ABO Blood Group and Risk of Thromboembolic and Arterial Disease: A Study of 1.5 Million Blood Donors.

BACKGROUND: ABO blood groups have been shown to be associated with increased risks of venous thromboembolic and arterial disease. However, the reported magnitude of this association is inconsistent and is based on evidence from small-scale studies. METHODS AND RESULTS: We used the SCANDAT2 (Scandinavian Donations and Transfusions) database of blood donors linked with other nationwide health data registers to investigate the association between ABO blood groups and the incidence of first and recurrent venous thromboembolic and arterial events. Blood donors in Denmark and Sweden between 1987 and 2012 were followed up for diagnosis of thromboembolism and arterial events. Poisson regression models were used to estimate incidence rate ratios as measures of relative risk. A total of 9170 venous and 24 653 arterial events occurred in 1 112 072 individuals during 13.6 million person-years of follow-up. Compared with blood group O, non-O blood groups were associated with higher incidence of both venous and arterial thromboembolic events. The highest rate ratios were observed for pregnancy-related venous thromboembolism (incidence rate ratio, 2.22; 95% confidence interval, 1.77-2.79), deep vein thrombosis (incidence rate ratio, 1.92; 95% confidence interval, 1.80-2.05), and pulmonary embolism (incidence rate ratio, 1.80; 95% confidence interval, 1.71-1.88). CONCLUSIONS: In this healthy population of blood donors, non-O blood groups explain >30% of venous thromboembolic events. Although ABO blood groups may potentially be used with available prediction systems for identifying at-risk individuals, its clinical utility requires further comparison with other risk markers.

Helicobacter pylori infection, chronic corpus atrophic gastritis and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort: A nested case-control study.

The association between H. pylori infection and pancreatic cancer risk remains controversial. We conducted a nested case-control study with 448 pancreatic cancer cases and their individually matched control subjects, based on the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, to determine whether there was an altered pancreatic cancer risk associated with H. pylori infection and chronic corpus atrophic gastritis. Conditional logistic regression models were applied to calculate odds ratios (ORs) and corresponding 95% confidence intervals (CIs), adjusted for matching factors and other potential confounders. Our results showed that pancreatic cancer risk was neither associated with H. pylori seropositivity (OR = 0.96; 95% CI: 0.70, 1.31) nor CagA seropositivity (OR = 1.07; 95% CI: 0.77, 1.48). We also did not find any excess risk among individuals seropositive for H. pylori but seronegative for CagA, compared with the group seronegative for both antibodies (OR = 0.94; 95% CI: 0.63, 1.38). However, we found that chronic corpus atrophic gastritis was non-significantly associated with an increased pancreatic cancer risk (OR = 1.35; 95% CI: 0.77, 2.37), and although based on small numbers, the excess risk was particularly marked among individuals seronegative for both H. pylori and CagA (OR = 5.66; 95% CI: 1.59, 20.19, p value for interaction < 0.01). Our findings provided evidence supporting the null association between H. pylori infection and pancreatic cancer risk in western European populations. However, the suggested association between chronic corpus atrophic gastritis and pancreatic cancer risk warrants independent verification in future studies, and, if confirmed, further studies on the underlying mechanisms.

No evidence of transmission of chronic lymphocytic leukemia through blood transfusion.

Monoclonal B-cell lymphocytosis (MBL) is a precursor of chronic lymphocytic leukemia (CLL). Observations of MBL in blood donors raise concern that transmitted MBL may cause recipient CLL. Using a database with health information on 1.5 million donors and 2.1 million recipients, we compared CLL occurrence among 7413 recipients of blood from 796 donors diagnosed with CLL after donation cessation, and among 80, 431 recipients of blood from 7477 matched CLL-free donors. During follow-up, 12 and 107 cases of CLL occurred among the exposed and unexposed recipients, respectively, yielding a relative risk of 0.94 (95% confidence interval, 0.52-1.71). Analyses using the entire database showed no evidence of CLL clustering among recipients of blood from individual donors. In conclusion, when donor MBL was approximated by subsequent donor CLL diagnosis, data from 2 countries' entire computerized transfusion experience over more than 30 years indicate that MBL/CLL transmission does not contribute importantly to recipient CLL risk.

Transmission of Neurodegenerative Disorders Through Blood Transfusion: A Cohort Study.

BACKGROUND: The aggregation of misfolded proteins in the brain occurs in several neurodegenerative disorders. Aberrant protein aggregation is inducible in rodents and primates by intracerebral inoculation. Possible transfusion transmission of neurodegenerative diseases has important public health implications. OBJECTIVE: To investigate possible transfusion transmission of neurodegenerative disorders. DESIGN: Retrospective cohort study. SETTING: Nationwide registers of transfusions in Sweden and Denmark. PARTICIPANTS: 1 465 845 patients who received transfusions between 1968 and 2012. MEASUREMENTS: Multivariable Cox regression models were used to estimate hazard ratios for dementia of any type, Alzheimer disease, and Parkinson disease in patients receiving blood transfusions from donors who were later diagnosed with any of these diseases versus patients who received blood from healthy donors. Whether excess occurrence of neurodegenerative disease occurred among recipients of blood from a subset of donors was also investigated. As a positive control, transmission of chronic hepatitis before and after implementation of hepatitis C virus screening was assessed. RESULTS: Among included patients, 2.9% received a transfusion from a donor diagnosed with one of the studied neurodegenerative diseases. No evidence of transmission of any of these diseases was found, regardless of approach. The hazard ratio for dementia in recipients of blood from donors with dementia versus recipients of blood from healthy donors was 1.04 (95% CI, 0.99 to 1.09). Corresponding estimates for Alzheimer disease and Parkinson disease were 0.99 (CI, 0.85 to 1.15) and 0.94 (CI, 0.78 to 1.14), respectively. Hepatitis transmission was detected before but not after implementation of hepatitis C virus screening. LIMITATION: Observational study design, underascertainment of the outcome, and possible insufficient statistical power. CONCLUSION: The data provide no evidence for the transmission of neurodegenerative diseases and suggest that if transmission does occur, it is rare. PRIMARY FUNDING SOURCE: Swedish Research Council, Swedish Heart-Lung Foundation, Swedish Society for Medical Research, and Danish Council for Independent Research.

Snus use, smoking and survival among prostate cancer patients.

Smoking is associated with prostate cancer mortality. The Scandinavian smokeless tobacco product snus is a source of nicotine but not the combustion products of smoke and has not been studied with respect to prostate cancer survival. The study is nested among 9,582 men with incident prostate cancer within a prospective cohort of 336,381 Swedish construction workers. Information on tobacco use was collected at study entry between 1971 and 1992, and categorized into (i) never users of any tobacco, (ii) exclusive snus: ever users of snus only, (iii) exclusive smokers: ever smokers (cigarette, cigar and/or pipe) only and (iv) ever users of both snus and smoking. Hazard ratios for prostate cancer-specific and total mortality for smoking and snus use based on Cox proportional hazards models adjusted for age, calendar period at diagnosis and body mass index at baseline. During 36 years of follow-up, 4,758 patients died-2,489 due to prostate cancer. Compared to never users of tobacco, exclusive smokers were at increased risk of prostate cancer mortality (HR 1.15, 95% CI: 1.05-1.27) and total mortality (HR 1.17, 95% CI: 1.09-1.26). Exclusive snus users also had increased risks for prostate cancer mortality (HR 1.24, 95% CI: 1.03-1.49) and total mortality (HR 1.19, 95% CI: 1.04-1.37). Among men diagnosed with nonmetastatic disease, the HR for prostate cancer death among exclusive snus users was 3.17 (95% CI: 1.66-6.06). The study is limited by a single assessment of tobacco use prior to diagnosis. Snus use was associated with increased risks of prostate cancer and total mortality among prostate cancer patients. This suggests that tobacco-related components such as nicotine or tobacco-specific carcinogens may promote cancer progression independent of tobacco's combustion products.

Blood donation and risk of polycythemia vera.

BACKGROUND: It has been suggested that blood donors could have an increased risk of polycythemia vera (PV). However, no study has assessed whether frequent donors have a higher PV risk than less frequent donors. STUDY DESIGN AND METHODS: From the Scandinavian Donations and Transfusions (SCANDAT2) database, we established a cohort of blood donors who had donated whole blood at least once between 1980 and 2012. Within this cohort we first assessed the risk of PV, comparing the donors to the general population using standardized incidence ratios (SIRs) with corresponding 95% confidence intervals (CIs). To assess the association between frequency of blood donation and risk of PV we then conducted a case-control study nested within the cohort, where we compared prior donation activity among donors who were diagnosed with PV and matched controls. Here odds ratios (ORs) were used as measures of relative risk comparing donors with different donation frequency. RESULTS: Among 1.4 million donors in the cohort a total of 271 donors developed PV, yielding a SIR of 1.00 (95% CI, 0.89-1.13) compared to the general population. The nested case-control study showed no association between donation frequency and risk of PV. The OR of PV comparing donors who had made at least 33 donations in the period from 3 to 22 years before diagnosis of the case, to donors with one to eight donations in the same period was 1.01 (95% CI, 0.51-1.97). CONCLUSIONS: We find no evidence of excess risk of PV among blood donors or of an association between donation frequency and PV risk.

A prospective cohort study of the combined effects of physical activity and anthropometric measures on the risk of post-menopausal breast cancer.

Although keeping a healthy weight and being physically active are among the few modifiable risk factors for post-menopausal breast cancer, the possible interaction between these two risk factors remains to be established. We analyzed prospectively a cohort of 19,196 women who provided detailed self-report on anthropometric measures, physical activity and possible confounders at enrollment in 1997. We achieved complete follow-up through 2010 and ascertained 609 incident cases of post-menopausal invasive breast cancer. We calculated metabolic energy turnover (MET h/day) per day and fitted Cox proportional hazards models to estimate hazard ratios (HRs) with 95 % confidence intervals (CIs). The incidence of post-menopausal breast cancer among obese women (BMI ≥ 30 kg/m(2)) was 58 % higher (HR 1.58, CI 1.16-2.16) than in women of normal weight (18.5 ≤ BMI < 25). Women in the lowest tertile of total physical activity (< 31.2 MET h/day) had 40 % higher incidence of post-menopausal breast cancer (HR 1.40, CI 1.11-1.75) than those in the highest tertile (≥ 38.2 MET h/day). The excess incidence linked to these two factors seemed to combine in an approximately additive manner; the incidence among the most obese and sedentary women was doubled (HR 2.07, CI 1.31-3.25) compared with the most physically active women with normal weight. No heterogeneity of the physical activity-linked risk ratios across strata of BMI was detected (p value for interaction = 0.98). This prospective study revealed dose-dependent, homogenous inverse associations between post-menopausal breast cancer incidence and physical activity across all strata of BMI, and between post-menopausal breast cancer incidence and BMI across all strata of physical activity, with no evidence of additive or multiplicative interaction between the two, suggesting independent effects.

Cigarette- and snus-modified association between unprotected exposure to noise from hunting rifle caliber weapons and high frequency hearing loss. A cross-sectional study among swedish hunters.

AIM: To investigate in this cross-sectional study among Swedish hunters if tobacco use modifies the previously observed association, expressed as prevalence ratio (PR), between unprotected exposure to impulse noise from hunting rifle caliber (HRC) weapons and high-frequency hearing impairment (HFHI). SETTINGS AND DESIGN: A nationwide cross-sectional epidemiologic study was conducted among Swedish sport hunters in 2012. MATERIALS AND METHODS: The study was Internet-based and consisted of a questionnaire and an Internet-based audiometry test. RESULTS: In all, 202 hunters completed a questionnaire regarding the hearing test. Associations were modeled using Poisson regression. Current, daily use of tobacco was reported by 61 hunters (19 used cigarettes, 47 moist snuff, and 5 both). Tobacco users tended to be younger, fire more shots with HRC weapons, and report more hunting days. Their adjusted PR (1-6 unprotected HRC shots versus 0) was 3.2 (1.4-6.7), P < 0.01. Among the nonusers of tobacco, the corresponding PR was 1.3 (0.9-1.8), P = 0.18. P value for the interaction was 0.01. The importance of ear protection could not be quantified among hunters with HRC weapons because our data suggested that the HFHI outcome had led to changes in the use of such protection. Among hunters using weapons with less sound energy, however, no or sporadic use of hearing protection was linked to a 60% higher prevalence of HFHI, relative to habitual use. CONCLUSION: Tobacco use modifies the association between exposure to unprotected impulse noise from HRC weapons and the probability of having HFHI among susceptible hunters. The mechanisms remain to be clarified, but because the effect modification was apparent also among the users of smokeless tobacco, combustion products may not be critical for this effect.

Increase in the Prevalence of Atrophic Gastritis Among Adults Age 35 to 44 Years Old in Northern Sweden Between 1990 and 2009.

BACKGROUND & AIMS: Atrophic corpus gastritis (ACG) is believed to be an early precursor of gastric adenocarcinoma. We aimed to investigate trends of ACG in Northern Sweden, from 1990 through 2009, and to identify possible risk factors. METHODS: We randomly selected serum samples collected from 5284 participants in 1990, 1994, 1999, 2004, and 2009, as part of the population-based, cross-sectional Northern Sweden Multinational Monitoring of Trends and Determinants in Cardiovascular Disease study (ages, 35-64 y). Information was collected on sociodemographic, anthropometric, lifestyle, and medical factors using questionnaires. Serum samples were analyzed for levels of pepsinogen I to identify participants with functional ACG; data from participants with ACG were compared with those from frequency-matched individuals without ACG (controls). Blood samples were analyzed for antibodies against Helicobacter pylori and Cag pathogenicity island protein A. Associations were estimated with unconditional logistic regression models. RESULTS: Overall, 305 subjects tested positive for functional ACG, based on their level of pepsinogen I. The prevalence of ACG in participants age 55 to 64 years old decreased from 124 per 1000 to 49 per 1000 individuals between 1990 and 2009. However, the prevalence of ACG increased from 22 per 1000 to 64 per 1000 individuals among participants age 35 to 44 years old during this time period. Cag pathogenicity island protein A seropositivity was associated with risk for ACG (odds ratio, 2.29; 95% confidence interval, 1.69-3.12). Other risk factors included diabetes, low level of education, and high body mass index. The association between body mass index and ACG was confined to individuals age 35 to 44 years old; in this group, overweight and obesity were associated with a 2.8-fold and a 4.7-fold increased risk of ACG, respectively. CONCLUSIONS: Among residents of Northern Sweden, the prevalence of ACG increased from 1990 through 2009, specifically among adults age 35 to 44 years old. The stabilizing seroprevalence of H pylori and the increasing prevalence of overweight and obesity might contribute to this unexpected trend. Studies are needed to determine whether these changes have affected the incidence of gastric cancer.

Blood donation and blood donor mortality after adjustment for a healthy donor effect.

BACKGROUND: Studies have repeatedly demonstrated that blood donors experience lower mortality than the general population. While this may suggest a beneficial effect of blood donation, it may also reflect the selection of healthy persons into the donor population. To overcome this bias, we investigated the relation between blood donation frequency and mortality within a large cohort of blood donors. In addition, our analyses also took into consideration the effects of presumed health differences linked to donation behavior. STUDY DESIGN AND METHODS: Using the Scandinavian Donation and Transfusion database (SCANDAT), we assessed the association between annual number of donations in 5-year windows and donor mortality by means of Poisson regression analysis. The analyses included adjustment for demographic characteristics and for an internal healthy donor effect, estimated among elderly donors exempted from continued donation because of age criteria. RESULTS: Statistical analyses included 1,182,495 donors of whom 15,401 died during 9,526,627 person-years of follow-up. Analyses adjusted only for demographic characteristics showed a 18.6% reduction in mortality per additional annual donation (95% confidence interval [CI], 16.8%-20.4%). After additional adjustment for the internal healthy donor effect, each additional annual donation was associated with a 7.5% decreased mortality risk 7.5% (95% CI, 5.7%-9.4%). CONCLUSION: We observed an inverse relationship between donation frequency and mortality. The magnitude of the association was reduced after adjustment for an estimate of self-selection in the donor population. Our observations indicate that repeated blood donation is not associated with premature death, but cannot be interpreted as conclusive evidence of a beneficial health effect.

The new Scandinavian Donations and Transfusions database (SCANDAT2): a blood safety resource with added versatility.

BACKGROUND: Risks of transfusion-transmitted disease are currently at a record low in the developed world. Still, available methods for blood surveillance might not be sufficient to detect transmission of diseases with unknown etiologies or with very long incubation periods. STUDY DESIGN AND METHODS: We have previously created the anonymized Scandinavian Donations and Transfusions (SCANDAT) database, containing data on blood donors, blood transfusions, and transfused patients, with complete follow-up of donors and patients for a range of health outcomes. Here we describe the re-creation of SCANDAT with updated, identifiable data. We collected computerized data on blood donations and transfusions from blood banks covering all of Sweden and Denmark. After data cleaning, two structurally identical databases were created and the entire database was linked with nationwide health outcomes registers to attain complete follow-up for up to 47 years regarding hospital care, cancer, and death. RESULTS: After removal of erroneous records, the database contained 25,523,334 donation records, 21,318,794 transfusion records, and 3,692,653 unique persons with valid identification, presently followed over 40 million person-years, with possibility for future extension. Data quality is generally high with 96% of all transfusions being traceable to their respective donation(s) and a very high (>97%) concordance with official statistics on annual number of blood donations and transfusions. CONCLUSIONS: It is possible to create a binational, nationwide database with almost 50 years of follow-up of blood donors and transfused patients for a range of health outcomes. We aim to use this database for further studies of donor health, transfusion-associated risks, and transfusion-transmitted disease.

Physical activity and body mass index as predictors of prostate cancer risk.

PURPOSE: Physical activity and body mass index (BMI) are involved in prostate cancer etiology; possible biologic mechanisms include their effects on hormonal levels. Our aim was to investigate the relationship between physical activity, obesity, and prostate cancer. METHODS: We followed a cohort of 13,109 Swedish men for 13 years and investigated the association of self-reported physical activity and BMI at baseline with prostate cancer incidence. We further analyzed whether BMI could modulate effects of physical activity. Occupational, recreational, and total physical activity were analyzed in relation to overall, localized, and advanced prostate cancer. RESULTS: During the study follow-up, we observed a total of 904 cases of prostate cancer (429 localized, 407 advanced, and 68 unclassified). High levels of occupational physical activity were associated with a nonsignificantly decreased risk of overall (HR 0.81, 95 % CI 0.61-1.07), localized (HR 0.75, 95 % CI 0.51-1.12), and advanced (HR 0.85, 95 % CI 0.55-1.31) prostate cancer. We found no association between high BMI and risk of prostate cancer incidence: We observed, however, a significant interaction between BMI and leisure physical activity. CONCLUSION: No association was confirmed between total physical activity and localized or advanced prostate cancer. The highest, relative to the lowest, level of occupational physical activity tended to be linked to a lower risk of prostate cancer, with a suggested dose-response relationship. We found no association between high BMI and risk of prostate cancer incidence; however, our analyses suggested an interaction between BMI and physical activity during recreational time that merits further investigation in future studies.

Shooting history and presence of high-frequency hearing impairment in swedish hunters: A cross-sectional internet-based observational study.

The aim of this cross-sectional study among Swedish hunters was to examine the association between shooting history and presence of high-frequency hearing impairment (HFHI). All hunters registered with an e-mail address in the membership roster of the Swedish Hunters' Association were invited via e-mail to a secure website with a questionnaire and an Internet-based audiometry test. Associations, expressed as prevalence ratio (PR), were multivariately modelled using Poisson regression. The questionnaire was answered by 1771 hunters (age 11-91 years), and 202 of them also completed the audiometry test. Subjective severe hearing loss was reported by 195/1771 (11%), while 23/202 (11%) exhibited HFHI upon testing with Internet-based audiometry. As many as 328/1771 (19%) had never used hearing protection during hunting. In the preceding 5 years, 785/1771 (45%), had fired >6 unprotected gunshots with hunting rifle calibers. The adjusted PR of HFHI when reporting 1-6 such shots, relative to 0, was 1.5 [95% confidence interval (CI) 1.1-2.1; P = 0.02]. We could not verify any excessive HFHI prevalence among 89 hunters reporting unprotected exposure to such gunshot noise >6 times. Nor did the total number of reported rifle shots seem to matter. These findings support the notion of a wide variation in individual susceptibility to impulse noise; that significant sound energy, corresponding to unprotected noise from hunting rifle calibers, seems to be required; that susceptible individuals may sustain irreversible damage to the inner ear from just one or a few shots; and that use of hearing protection should be encouraged from the first shot with such weapons.

A CagA-independent cluster of antigens related to the risk of noncardia gastric cancer: associations between Helicobacter pylori antibodies and gastric adenocarcinoma explored by multiplex serology.

Because of the differences in bacterial epitopes and host characteristics, infections with Helicobacter pylori (H. pylori) induce different immune responses. We explored the possibility that certain antibody response patterns are more closely linked to gastric adenocarcinoma (GAC) than others. In a Swedish population-based case-control study, serum samples were obtained from 268 cases and 222 controls, aged 40-79 years and frequency-matched according to age and sex. We measured antibodies against 17 H. pylori proteins using multiplex serology. Associations were estimated with multivariably adjusted logistic regression models, using odds ratio (OR) with 95% confidence interval (CI) as measures of relative risk. Associations were essentially confined to non-cardia GAC but did not differ significantly between intestinal and diffuse subtypes. Point estimates for all antibodies were above unity, 15 significant with top three being CagA (OR = 9.2), GroEL (6.6), HyuA (3.6). ORs were substantially attenuated in individuals with chronic atrophic gastritis. Principal component analysis identified two significant factors: a CagA-dominant factor (antibodies against CagA, VacA and Omp as prominent markers), and a non-CagA factor (antibodies against NapA and Catalase as prominent markers). Both factors showed dose-dependent associations with non-cardia GAC risk (CagA-dominant factor, highest vs. lowest quartiles, OR = 16.2 [95% CI 4.8-54.9]; non-CagA factor OR = 5.3 [95% CI 2.1-13.3]). Overall, our results confirm that serum antibodies against different H. pylori proteins are associated with the presence of non-cardia GAC. Although strongest association is detected by antibodies against CagA and covarying proteins, a pattern of antibodies unrelated to CagA is also significantly linked to the risk of non-cardia GAC.

Gastroesophageal reflux does not alter effects of body mass index on risk of esophageal adenocarcinoma.

BACKGROUND & AIMS: A history of high body mass index (BMI) is associated strongly with a risk of esophageal adenocarcinoma (EAC). We investigated whether gastroesophageal reflux is involved in this association. METHODS: We analyzed data from a population-based Swedish nationwide study of patients with a new diagnosis of EAC (n = 189) or gastroesophageal junction adenocarcinoma (n = 262), and matched controls (n = 816), from 1995 through 1997. Our analysis included data on BMI 20 years before study inclusion; maximum adult BMI; frequency, severity, and duration of gastroesophageal reflux symptoms; tumor features; and covariates (sex, age, smoking, alcohol, fruit and vegetable intake, and socioeconomic status). We conducted stratified analyses and synergy tests, adjusting for covariates. RESULTS: Odds ratios (ORs) for EAC among subjects with a BMI of 25 or higher 20 years before inclusion, compared with those with a BMI less than 25, did not differ significantly, without or with adjustment for gastroesophageal reflux frequency (OR, 3.1; 95% confidence interval [CI], 2.2-4.4; and OR, 3.3; 95% CI, 2.2-4.8, respectively), severity (OR, 3.3; 95% CI, 2.2-4.8), or duration (OR, 3.2; 95% CI, 2.2-4.7). However, there were interactions between BMI and categories of gastroesophageal reflux. BMI appeared to have the largest effect on gastroesophageal reflux frequency (synergy index, 8.9; 95% CI, 2.3-34.1 for maximum BMI; and gastroesophageal reflux >3 times/wk). CONCLUSIONS: Based on a population-based study, the association between BMI and EAC does not appear to be affected by symptomatic gastroesophageal reflux, although there appears to be synergy between BMI and reflux.

Associations of hand-washing frequency with incidence of acute respiratory tract infection and influenza-like illness in adults: a population-based study in Sweden.

BACKGROUND: Frequent hand-washing is standard advice for avoidance of respiratory tract infections, but the evidence for a preventive effect in a general community setting is sparse. We therefore set out to quantify, in a population-based adult general population cohort, the possible protection against acute respiratory tract infections (ARIs) conferred by a person's self-perceived hand-washing frequency. METHODS: During the pandemic influenza season from September 2009 through May 2010, a cohort of 4365 adult residents of Stockholm County, Sweden, reported respiratory illnesses in real-time. A questionnaire about typical contact and hand-washing behaviour was administered at the end of the period (response rate 70%). RESULTS: There was no significant decrease in ARI rates among adults with increased daily hand-washing frequency: Compared to 2-4 times/day, 5-9 times was associated with an adjusted ARI rate ratio (RR) of 1.08 (95% confidence interval [CI] 0.87-1.33), 10-19 times with RR = 1.22 (CI 0.97-1.53), and ≥20 times with RR = 1.03 (CI 0.81-1.32). A similar lack of effect was seen for influenza-like illness, and in all investigated subgroups. We found no clear effect modification by contact behaviour. Health care workers exhibited rate ratio point estimates below unity, but no dose-risk trend. CONCLUSIONS: Our results suggest that increases in what adult laymen perceive as being adequate hand-washing may not significantly reduce the risk of ARIs. This might have implications for the design of public health campaigns in the face of threatening outbreaks of respiratory infections. However, the generalizability of our results to non-pandemic circumstances should be further explored.

A global assessment of the oesophageal adenocarcinoma epidemic.

OBJECTIVE: About 20 years ago, the scientific community was first alerted to an enigmatic increase of oesophageal adenocarcinomas in the UK and USA. Subsequently, a virtual epidemic-still unexplained-was confirmed in several western countries. Detailed descriptive data might provide clues to its causes. DESIGN: We collected data on incident cases of oesophageal adenocarcinoma from population-based cancer registries in Australia, Europe, North America and Asia. We calculated age-standardised incidence rates and fitted log-linear Poisson models to assess annual rate of increase and to disentangle age-period-cohort effects, linear spine models to estimate rate of increase since 1985, and Joinpoint models to identify possible inflection points. RESULTS: With considerable between-registry variation in magnitude and timing, we found a consistent dramatic increase in incidence with an observed or estimated start between 1960 and 1990. The average annual increase ranged from 3.5% in Scotland to 8.1% in Hawaii with similar proportional increase among men and women in most registries and a maintained three to sixfold higher incidence among men. Generally, calendar period was a more important determinant of incidence trends than birth cohort. Where possible to conduct, Joinpoint analyses indicated that the onset of the epidemic varied considerably even between neighbouring countries. CONCLUSIONS: Given the preponderant period effect and the abrupt onset observed or inferred in most populations, the epidemic appears to be caused by some exposure that was first introduced around 1950. At least 30 years' variation in estimated time of onset opens prospects for hypothesis-generating ecological analyses.

Tobacco use and cancer survival: a cohort study of 40,230 Swedish male construction workers with incident cancer.

On theoretical grounds, nicotine has been implicated as a modifier of cancer progression. We investigated possible associations of smoking or use of Scandinavian moist snuff (snus) with survival after cancer among Swedish male construction workers. Snus use is associated with substantial exposure to nicotine but not to the combustion products in smoke. Among 336,381 workers with detailed information on tobacco use in 1971-1992, we observed 40,230 incident cancers. Complete follow-up through 2007 was accomplished through linkage to population and health registers. Hazard ratios (HRs) and 95% confidence intervals (CIs) for death from any cause, cancer-specific death and death from other causes were derived from Cox proportional hazards regression models adjusted for age at diagnosis, body mass index at study entry and period of diagnosis. Never users of any tobacco served as reference. Increased risks of cancer-specific death were observed both among exclusive smokers (HR(all cancer) 1.15, 95% CI: 1.10-1.21) and never-smoking snus users (1.15, 95% CI: 1.05-1.26). As regards deaths due to other causes, exclusive smokers had higher relative risks than exclusive snus users (p = 0.03). A history of tobacco use, even exclusive use of the seemingly benign snus, is associated with moderately increased cancer-specific mortality. Although nicotine might play a role, the mechanisms warrant further investigation.

Alcohol intake and risk of oesophageal adenocarcinoma: a pooled analysis from the BEACON Consortium.

BACKGROUND AND AIMS: Alcohol intake is a strong and well established risk factor for oesophageal squamous cell carcinoma (OSCC), but the association with oesophageal adenocarcinoma (OA) or adjacent tumours of the oesophagogastric junction (OGJA), remains unclear. Therefore, the association of alcohol intake with OSCC, OA, and OGJA was determined in nine case-control studies and two cohort studies of the Barrett's Esophagus and Esophageal Adenocarcinoma Consortium (BEACON). MATERIALS AND METHODS: Information was collected on alcohol intake, age, sex, education, body mass index, gastro-oesophageal reflux, and tobacco smoking from each study. Along with 10,854 controls, 1821 OA, and 1837 OGJA, seven studies also collected OSCC cases (n=1016). Study specific ORs and 95% CIs were calculated from multivariate adjusted logistic regression models for alcohol intake in categories compared to non-drinkers. Summary risk estimates were obtained by random effects models. Results No increase was observed in the risk of OA or OGJA for increasing levels of any of the alcohol intake measures examined. ORs for the highest frequency category (≥ 7 drinks per day) were 0.97 (95% CI 0.68 to 1.36) for OA and 0.77 (95% CI = 0.54 to 1.10) for OGJA. Suggestive findings linked moderate intake (eg, 0.5 to <1 drink per day) to decreased risk of OA (OR 0.63, 95% CI 0.41 to 0.99) and OGJA (OR 0.78, 95% CI 0.62 to 0.99). In contrast, alcohol intake was strongly associated with increased risk of OSCC (OR for ≥ 7 drinks per day 9.62, 95% CI 4.26 to 21.71). CONCLUSIONS: In contrast to OSCC, higher alcohol consumption was not associated with increased risk of either OA or OGJA. The apparent inverse association observed with moderate alcohol intake should be evaluated in future prospective studies.

Smoking, snus use and risk of right- and left-sided colon, rectal and anal cancer: a 37-year follow-up study.

Although some authorities consider smoking to be an established risk factor for colorectal cancer, the international literature is not entirely consistent. Further, only 1 study has addressed the association with smokeless tobacco and none with Scandinavian moist snuff (snus). This retrospective cohort study included 336,381 male Swedish construction workers with detailed information on tobacco use at cohort entry in 1971-1992. Complete follow-up through 2007 was accomplished by means of linkage to population and health registers. Hazard ratios (HRs) and 95% confidence intervals (CIs) derived from Cox proportional hazards regression models estimated relative risks, adjusted for age and body mass index. Subjects who were never-users of any tobacco served as reference. After up to 37 years of follow-up, pure smoking was associated with a marginally increased risk of colon cancer (HR 1.08, 95% CI 0.99-1.19), a modestly elevated risk of rectal cancer (HR 1.16, 95% CI 1.04-1.30) and a substantial excess risk of anal cancer (HR 2.41, 95% CI 1.06-5.48). Snus use was not significantly associated with an increased risk of colorectal or anal cancer, although the point estimate for colon cancer was similar to that observed among smokers. Swedish data provide meager support for the association between tobacco use and colorectal cancer. A general tendency among Swedish men to quit smoking in recent decades might have attenuated true associations. A link between smoking and anal cancer was confirmed.