mortality and DALY rate decreased by 0.28% and 0.25% per year from 1990 to 2019, respectively. For kidney cancer, the deaths and DALYs attributable to smoking were 4 935 cases and 120 620 person-years, respectively. The standardized mortality and DALY rates increased by 3.03% and 2.98% per year from 1990 to 2019. Additionally, males suffered from a higher disease burden of these three cancers attributable to smoking than females. The elderly population had a higher smoking-attributable disease burden than the younger population. ConclusionThe situation of the disease burden of bladder, prostate and kidney cancers attributable to smoking is still serious in China, which has substantial disparities in different groups. Specifically, males and the elderly are the high-risk groups for the smoking-attributable burden. Among the three cancers, bladder cancer has the highest burden and kidney cancer has the largest burden increase during 1990-2019.
ObjectiveTo develop the questionnaire and test its reliability for investigating route, prevention, and control of SARS-CoV-2 infection in medical staffs.MethodsThis questionnaire was development based on the COVID-19 relevant guidelines, official documents issued by the National Health Committee of the People's Republic of China, and published studies. The development group performed repeated discussions and drafted the first questionnaire, then performed expert consultation and revised the draft according to their suggestions. Eventually, some frontline medical staffs were invited to carry out pre-test investigation of the questionnaire and test its reliability.ResultsThe first draft included 48 items; 18 experts were invited in the first round questionnaire and 10 experts in the second round questionnaire. The positive coefficient of experts in these two rounds was both greater than 75%, and the authority coefficient of experts' opinions was greater than 0.70. The variation coefficient of these items was between 0.00 and 0.35, the coordination coefficient of experts was 0.193 (P<0.05). The experts of above two rounds put forward 14 suggestions for text modification or adjustment options of some items; after the development group held repeatedly discussions, a total of 8 items were performed secondary consultation and finally reached consensus. The final questionnaire included two domains of questionnaire before and after confirmed diagnosis. The domain "before confirmed diagnosis" covered 4 sections and 29 items involving infectious cause, plan and knowledge of prevention and control, and psychological symptoms. The domain "after confirmed diagnosis" covered 5 sections and 21 items, included symptoms, treatment, and psychological status after diagnosis; impact on the surrounding environment and people, and awareness of protection after infection. The pre-test results showed that the total items were considerably numerous, some items were difficult to understand, some laboratory results and treatment conditions were ambiguous, etc. After modification and re-testing, the test-re-test reliability of each domain was between 0.74 and 0.93, and the overall re-test reliability of the questionnaire content was 0.82.ConclusionsThis research has developed a questionnaire for investigating infection process, prevention and control of SARS-CoV-2 infection in medical staff, and the items considered two domains prior to and after confirmed diagnosis. The reliability and practicability of the questionnaire are acceptable.