Use of Antiperspirant Products and Risk of Breast Cancer: A Meta-Analysis of Case-Control Studies.

Although several observational studies have reported a link between the use of underarm cosmetic products and the risk of breast cancer, the findings remain inconsistent. This study aimed to investigate these associations using a meta-analysis of observational studies. In the meta-analysis of seven case-control studies, we found no association between the use of underarm antiperspirants or deodorants and the risk of breast cancer (OR = 0.96, 95%CI 0.78-1.17; I2 = 60.0%). Further prospective cohort studies that provide a higher level of evidence are warranted to confirm our findings.

Consumption of Sugar-Sweetened Soft Drinks and Risk of Gastrointestinal Cancer: A Systematic Review and Meta-Analysis of Observational Studies.

INTRODUCTION: Previous observational studies have reported inconsistent findings on the association between consumption of sugar-sweetened soft drinks (SSSDs) and the risk of gastrointestinal (GI) cancer. This study investigated the associations between SSSD consumption and the risk of GI cancer using a systematic review and meta-analysis. METHODS: Observational epidemiological studies were searched from the PubMed and EMBASE databases until June 2021. We conducted a meta-analysis of all included studies and subgroup meta-analyses based on various factors. RESULTS: In a meta-analysis of 27 studies with nine case-control studies and 18 cohort studies, the consumption of SSSDs was modestly associated with an increased risk of GI cancer (odds ratio [OR]/relative risk [RR]: 1.08; 95% confidence interval [CI]: 1.01-1.16), with a significant positive dose-response relationship. In the subgroup meta-analysis by study design, there was a significant positive association between the consumption of SSSDs and GI cancer in cohort studies (RR: 1.11; 95% CI: 1.03-1.20; n = 18), but not in case-control studies. In the subgroup meta-analysis by type of cancer, consumption of SSSDs was significantly associated with an increased risk of colorectal cancer (OR/RR: 1.13; 95% CI: 1.07-1.19). CONCLUSIONS: This meta-analysis suggests that SSSD consumption significantly increases the risk of GI cancer, specifically colorectal cancer.

Association between seafood intake and the risk of thyroid cancer.

Background: Previous observational epidemiological studies such as case-control studies and cohort studies have reported inconsistent results regarding the associations between seafood intake and the risk of thyroid cancer. Materials and methods: We searched PubMed and EMBASE in August 2021 using keywords related to seafood intake and thyroid cancer. A pooled odds ratio (OR) or relative risk (RR) with its 95% confidence interval (CI) was calculated. Results: We included 17 observational studies with 13 case-control studies and 4 cohort studies, which included 4,309 thyroid cancer patients among 599,161 participants. In the random effects model meta-analysis of all 17 studies, we found that there was no significant association between seafood intake (highest vs. lowest intake) and the risk of thyroid cancer (OR or RR, 1.01; 95% CI: 0.86 to 1.19; I2=51.4%). Although the associations were not statistically significant, subgroup meta-analyses by study design showed opposite findings: seafood intake decreased the risk of thyroid cancer in case-control studies (OR or RR, 0.94; 95% CI: 0.74 to 1.19; I2=60.6%; n=13) but increased in cohort studies (OR or RR, 1.14; 95% CI: 0.97 to 1.35; I2=0.0%; n=4). Conclusion: The current meta-analysis of observational epidemiological studies found that that overall, there was no significant association between seafood intake and the risk of thyroid cancer. However, given that cohort studies give us a higher level of evidence than case-control studies, further prospective cohort studies are warranted to confirm the association between them.

Obesity and mortality in patients with COVID-19: A meta-analysis of prospective studies.

BACKGROUND AND OBJECTIVES: Previous prospective studies have reported inconsistent findings on the associ-ation between obesity and mortality in patients with COVID-19. This study aimed to investigate the associa-tion between them by using a meta-analysis of prospective studies. METHODS AND STUDY DESIGN: We searched PubMed and EMBASE to retrieve studies using keywords related to this topic on January 3, 2022. Data were extracted for a random-effects meta-analysis to calculate a pooled odds ratio (OR), relative risk (RR), or hazard ratio (HR) with a 95% confidence interval (CI). RESULTS: In the meta-analysis of 15 prospective cohort studies, obesity significantly increased the risk of mortality in patients with COVID-19 (OR/RR/HR, 1.52; 95% CI, 1.26 to 1.84; I2 = 90.4%). Most of the included studies were conducted in European (n = 10) and North American (n = 4) countries. In the subgroup meta-analysis by continent, there was a significant association between them in European countries (OR/RR/HR, 1.78; 95% CI, 1.30 to 2.43; I2 = 81.4%). Also, in the subgroup meta-analysis by data source, obesity was significantly associated with the increased mortality in patients with COVID-19 in both population- and hospital-based data. CONCLUSIONS: We found that obesity is associated with the increased risk of mortality in patients of COVID-19.

Effects of intermittent or single high-dose vitamin D supplementation on risk of falls and fractures: a systematic review and meta-analysis.

Previous randomized controlled trials have reported inconsistent findings regarding the effects of high-dose vitamin D supplementation on a risk of falls and fractures. This meta-analysis of 15 trials shows that intermittent or single high-dose vitamin D supplementation had no preventive effect on the risk of falls and fractures and might even increase the risk of falls. PURPOSE: Randomized controlled trials (RCTs) have reported controversial findings regarding the associations between intermittent or single high-dose vitamin D supplementation and a risk of falls and fractures in adults. This study aimed to investigate those associations using a systematic review and meta-analysis. METHODS: We searched PubMed, EMBASE, and Cochrane Library from inception to May 25, 2022. Data were extracted for a random-effects meta-analysis to calculate a pooled relative risk (RR) with a 95% confidence interval (CI). RESULTS: Out of 527 articles, a total of 15 RCTs were included in the final analysis. In a meta-analysis of RCTs, intermittent or single high-dose vitamin D supplementation showed no significant beneficial effect in the prevention of either falls (RR, 1.03 [95% CI, 0.98-1.09]; I2 = 56.6%; n = 11) or fractures (RR, 0.99 [95% CI, 0.87-1.14]; I2 = 48.3%; n = 11). Among the subgroup meta-analyses by various factors, intermittent or single high-dose vitamin D supplementation reduced the risk of fractures in the subgroup meta-analysis of RCTs that included fewer than 1000 participants (RR, 0.74 [95% CI 0.57-0.96]; I2 = 0.0%; n = 5). However, its beneficial effect was not observed in those including 1000 or more participants (RR, 1.06 [95% CI 0.92-1.21]; I2 = 57.5%; n = 6). In contrast, intermittent or single high-dose vitamin D3 supplementation increased the risk of falls on the borderline of statistical significance (RR, 1.06 [95% CI 0.99-1.15]; P = 0.051; I2 = 50.0%; n = 7). CONCLUSIONS: Intermittent or single high-dose vitamin D supplementation had no preventive effect on the risk of falls and fractures and might even increase the risk of falls.

Exposure to Electronic Cigarette Advertisements and Use of Electronic Cigarettes: A Meta-analysis of Prospective Studies.

INTRODUCTION: Electronic cigarette (EC) advertisements remain unregulated and approach consumers in TV commercials, print ads, radio, and other forms of digital marketing. AIMS AND METHODS: This study aimed to assess whether exposure to EC advertisements is associated with the use of EC by using a meta-analysis of prospective studies. We searched PubMed, EMBASE, and Web of Science to locate eligible studies in November 2021. Pooled adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were calculated using a random-effects meta-analysis. RESULTS: Out of 1635 articles searched from databases, we included seven prospective studies that met inclusion criteria in the final analysis. Four out of seven studies involved participants under 18 years of age. In the meta-analysis of all studies, exposure to EC advertisements was significantly associated with the increased use of ECs (aOR = 1.53, 95% CI 1.22 to 1.92; I2 = 60.1%). In the subgroup meta-analyses by source of advertisements, there was no significant association between exposure to EC advertisements on TV, radio, or billboards and the use of EC, while exposure to EC advertisements in retail stores and on Internet or social media significantly increased the use of EC. CONCLUSIONS: Exposure to EC advertisements was associated with the increased use of ECs, specifically in retail stores and on Internet or social media among adolescents and young adults. Because EC use could serve as a gateway to cigarette smoking in adolescents and young adults, more strict regulations and restrictions on EC advertisements are needed. IMPLICATIONS: Concurrent with the rise in electronic cigarette (EC) sales, advertising expenditures for ECs have been increased in the past decade, and there is controversy over the association between exposure to EC advertisements and the use of ECs. This meta-analysis of seven prospective studies showed that exposure to EC advertisements was significantly associated with the increased use of ECs, specifically in retail stores and on Internet or social media among adolescents and young adults. Because, EC use could serve as a gateway to cigarette smoking in adolescents and young adults, more strict regulations and restrictions on EC advertisements are needed.

Oral contraceptives and risk of breast cancer and ovarian cancer in women with a BRCA1 or BRCA2 mutation: a meta-analysis of observational studies.

It remains inconclusive whether the use of oral contraceptives (OCs) alters the risks of breast or ovarian cancer in women with a breast cancer susceptibility gene 1 (BRCA1) or breast cancer susceptibility gene 2 (BRCA2) mutation. We investigated the association between OC use and the risks of breast or ovarian cancer in this group by using a meta-analysis. PubMed and EMBASE were searched using keywords until February 2021 to identify relevant studies that evaluated the association between OC ever use and the risks of breast or ovarian cancer in women with a BRCA1 or BRCA2 mutation. Twelve studies for breast cancer and eight studies for ovarian cancer were identified. In the random-effects meta-analysis, the ever use of OCs was significantly associated with an increased risk of breast cancer [odds ratio (OR), relative risk (RR) or hazard ratio (HR) = 1.24; 95% confidence interval (CI) 1.08-1.41] and a decreased risk of ovarian cancer (OR/RR/HR = 0.53, 95% CI 0.41-0.67). Consistent findings were observed when BRCA1 and BRCA2 mutation carriers were analyzed separately. The increased risk of breast cancer was observed only in the long-term (>5 years) users of OCs, while the decreased risk of ovarian cancer was observed regardless of the duration of OC use. The current study suggests that the ever use of OCs in BRCA mutation carriers is significantly associated with an increased risk of breast cancer and a decreased risk of ovarian cancer. Therefore, the use of OCs as chemoprevention of ovarian cancer should be cautious in BRCA mutation carriers.

Coffee Intake and Risk of Hypertension: A Meta-Analysis of Cohort Studies.

BACKGROUND: It remains unclear whether coffee intake is associated with the risk of hypertension. This study aimed to investigate the association between coffee intake and the risk of hypertension by using a meta-analysis of cohort studies. METHODS: PubMed and Embase were searched using keywords in September 2022 to identify studies on coffee intake and the risk of hypertension. RESULTS: We included a total of 13 longitudinal cohort studies, which involved a total of 64,650 incident cases of hypertension among 314,827 participants. In a random effects model meta-analysis of all the studies, coffee intake was not significantly associated with the risk of hypertension (relative risk [RR], 0.97; 95% confidence interval [CI], 0.90­1.05; I² = 58.0%; n = 13). In the subgroup meta-analysis, coffee intake was associated with a decreased risk of hypertension in studies conducted in America (RR, 0.93; 95% CI, 0.87-0.98; I² = 4.6%; n = 5) and in low-quality studies (RR, 0.92; 95% CI, 0.88-0.96; I² = 0.0%; n = 7). In the remaining subgroup meta-analyses by amount of coffee intake, gender, type of coffee (decaffeinated vs. caffeinated), smoking, and years of follow-up, coffee intake was not significantly associated with the risk of hypertension. CONCLUSION: The current meta-analysis showed that coffee intake is not associated with the risk of hypertension.

Effects of Mindfulness-Based Interventions on Mental Health in Nurses: A Meta-Analysis of Randomized Controlled Trials.

Mindfulness as a positive mental health intervention approach has been increasingly applied to nurses. This meta-analysis evaluated the psychological effects of mindfulness-based interventions (MBIs) on mental health in nurses. We searched PubMed, EMBASE, Cochrane, and CINAHL up to February 2020. Randomized controlled trials (RCTs) evaluating the effects of MBIs for nurses were included. Data extraction and the risk of bias assessment were conducted by two authors independently. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated using a random-effects meta-analysis. Of 370 studies retrieve from databases, nine RCTs, which involved 572 participants with 283 in an intervention group and 289 in a control group, were included in the final analysis. Compared to the control groups (no treatment, treatment as usual, or active control), MBIs reduced psychological distress such as anxiety, depression, or stress (SMD = -0.47; 95% CI, -0.67 to -0.32; I2 = 34.7; n = 17) in nurses. Also, MBIs slightly improved psychological wellbeing such as resilience, wellbeing, or quality of life (SMD = 0.28; 95% CI, 0.11 to 0.46; I2 = 0.00; n = 8). However, no statistically significant effects were found in Job related outcomes (SMD = 0.23; 95% CI, -0.01 to 0.47; I2 = 20.5; n = 6). This meta-analysis found that MBIs had beneficial effects on mental health such as psychological distress and wellbeing in nurses.

Night shift work and breast cancer risk: a meta-analysis of observational epidemiological studies.

Previous observational epidemiological studies have reported inconsistently the association between night shift work (NSW) and the risk of breast cancer (BC). This study aimed to investigate those associations by using a meta-analysis of observational epidemiological studies. We searched PubMed and EMBASE using keywords related to this topic from inception till November 2020. The pooled effect sizes such as odds ratio (OR), hazard ratio (HR) or relative risk (RR) with 95% confidence interval (CI) were calculated using a random-effects model. In the meta-analysis of a total of 32 observational studies including 13 case-control studies, 4 nested case-control studies and 15 cohort studies, NSW significantly increased the risk of BC (OR/RR/HR, 1.11; 95% CI, 1.04-1.20; I2 = 72.4%). In the subgroup meta-analysis by type of study, NSW was also associated with the increased risk of BC in case-control studies (OR, 1.34; 95% CI, 1.17-1.53; I2 = 63.8%). However, no significant association was found in both nested case-control studies (OR, 1.14; 95% CI, 0.89-1.46; I2 = 65.8%) and cohort studies (RR/HR, 0.98; 95% CI, 0.93-1.03; I2 = 25.3%). Besides, there was no significant association between NSW for over 20 years and the risk of BC (OR/RR/HR, 1.03; 95% CI, 0.95-1.11; I2 = 36.6%, n = 14). Given that cohort studies provide higher evidence than case-control studies, there is no association between NSW and the risk of BC.

Consumption of artificially sweetened soft drinks and risk of gastrointestinal cancer: a meta-analysis of observational studies.

OBJECTIVE: There remain inconclusive findings from previous observational epidemiological studies on whether consumption of artificially sweetened soft drinks (ASSD) increases the risk of gastrointestinal (GI) cancer. We investigated the associations between the consumption of ASSD and the risk of GI cancer using a meta-analysis. DESIGN: Systematic review and meta-analysis. SETTING: PubMed and EMBASE were searched using keywords until May 2020 to identify observational epidemiological studies on the association between the consumption of ASSD and the risk of GI cancer. SUBJECTS: Twenty-one case-control studies and seventeen cohort studies with 12 397 cancer cases and 2 474 452 controls. RESULTS: In the random-effects meta-analysis of all the studies, consumption of ASSD was not significantly associated with the risk of overall GI cancer (OR/relative risk (RR), 1·02; 95 % CI, 0·92, 1·14). There was no significant association between the consumption of ASSD and the risk of overall GI cancer in the subgroup meta-analyses by study design (case-control studies: OR, 0·95; 95 % CI, 0·82, 1·11; cohort studies: RR, 1·14; 95 % CI, 0·97, 1·33). In the subgroup meta-analysis by type of cancer, consumption of ASSD was significantly associated with the increased risk of liver cancer (OR/RR, 1·28; 95 % CI, 1·03, 1·58). CONCLUSIONS: The current meta-analysis of observational epidemiological studies suggests that overall, there is no significant association between the consumption of ASSD and the risk of GI cancer.

A Health Information Quality Assessment Tool for Korean Online Newspaper Articles: Development Study.

BACKGROUND: Concern regarding the reliability and accuracy of the health-related information provided by online newspaper articles has increased. Numerous criteria and items have been proposed and published regarding the quality assessment of online information, but there is no standard quality assessment tool available for online newspapers. OBJECTIVE: This study aimed to develop the Health Information Quality Assessment Tool (HIQUAL) for online newspaper articles. METHODS: We reviewed previous health information quality assessment tools and related studies and accordingly developed and customized new criteria. The interrater agreement for the new assessment tool was assessed for 3 newspaper articles on different subjects (colorectal cancer, obesity genetic testing, and hypertension diagnostic criteria) using the Fleiss κ and Gwet agreement coefficient. To compare the quality scores generated by each pair of tools, convergent validity was measured using the Kendall τ ranked correlation. RESULTS: Overall, the HIQUAL for newspaper articles comprised 10 items across 5 domains: reliability, usefulness, understandability, sufficiency, and transparency. The interrater agreement for the article on colorectal cancer was in the moderate to substantial range (Fleiss κ=0.48, SE 0.11; Gwet agreement coefficient=0.74, SE 0.13), while for the article introducing obesity genetic testing it was in the substantial range, with values of 0.63 (SE 0.28) and 0.86 (SE 0.10) for the two measures, respectively. There was relatively low agreement for the article on hypertension diagnostic criteria at 0.20 (SE 0.10) and 0.75 (SE 0.13), respectively. Validity of the correlation assessed with the Kendall τ showed good correlation between tools (HIQUAL vs DISCERN=0.72, HIQUAL vs QUEST [Quality Evaluation Scoring Tool]=0.69). CONCLUSIONS: We developed a new assessment tool to evaluate the quality of health information in online newspaper articles, to help consumers discern accurate sources of health information. The HIQUAL can help increase the accuracy and quality of online health information in Korea.

Gynecological cancer and omega-3 fatty acid intakes: Meta-analysis.

BACKGROUND AND OBJECTIVES: Previous observational epidemiological studies have reported inconsistent findings on the association between dietary intake of omega-3 fatty acids and endocrine-related gynecological cancer including ovarian cancer and endometrial cancer. This study aimed to investigate this association using a metaanalysis of observational studies. METHODS AND STUDY DESIGN: We searched PubMed, EMBASE, and Cochrane library by using keywords related to the topic in December 2019. The pooled odd ratios (pORs), pooled relative risks (pRRs), or pooled hazard ratios (pHRs) with 95% confidence intervals (CIs) were calculated based on a random- effects model. Also, we performed subgroup analyses by methodological quality, type of cancer, study design, and type of omega-3 fatty acids. RESULTS: A total of 10 observational studies with six case-control and four prospective cohort studies were included in the current meta-analysis. In the meta-analysis of all studies, dietary intake of omega-3 fatty acids was not significantly associated with the risk of endometrial and ovarian cancers (pOR/HR, 0.87; 95% CI, 0.73-1.04; I2=67.2%) (highest versus lowest intake). In the subgroup analysis by type of study, no significant association was found in cohort studies (pHR, 1.03; 95% CI, 0.63-1.67, I2=81.9%), whereas dietary intake of omega-3 fatty acids was associated with the decreased risk of endocrine-related gynecological cancers in case-control studies (pOR, 0.81; 95% CI, 0.67 to 0.98, I2=55.7%). CONCLUSIONS: The current metaanalysis of observational studies suggests that dietary intake of omega-3 fatty acids is not significantly associated with the risk of endocrine-related gynecological cancer.

Efficacy of Pharmacotherapy for Smoking Cessation in Adolescent Smokers: A Meta-analysis of Randomized Controlled Trials.

INTRODUCTION: This study aimed to evaluate the efficacy of pharmacotherapy for smoking cessation among adolescent smokers by using a meta-analysis of randomized controlled trials (RCTs). METHODS: PubMed, EMBASE, and Cochrane Library were searched from the inception to January 20, 2018. We included RCTs of pharmacotherapy for smoking cessation among adolescent smokers aged less than 20 years. Data were pooled using a random-effects meta-analysis. The primary outcome measures were a smoking abstinence rate and its relative risk (RR) at the longest follow-up period in each study validated by biochemical markers. RESULTS: Among a total of 1035 articles searched, nine RCTs, which involved 1188 adolescent smokers aged 12-20 years with 627 in the intervention group and 561 in the control group, were included in the final analysis. In the random-effects meta-analysis of all the nine trials, pharmacotherapy showed a increased abstinence rate (RR = 1.62; 95% confidence interval [CI] = 1.08 to 2.44, I2 = 0.0%), compared with the control group. Subgroup meta-analyses by follow-up period showed an increased abstinence rate at 4 weeks (RR = 1.87; 95% CI = 1.22 to 2.87; n = 4) and a nonsignificantly increased abstinence rate during the longer term follow-up periods at 8, 12, 24, and 52 weeks. CONCLUSIONS: The current meta-analysis suggests that pharmacotherapy can be considered as an aid for smoking cessation in the short-term period among adolescent smokers. However, further large RCTs are warranted to determine its long-term efficacy and safety. IMPLICATIONS: In this meta-analysis of nine RCTs with 1188 adolescent smokers aged 12-20 years, pharmacotherapy showed an increased abstinence rate, compared with the control group. In the subgroup meta-analyses by follow-up period, it showed the increased abstinence rate at 4 weeks and no efficacy on abstinence during the longer term follow-up periods up to 52 weeks. Further large RCTs are warranted to determine the long-term efficacy and safety of pharmacotherapy in adolescent smokers.

Type 1 diabetes mellitus and risk of cancer: a meta-analysis of observational studies.

OBJECTIVE: Previous observational studies have focused on the link between type 2 diabetes and the risk of cancer. However, the association between type 1 diabetes and the risk of cancer has not been well addressed. This study aimed to investigate the association between type 1 diabetes and the risk of cancer by using a meta-analysis of observational studies. METHODS: We searched PubMed and EMBASE for observational studies that examined the association between type 1 diabetes and cancer in April 2017. We calculated the pooled odds ratios (ORs) or relative risks (RRs) with confidence intervals (CIs) from individual studies based on a random-effects model meta-analysis. RESULTS: We included a total of 15 observational studies with two case-control studies and 13 cohort studies involving 31 893 cancer patients among a total of 1 915 179 participants in the final analysis. In the random-effects meta-analysis of all studies, patients with type 1 diabetes had an increased risk of cancer (OR or RR, 1.29; 95% CI, 1.09-1.52; n = 15; I2 = 95.2%). In the subgroup meta-analysis by type of cancer, type 1 diabetes significantly increased the risk of cancers of stomach, lung, pancreas, liver, ovary and kidney, whereas it significantly decreased the risk of breast cancer (OR or RR, 0.91; 95% CI, 0.86-0.95; n = 9; I2 = 0%). CONCLUSION: This meta-analysis suggests that type 1 diabetes is associated with the increased risk of several types of cancer and the decreased risk of breast cancer. However, the plausible mechanisms for the decreased risk of breast cancer remain unclear. Further prospective studies with proper adjustment for possible confounding factors are warranted.

Use of benzodiazepine and risk of cancer: A meta-analysis of observational studies.

Several observational epidemiological studies have reported inconsistent results on the association between the use of benzodiazepine and the risk of cancer. We investigated the association by using a meta-analysis. We searched PubMed, EMBASE, and the bibliographies of relevant articles to locate additional publications in January 2016. Three evaluators independently reviewed and selected eligible studies based on predetermined selection criteria. Of 796 articles meeting our initial criteria, a total of 22 observational epidemiological studies with 18 case-control studies and 4 cohort studies were included in the final analysis. Benzodiazepine use was significantly associated with an increased risk of cancer (odds ratio [OR] or relative risk [RR] 1.19; 95% confidence interval 1.16-1.21) in a random-effects meta-analysis of all studies. Subgroup meta-analyses by various factors such as study design, type of case-control study, study region, and methodological quality of study showed consistent findings. Also, a significant dose-response relationship was observed between the use of benzodiazepine and the risk of cancer (p for trend <0.01). The current meta-analysis of observational epidemiological studies suggests that benzodiazepine use is associated with an increased risk of cancer.

Effects of Vitamin and Antioxidant Supplements in Prevention of Bladder Cancer: a Meta-Analysis of Randomized Controlled Trials.

This study aimed to investigate the effects of vitamin and antioxidant supplements in the prevention of bladder cancer using a meta-analysis of randomized controlled trials (RCTs). Fourteen RCTs were included in the final analysis. In a fixed-effect meta-analysis, vitamin and antioxidant supplements showed no preventive effect for bladder cancer (relative risk [RR] = 1.04; 95% confidence interval [CI] 0.92-1.17; I² = 39.7%). Also, there was no preventive effect of these supplements in the subgroup meta-analyses by various factors such as type of supplements, type of cancer prevention, methodological quality, providers of supplements, type of control group, and number of participants. Among the subgroup analyses by type of supplements, beta-carotene supplementation alone marginally increased the risk of bladder cancer (RR = 1.44; 95% CI 1.00-2.09; I² = 0.0%; n = 3). The current meta-analysis found that vitamin and antioxidant supplements have no preventive effect against bladder cancer.

Night Shift Work and Risk of Depression: Meta-analysis of Observational Studies.

This study aimed to assess whether night shift work is associated with the risk of depression by using a meta-analysis of observational studies. We searched PubMed and EMBASE in August, 2016 to locate eligible studies and investigated the association between night shift work and the risk of depression, reporting outcome measures with adjusted odds ratios (ORs) or relative risks (RRs) and 95% confidence intervals (CIs). In the meta-analysis of a total of 11 observational studies with 9 cross-sectional study, 1 longitudinal study, and 1 cohort study, night shift work was significantly associated with an increased risk of depression (OR/RR, 1.43; 95% CI, 1.24-1.64; I² = 78.0%). Also, subgroup meta-analyses by gender, night shift work duration, type of occupation, continent, and type of publication showed that night shift work was consistently associated with the increased risk of depression. The current meta-analysis suggests that night shift work is associated with the increased risk of depression. However, further large prospective cohort studies are needed to confirm this association.

Longer Duration of Sleep and Risk of Cognitive Decline: A Meta-Analysis of Observational Studies.

BACKGROUND: Previous observational epidemiological studies have reported inconsistent findings about the association between longer durations of sleep and the risk of cognitive impairment and dementia. To investigate the association between longer durations of sleep and the risk of cognitive decline, we performed a meta-analysis of observational studies. METHODS: We searched PubMed, EMBASE, and the bibliographies of relevant articles to retrieve additional studies in July 2015. A total of 53,942 participants (mean age 66.9 years) were included in the final analysis. Three evaluators independently reviewed and selected articles, based on pre-determined selection criteria. RESULTS: Among a total of 695 articles, 10 observational epidemiological studies with 3 case-control studies and 7 cohort studies were included in the final analysis. Compared to the average sleep duration, the odds ratio or relative risk of the longest sleep duration was 1.42 (95% CI 1.27-1.59) for cognitive decline in the fixed-effect meta-analysis, 1.38 for cognitive impairment (95% CI 1.23-1.56), and 1.42 for dementia (95% CI 1.15-1.77). Subgroup meta-analyses by various factors such as study design, type of cognitive decline, gender, region, age, and methodological quality of study showed consistent findings. CONCLUSION: The current meta-analysis found that longer duration of sleep is associated with an increased risk of cognitive decline.

Efficacy of Ginseng Supplements on Fatigue and Physical Performance: a Meta-analysis.

We conducted a meta-analysis to investigate the efficacy of ginseng supplements on fatigue reduction and physical performance enhancement as reported by randomized controlled trials (RCTs). RCTs that investigated the efficacy of ginseng supplements on fatigue reduction and physical performance enhancement compared with placebos were included. The main outcome measures were fatigue reduction and physical performance enhancement. Out of 155 articles meeting initial criteria, 12 RCTs involving 630 participants (311 participants in the intervention group and 319 participants in the placebo group) were included in the final analysis. In the fixed-effect meta-analysis of four RCTs, there was a statistically significant efficacy of ginseng supplements on fatigue reduction (standardized mean difference, SMD = 0.34; 95% confidence interval [CI] = 0.16 to 0.52). However, ginseng supplements were not associated with physical performance enhancement in the fixed-effect meta-analysis of eight RCTs (SMD = -0.01; 95% CI = -0.29 to 0.27). We found that there was insufficient clinical evidence to support the use of ginseng supplements on reducing fatigue and enhancing physical performance because only few RCTs with a small sample size have been published so far. Further lager RCTs are required to confirm the efficacy of ginseng supplements on fatigue reduction.