Background: Survival rate is used to develop cancer control plans. However, there are limitations and biases when interpreting patient survival rate data. This study aimed to identify and account for potential biases and/or limitations on estimating survival rate to enable more effective control of cancer.
Methods: The authors searched PubMed from December 2010 to December 2015 for articles that investigated or described biases in estimating patient survival using cancer registries. Articles that only described the tendency of survival rate and investigated relationships between patient characteristics, treatment, and survival rate were excluded.
Results: In total, 50 articles met the inclusion criteria. The identified potential biases were categorized into three areas, as follows: 1) the quality of registry data (eg, the completeness of cancer patients, accuracy of data, and follow-up rates); 2) limitations related to estimated methods of survival rates (eg, misclassification of cause of death for cause-specific survival rate or a lack of comparability of background mortality for relative survival rate); and 3) the comparability of survival rates among different groups (eg, age-adjustment or patients with multiple cancers).
Conclusion: We concluded that survival rate can be suitable for answering questions related to health policy and research. Several factors should be considered when interpreting survival rates estimated using cancer registries.
Background: Japanese rice cake (“mochi”) is a major cause of food-choking accidents in Japan. However, the epidemiology of out-of-hospital cardiac arrests (OHCAs) due to suffocation caused by rice cakes is poorly understood.
Methods: OHCA data from 2005 to 2012 were obtained from the population-based OHCA registry in Osaka Prefecture. Patients aged ≥20 years who experienced OHCA caused by suffocation that occurred before the arrival of emergency-medical-service (EMS) personnel were included. Patient characteristics, prehospital interventions, and outcomes were compared based on the cause of suffocation (rice cake and non-rice-cake). The primary outcome was 1-month survival after OHCA.
Results: In total, 46 911 adult OHCAs were observed during the study period. Of the OHCAs, 7.0% (3,294/46,911) were due to suffocation, with choking due to rice cake as the cause in 9.5% of cases (314/3,294), and of these, 24.5% (77/314) occurred during the first 3 days of the New Year. In crude analysis, 1-month survival was 17.2% (54/314) in those with suffocation caused by rice cake and 13.4% (400/2,980) in those with suffocation due to other causes. In the multivariable analysis for all-cause suffocation, younger age, arrest witnessed by bystanders, and earlier EMS response time were significantly related to better 1-month survival.
Conclusion: Approximately 10% of OHCAs due to suffocation were caused by rice-cake choking, and 25% of these occurred during the first 3 days of the New Year. Further efforts for establishing preventive measures as well as improving the early recognition of choking and encouraging bystanders to call EMS sooner are needed.
Background: Medical circumstances in Japanese patients with cancer of the corpus uteri have greatly changed since the late 1990s, including the introduction of concomitant therapy with taxane and platinum. We evaluated changes in survival rates for this cancer following these advances by analyzing data from population-based cancer registries in Japan.
Methods: Data were available for 8562 cases of cancer of the corpus uteri from six prefectural cancer registries. We defined the two periods of 1993–2000 (1st period) and 2001–2006 (2nd period). Relative survival (RS) in each period was calculated to assess changes using an excess mortality model, with adjustment for age group (15–54, 55–69, and 70–99 years), extent of disease (localized, regional, and distant), and histological subtype.
Results: Overall 5-year RS improved from 77.7% in the 1st period to 80.2% in the 2nd period, with an excess hazard ratio (EHR) of 0.785 (95% confidence interval [CI], 0.705–0.873). Five-year RS significantly improved in the group aged 55–69 years, in all groups by extent of disease, and in the endometrioid adenocarcinoma group. In particular, 5-year RS significantly improved in patients with endometrioid adenocarcinoma, from 84.5% to 89.7%, with an EHR of 0.698 (95% CI, 0.560–0.870).
Conclusion: Overall 5-year RS for cancer of the corpus uteri in Japan improved from the 1990s to early 2000s. These improvements might have been aided by the comprehensive medical development of management for this cancer, including the spread of concomitant therapy with taxane and platinum as a standard adjuvant chemotherapy in the early 2000s.
Background: This study examined the annual prevalence of atrial fibrillation (AF) and its associated comorbidities, as well as the prevalence of warfarin therapy in South Korean patients with AF.
Methods: The National Health Insurance Service-National Sample Cohort database was searched for subjects aged ≥30 years diagnosed with AF from 2002–2013. The prevalence of AF was analyzed by sex and age, as was the current status of warfarin therapy in AF patients according to CHA2DS2-VASc score and comorbidities.
Results: The age-standardized prevalence of AF in men and women was 0.15% and 0.14%, respectively, in 2002, increasing to 0.54% and 0.39%, respectively, in 2013. In 2013, the prevalence of AF in men and women aged 30–39 years was 0.08% and 0.03%, respectively, increasing to 2.35% and 1.71%, respectively, in those in aged ≥60 years. During 2002–2013, the prevalence of AF in men significantly increased among subjects aged ≥30 years and increased in women aged ≥60 years. The age-standardized prevalence of hypertension and diabetes mellitus among AF patients were markedly increased during 2002–2013. Of these AF patients, 86.1% had a CHA2DS2-VASc score of ≥2; however, only 39.1% of these were receiving warfarin.
Conclusions: The age-standardized prevalence of AF increased 2.89-fold over the 12-year study period. The total number of patients with AF in South Korea has been drastically increasing, due to not only aging society but also increasing age-specific prevalence of AF, especially in middle-aged and elderly individuals. The rate of warfarin therapy increased slightly over the study period but remains low.
Background: Few studies have investigated the work continuance rate among cancer survivors after return to work (RTW). The objective of this study was to clarify work sustainability after RTW among Japanese male cancer survivors.
Methods: We collected data on male cancer survivors from an occupational health register. Inclusion criteria were as follows: employees who returned to work after an episode of sick leave due to clinically certified cancer diagnosed between January 1, 2000 and December 31, 2011.
Results: Of 1,033 male employees who were diagnosed with cancer, 786 employees (76.1%) returned to work after their first episode of sick leave due to cancer. Work continuance rates among all subjects were 80.1% 1 year after RTW and 48.5% 5 years after RTW. The mean duration of work after RTW was 4.5 years. The work continuance rates varied significantly by cancer type. The “Lung” and “Hepatic, Pancreatic” cancer groups had the shortest duration of work (0.9 year after RTW).
Conclusions: Of workers who returned to work after their first episode of leave after cancer, 50% continued to work after 5 years in large-scale companies. There was a steep decrease in work continuance rates during the first year after RTW, with considerable differences according to cancer site.
Background: Data on the effect of physical activity intensity on depression is scarce. We investigated the prospective association between intensity of leisure-time exercise and risk of depressive symptoms among Japanese workers.
Methods: The participants were 29,052 employees (24,653 men and 4,399 women) aged 20 to 64 years without psychiatric disease including depressive symptoms at health checkup in 2006–2007 and were followed up until 2014–2015. Details of leisure-time exercise were ascertained via a questionnaire. Depressive states were assessed using a 13-item questionnaire. Multivariable-adjusted hazard ratio of depressive symptoms was estimated using Cox regression analysis.
Results: During a mean follow-up of 5.8 years with 168,203 person-years, 6,847 workers developed depressive symptoms. Compared with workers who engaged in no exercise during leisure-time (0 MET-hours per week), hazard ratios (95% confidence intervals) associated with >0 to <7.5, 7.5 to <15.0, and ≥15.0 MET-hours of leisure-time exercise were 0.88 (0.82–0.94), 0.85 (0.76–0.94), and 0.78 (0.68–0.88) among workers who engaged in moderate-intensity exercise alone; 0.93 (0.82–1.06), 0.82 (0.68–0.98), and 0.83 (0.71–0.98) among workers who engaged in vigorous-intensity exercise alone; and 0.96 (0.80–1.15), 0.80 (0.67–0.95), and 0.76 (0.66–0.87) among workers who engaged in both moderate- and vigorous-intensity exercise with adjustment for age, sex, lifestyles, work-related and socioeconomic factors, and body mass index. Additional adjustment for baseline depression score attenuated the inverse association, especially among those who engaged in moderate-intensity exercise alone.
Conclusions: The results suggest that vigorous-intensity exercise alone or vigorous-intensity combined with moderate-intensity exercise would prevent depressive symptoms among Japanese workers.
Background: The Japan Environment and Children’s Study (JECS), known as Ecochil-Chosa in Japan, is a nationwide birth cohort study investigating the environmental factors that might affect children’s health and development. We report the baseline profiles of the participating mothers, fathers, and their children.
Methods: Fifteen Regional Centres located throughout Japan were responsible for recruiting women in early pregnancy living in their respective recruitment areas. Self-administered questionnaires and medical records were used to obtain such information as demographic factors, lifestyle, socioeconomic status, environmental exposure, medical history, and delivery information. In the period up to delivery, we collected bio-specimens, including blood, urine, hair, and umbilical cord blood. Fathers were also recruited, when accessible, and asked to fill in a questionnaire and to provide blood samples.
Results: The total number of pregnancies resulting in delivery was 100,778, of which 51,402 (51.0%) involved program participation by male partners. Discounting pregnancies by the same woman, the study included 95,248 unique mothers and 49,189 unique fathers. The 100,778 pregnancies involved a total of 101,779 fetuses and resulted in 100,148 live births. The coverage of children in 2013 (the number of live births registered in JECS divided by the number of all live births within the study areas) was approximately 45%. Nevertheless, the data on the characteristics of the mothers and children we studied showed marked similarity to those obtained from Japan’s 2013 Vital Statistics Survey.
Conclusions: Between 2011 and 2014, we established one of the largest birth cohorts in the world.