The health impact of smokeless tobacco products: a systematic review.

INTRODUCTION: The objective was to systematically review studies on health outcomes from smokeless tobacco (SLT) products. METHODS: We analysed published literature on the health outcomes from SLT use between 01/01/2015 to 01/02/2020, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol using PubMed, Embase, Scopus, and Google Scholar. RESULTS: Of 53 studies included, six were global, 32 from Asia, Middle East and Africa (AMEA), nine from USA and six from Europe. 'Poor'-rated studies predominated (23;43%), in particular, for global (4;66%) and AMEA (16;50%). Health outcomes differed between SLT-products and regions; those in AMEA were associated with higher mortality (overall, cancer, Coronary heart disease (CHD), respiratory but not cardiovascular disease (CVD)), and morbidity (CVD, oral and head and neck cancers), with odds ratios up to 38.7. European studies showed no excess mortality (overall, CVD, from cancers) or morbidity (ischemic heart disease (IHD), stroke, oral, head and neck, pancreatic or colon cancers) from several meta-analyses; single studies reported elevated risk of rectal cancer and respiratory disorders. Pooled study data showed protection against developing Parkinson's disease. US studies showed mixed results for mortality (raised overall, CHD, cancer and smoking-related cancer mortality; no excess risk of respiratory or CVD mortality). Morbidity outcomes were also mixed, with some evidence of increased IHD, stroke and cancer risk (oral, head and neck). No studies reported on switching from cigarettes to SLT-products. CONCLUSION: Our review demonstrates stark differences between different SLT-products in different regions, ranging from zero harm from European snus to greatly increased health risks in AMEA. The literature on the safety profile for SLT-products for harm reduction is incomplete and potentially misinforming policy and regulation.

Midwakh/dokha tobacco use in the Middle East: much to learn.

Many alternative tobacco products (ATPs), such as hookahs, have grown in popularity and use beyond their locale of origin and are therefore becoming a significant global public health concern. This article provides an overview of an under-reported and understudied ATP, dokha, which is smoked in a midwakh pipe. It describes the state of tobacco control in the Arabian Gulf region where midwakh smoking appears to be most common, the history of midwakh and dokha use, and what is known about midwakh smoking from the published literature. On the basis of the stark lack of data on midwakh use, we suggest priority areas to focus future research. Preliminary data and observations from health providers and the public health sector suggest that midwakh smoking may pose challenges to the tobacco control efforts in the Arabian Gulf region. If it is emerging as a new ATP outside this region, there could be a significant impact on tobacco control strategies globally.

Ischaemic stroke subtypes in children and adults.

Ischaemic stroke subtypes in children and adults were compared to determine the similarity in aetiologies. Thirty-six children (22 females, 14 males; median age 5 years 7 months, range 6 weeks to 15 years 10 months) and 50 adults (35 males, 15 females; median age 44 years, range 17 years 2 months to 49 years 11 months) who had presented with ischaemic stroke between 1995 and 2000, were categorized using a modified version of the Trial of Org 10172 in Acute Stroke Therapy (TOAST) classification. Proportions of patients in the subtypes of the TOAST classification system were significantly different in the two groups (chi2 test, p<0.01). The first three subtypes (large artery atherosclerosis, cardioembolic, and small vessel disease) accounted for the majority of adult strokes (27 of 50). In contrast, only three of 36 children were accounted for within these three subtypes. The majority of children (29 of 36) were classified within the 'other determined aetiology' subtype. Aetiology was undetermined in 12 of 50 adults compared with three of 36 children. Causes of ischaemic stroke in children and adults are distinct. A classification system for ischaemic stroke in children would be useful for collaborative studies.

Incidence and case fatality rates of stroke subtypes in a multiethnic population: the South London Stroke Register.

OBJECTIVE: To identify sociodemographic differences in the incidence of the subtypes of first ever stroke in a multiethnic population. METHODS: A prospective community stroke register (1995-8) was developed using multiple notification sources and pathological and clinical classifications of stroke. Standardisation of rates was to European and World populations and adjusted for age, sex and socioeconomic status in multivariate analyses. A multiethnic population of 234 533 in south London, of whom 21% are black was studied. RESULTS: A total of 1254 cases were registered. The average age of stroke was 71.7 years with black patients being 11.3 years younger than white patients (p<0.0001). The incidence rate/1000 population was 1.33 (crude) (95% CI 1.26 to 1.41), 1.28 (European adjusted) (95% CI 1.2 to 1.35) with a 2.18 (95% CI 1.86 to 2.56) (p<0.0001) age and sex adjusted incidence rate ratio in the black population. Radiological diagnosis was confirmatory in 1107 (88.3%) with 862 (68.7%) infarction, 168 (13.4%) primary intracerebral haemorrhage, and 77 (6.2%) subarachnoid haemorrhage. Of the cerebral infarction cases 189 (21.9%) were total anterior circulatory, 250 (29%) partial anterior, 141 (16.4%) posterior (POCI) and 282 (32.7%) lacunar infarcts. The black group had a significantly higher incidence of all subtypes of stroke except for POCI and unclassified strokes. The incidence rate ratio (IRR) for men compared with women was 1.34 (95% confidence interval (95% CI) 1.19 to 1.50; p<0.001). The IRR for manual versus non-manual occupations in those aged 35-64 years was 1.64 (95%CI 1.22 to 2.23; p<0.0001). There was a borderline significant increase in adjusted survival at 6 months in the black group 95% (CI 0.61 to 1.03, p=0.078) with a hazard ratio of 0.79 after adjustment and stratification. CONCLUSIONS: Although the black population is at increased risk of stroke and most subtypes of stroke, this is not translated into significant differences in survival. Hence black/white differences in mortality are mainly driven by incidence of stroke. There are striking demographic inequalities in the risk of stroke in this multiethnic inner city population that need to be tackled through interagency working. Although the reasons for the increased risk in the black population are unclear, demographic factors such as socioeconomic status do seem to play a significant independent part.

The inter- and intraobserver reliabilities of a new classification system for ischaemic stroke: the South London Stroke Register.

OBJECTIVES: This study aims to determine the inter- and intraobserver reliabilities of an aetiological classification devised as part of a community-based stroke register. METHODS: Patients with first-ever acute ischaemic stroke were clinically assessed and received investigation according to a set protocol. Results of the clinical assessment and investigations were used to determine an aetiological stroke subtype for each patient by observer 1. Aetiological subtypes consisted of extracranial large artery atherosclerosis (LAAec), intracranial large artery atherosclerosis (LAAic), high-risk cardioembolism (CH), medium-risk cardioembolism (CM), small vessel occlusion (SVO), other aetiology (OTH), no aetiology identified (NA) and multiple probable or multiple possible aetiology (MPA). The same data were distributed to a further four observers along with the criteria for the classification system. Two of the observers were retested on the same patients after of period of 8 weeks. Inter- and intraobserver agreement was determined using the kappa statistic, which gives the chance-adjusted percentage agreement. RESULTS: Forty-five consecutive patients were included. The overall kappa statistic for ischaemic stroke was 0.91 indicating excellent agreement. Kappa statistics were highest for the more frequent subtypes of SVO (0.97) and CH (0.97). Substantially high kappa statistics were also obtained for the less-frequent categories of LAAec (0.91), CM (0.84), NA (0.89) and MPA (0.87). A low kappa statistic was obtained for the category OTH (0.16), which had a low frequency of reporting, indicating poor agreement. The kappa statistic for probable categories was higher than the kappa statistic for all stroke subtypes at 0.96. Intraobserver agreement between first and second assignments of subtype diagnoses for both observers reached excellent agreement with kappa statistics of 0.83 and 0.85. CONCLUSION: The aetiological classification system, designed for use in the investigation of the epidemiology, stroke subtype and their relation to the natural history of stroke in a multiethnic inner city population, allows high inter- and intrarater agreements of subtype diagnosis.

Cerebrovascular risk factors and stroke subtypes: differences between ethnic groups.

BACKGROUND AND PURPOSE: The excess risk of stroke seen in the black population has not been explained by differences in age, sex, and social class, although differences in the frequency of cerebrovascular risk factors may be partly responsible. Data on risk factor profiles for the UK black stroke population are sparse. Previous studies have contrasted the association of cerebrovascular risk factors between hemorrhagic and ischemic stroke and between etiologic subtypes of infarct. The relationship of cerebrovascular risk factors to clinical classifications of stroke, however, has been little examined. The aim of this study was to establish the frequency of cerebrovascular risk factors in patients with first-ever strokes in the South London, UK, population and to examine the relationship of these risk factors to both ethnicity and Bamford stroke subtype. METHODS: The study included 1254 first-ever stroke patients registered in the South London Community Stroke Register between 1995 and 1998; 995 patients (79.3%) were white, 203 (16.2%) were black, 52 (4.1%) were of other ethnic origin, and 4 (0. 3%) were of unknown ethnic origin. RESULTS: In multivariate analysis, increasing age (P:<0.001) and previous cerebrovascular disease (P:=0.007) were independently associated with infarct rather than hemorrhage. Atrial fibrillation was associated with all nonlacunar (P:=0.02), total anterior circulation (P:=0.007), and partial anterior circulation infarcts (P:=0.02) compared with the lacunar group. All other risk factors were similar between infarct subtypes. Risk factors for hemorrhage subtypes were similar in multivariate analysis; increasing age was the only factor associated with primary intracerebral hemorrhage over subarachnoid hemorrhage (P:<0.001). The black stroke population suffered significantly less atrial fibrillation (P:=0.001) and engaged in less alcohol excess (P:<0. 001) and were less likely to have ever smoked (P:<0.001). Hypertension (P:<0.001) and diabetes mellitus (P:<0.001) were more prevalent in the black population. CONCLUSIONS: Physiological cerebrovascular risk factors for the UK black population are similar to those of the US black population, but behavioral risk factors differ. Risk factors differ between ethnic groups in the United Kingdom, and future measures for secondary prevention should take this into consideration. Bamford clinical subtypes bear little association with cerebrovascular risk factors. Other classification systems, such as those that classify stroke by etiology, may be more useful in explaining the excess risk of stroke and the scope for its prevention.

Effects of poststroke pyrexia on stroke outcome : a meta-analysis of studies in patients.

BACKGROUND AND PURPOSE: The effect of pyrexia on cerebral ischemia has been extensively studied in animals. In humans, however, such studies are small and the results conflicting. We undertook a meta-analysis using all such published studies on the effect of hyperthermia on stroke outcome. METHODS: Three databases were searched for all published studies that examined the relationship of raised temperature after stroke onset and eventual outcome. Combined probability values and odds ratios were obtained. A heterogeneity test was performed to ensure that the data were suitable for such an analysis. Morbidity and mortality were used as outcome measures. RESULTS: Nine studies were identified totaling 3790 patients, providing our study with 99% power to detect a 9% increase in morbidity and 84% power to detect a 1% increase in mortality for the pyrexial group. The combined odds ratio for mortality was 1.19 (95% CI, 0.99 to 1.43). A heterogeneity test was highly nonsignificant (P>0.05) for mortality, suggesting that the data were sufficiently similar to be meta-analyzed. Combined probability values were highly significant for both morbidity (P<0.0001) and mortality (P<0. 00000001). CONCLUSIONS: The results from this meta-analysis suggest that pyrexia after stroke onset is associated with a marked increase in morbidity and mortality. Measures should be taken to combat fever in the clinical setting to prevent stroke progression. The possible benefit of therapeutic hypothermia in the management of acute stroke should be further investigated.