Introduction: Relative or absolute safety of heated tobacco products (HTPs) remains unknown, while independent literature suggests that these products do not favor tobacco control. We conducted a comprehensive systematic review and meta-analysis to evaluate HTP usage patterns and the effect of HTP use on conventional tobacco smoking (use transitions).

Methods: We used Pubmed/MEDLINE, Embase, and the Cochrane Library to identify all articles published up to February 2022 on HTP use. For the present review, we included all representative cross-sectional studies dealing with HTP use, and all prospective cohort studies or cross-sectional studies on conventional tobacco smoking transitions due to HTP use. From 610 non-duplicate articles, 76 were eligible (71 cross-sectional and 5 prospective cohort studies).

Results: Compared with young adults, HTP use was less frequent among middle-aged (15 studies; pooled odds ratio [OR] 0.59; 95% confidence interval [CI], 0.48–0.74) and older adults (12 studies; OR 0.17; 95% CI, 0.07–0.38). HTP use was more frequent among former (6 studies; OR 2.73; 95% CI, 1.03–7.25) and current smokers (12 studies; OR 14.53; 95% CI, 6.34–33.31). Overall, 68.3% of HTP users were dual users (n = 26). Eight studies (including 5 cohorts) showed that HTP users were more likely than non-users to start conventional cigarette smoking (2 studies; OR 6.31; 95% CI, 4.13–9.65), whereas current cigarette smokers using HTPs were less likely to quit (4 studies; OR 0.84; 95% CI, 0.80–0.89).

Conclusion: We found that HTPs are specifically popular among young generations. More than two out of three HTP users are dual users. Prospective studies consistently show that, in real life, HTPs are not effective smoking-cessation tools.

Background: Multiple tobacco product (MTP) use is a public health concern due to their combined adverse health effects. MTP use may have increased since heated tobacco products (HTPs) became more prevalent in Japan. This study aimed to (1) estimate the recent prevalence of MTP use and clarify the associated factors compared to (2) non-smokers and (3) single-product users.

Methods: We used data from an internet survey conducted in February 2022. The prevalence of MTP use in Japan was estimated using inverse probability-weighted scores from this survey and a nationwide survey by the Japanese government. Tobacco products include six types: cigarettes, HTPs, e-cigarettes, cigars, pipe/water pipes, and smokeless tobacco products. MTP use was defined using the outcome variable (no use, single-product use, and MTP use) based on these six types of use. Using multivariate logistic regression, we calculated the adjusted odds ratios and 95% confidence intervals (CI) to clarify factors associated with MTP use compared to non-smokers, adjusting demographic variables, psychological distress, self-rated health, and alcohol use. Using multivariate Poisson regression, we calculated the adjusted prevalence ratios (aPRs) and 95% CIs to clarify factors associated with MTP use among smokers, adjusting for these covariates and smoking-related factors like workplace and home smoking rules.

Results: We analyzed 30,141 participants whose mean age was 47.8 years (standard deviation, 17.9), and 14,722 participants were male (48.8%). The estimated prevalence of MTP use was 6.8%. The most common combination of MTP use was cigarettes and HTPs. Compared to non-smokers, being younger, male, alcohol drinkers, and having low education, poor psychological distress, and poor self-rated health were factors associated with MTP use. Among smokers, workplace smoking rules, such as a partial smoking ban and no smoking ban, were not associated with MTP use compared to the indoor smoking ban. However, having no home smoking ban was positively associated with MTP use compared with a ban on both cigarettes and HTPs at home (both cigarettes and HTPs allowed aPR 1.36; 95% CI, 1.15–1.61, HTPs only allowed aPR 1.73; 95% CI, 1.43–2.10).

Conclusion: MTP users may account for a high percentage of Japanese smokers.

Background: Spontaneous pregnancy loss (SPL) precedes an increased risk of reduced fertility, while its etiology mechanism remains largely unknown. Liver dysfunction presenting in early pregnancy may represent a pre-existing undiagnosed liver condition affecting fetal development. Here, we investigated whether maternal abnormal liver function in early pregnancy contributed to the incidence of SPL.

Methods: Data on pregnant women were leveraged from the Maternal Health Care Information System in Shanghai City from 2017 to 2021. Liver dysfunction status was defined as having any elevated liver function biomarker levels (LFBs) at the first antenatal visit. SPL cases were defined as fetal death occurring before 28 weeks gestation. Generalized linear models were used to estimate crude and adjusted risk ratios (RRs and aRRs, respectively) and 95% confidence intervals (CIs).

Results: Among 10,175 leveraged pregnant women, 918 (9.0%) SPL cases were recorded. Maternal liver dysfunction in early pregnancy was associated with a 49% increased risk of SPL (RR 1.49; 95% CI, 1.22–1.84). This positive association persisted after adjustment for covariates (aRR 1.55; 95% CI, 1.26–1.92). Higher γ-glutamyl transferase (GGT) and alkaline phosphatase (ALP) levels were also linked with increased risk of SPL in a linear fashion (aRRs per 1 standard deviation increase: 1.13; 95% CI, 1.08–1.17 and 1.13; 95% CI, 1.07–1.20, respectively). Similar magnitudes of associations were observed between normal weight and overweight pregnant women in subgroup analysis.

Conclusion: We provide new evidence that maternal abnormal liver function in early pregnancy, as well as GGT and ALP, predisposes to an increased risk of SPL.

Background: With global aging, especially in Asia, preventing pneumonia among seniors is vital. The necessity of introducing pneumococcal vaccines among the elderly has been highlighted, but there is a paucity of community-based real-world evidence on their effect. Sera Town in Hiroshima Prefecture, a super-aged community, launched a distinctive pneumococcal vaccination support project for elderly residents and conducted a 5-year follow-up survey. This study evaluates the effectiveness of this vaccination initiative.

Methods: From October 2010 to March 2015, Sera Town recruited elderly residents for PPSV23 vaccination with partial cost subsidies. Participants were surveyed annually for 5 years post-vaccination to assess pneumonia incidence, calculated on a person-years basis. Using vital statistics from 2000 to 2016, we quantified changes in mortality rates associated with the vaccination support project through an interrupted-time-series analysis.

Results: Of approximately 7,900 residents aged 65 and older, 3,422 (43%) participated in the project (median age: 84 years; range: 70–114 years; 56.7% female). Over 14,559 person-years of observation, 295 participants developed pneumonia. The post-vaccination incidence rate was 20.3 per 1,000 person-years (95% confidence interval [CI], 18.0–22.7). Interrupted time series analysis indicated a 25% reduction in Sera Town’s pneumonia mortality rate post-project, reversing an annual increase of 0.23 per 1,000 population pre-project to an annual decrease of 0.04 per 1,000 population post-project.

Conclusion: This study provided real-world evidence on the association with PPSV23 vaccination on the general elderly through a community-based study. The results may be particularly useful for regions where PPSV23 serotypes are prevalent, offering insights for areas facing aging challenges.

Background: Japan’s stringent licensing policies for older drivers have not been questioned, possibly due to negative perceptions of older drivers potentially influenced by media coverage of their car crashes. We examined whether older drivers’ fatal crashes are over-represented in news articles.

Methods: To examine the news coverage of fatal crashes that occurred between January 2016 and December 2020, we extracted driver- and crash-related data from articles reporting fatal crashes in the two best-selling newspapers, Yomiuri and Asahi. We obtained the corresponding data of police-reported fatal crashes during the same period. We calculated the proportion of newspaper-reported fatal crashes to police-reported fatal crashes by at-fault driver’s age group and crash characteristics.

Results: Of 12,987 police-reported fatal crashes, 5,888 (45%) and 2,909 (22%) crashes were reported in Yomiuri and Asahi newspapers, respectively. Excluding 2,098 crashes where at-fault drivers or their ages were not identifiable, Yomiuri reported 39%, 35%, and 31%, and Asahi reported 20%, 16%, and 14% of fatal crashes caused by drivers aged <30 years, 30–69 years, and 70 years or older, respectively. Crashes that caused more fatalities or killed children tended to be reported regardless of at-fault drivers’ age groups. Compared with young and middle-aged drivers, older drivers’ fatal crashes involving child fatalities were more often reported, whereas their single fatal crashes ending in their own deaths were less often reported.

Conclusion: Older drivers’ at-fault fatal crashes were not over-represented in the news coverage of overall fatal crashes, and their crashes killing themselves were under-reported.