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Attributable Fraction (attributable + fraction)
Kinds of Attributable Fraction Selected AbstractsAttributable fractions for partitioning risk and evaluating disease prevention: a practical guideTHE CLINICAL RESPIRATORY JOURNAL, Issue 2008Geir E. Eide Abstract Introduction:, The attributable fraction (AF) is used for quantifying the fraction of diseased ascribable to one or more exposures. The methodology and software for its estimation has undergone a considerable development during the last decades. Objectives:, To introduce methods for: (i) apportioning excess risk to multiple exposures, groups of exposures and subpopulations; (ii) graphical description; and (iii) survival data. Results:, Adjusted, sequential and average AFs are reasonable measures obtainable with standard software. The latter two both sum up to the combined AF for a set of exposures. The average AFs are independent of the exposures' ordering. For an ordered, preventive strategy, scaled sample space cubes illustrate the effects on the risk of disease from stepwise exposure removal. Pie charts illustrate the portions of the total risk ascribed to different exposures or risk-profiles. Attributable hazard fraction, AF before time t, and AF within study incorporate time to disease and interventions. Conclusions:, The practice of crude calculations of AFs in epidemiology should be abandoned. Further development of methods for AFs with survival data and possibly linking it to causal modelling is of interest. Please cite this paper as: Eide GE. Attributable fractions for partitioning risk and evaluating disease prevention: a practical guide. The Clinical Respiratory Journal 2008; 2: 92,103. [source] Identifying target groups for the prevention of anxiety disorders in the general populationACTA PSYCHIATRICA SCANDINAVICA, Issue 1 2010N. M. Batelaan Batelaan NM, Smit F, de Graaf R, van Balkom AJLM, Vollebergh WAM, Beekman ATF. Identifying target groups for the prevention of anxiety disorders in the general population. Objective:, To avert the public health consequences of anxiety disorders, prevention of their onset and recurrence is necessary. Recent studies have shown that prevention is effective. To maximize the health gain and minimize the effort, preventive strategies should focus on high-risk groups. Method:, Using data from a large prospective national survey, high-risk groups were selected for i) the prevention of first ever (n = 4437) and ii) either first-ever or recurrent incident anxiety disorders (n = 4886). Indices used were: exposure rate, odds ratio, population attributable fraction and number needed to be treated. Risk indicators included sociodemographic, psychological and illness-related factors. Results:, Recognition of a few patient characteristics enables efficient identification of high-risk groups: (subthreshold) panic attacks; an affective disorder; a history of depressed mood; a prior anxiety disorder; chronic somatic illnesses and low mastery. Conclusion:, Preventive efforts should be undertaken in the selected high-risk groups. [source] Cannabis and schizophrenia: model projections of the impact of the rise in cannabis use on historical and future trends in schizophrenia in England and WalesADDICTION, Issue 4 2007Matthew Hickman ABSTRACT Aims To estimate long-term trends in cannabis use and projections of schizophrenia assuming a causal relation between cannabis use and schizophrenia. Methods Trends in cannabis use were estimated from a national survey, 2003; and incidence of schizophrenia was derived from surveys in three English cities, 1997,99. A difference equation cohort model was fitted against estimates of schizophrenia incidence, trends in cannabis exposure and assumptions on association between cannabis and schizophrenia. The model projects trends in schizophrenia incidence, prevalence and attributable fraction of cannabis induced schizophrenia. Results Between 1970 and 2002 cannabis exposure increased: incidence by fourfold; period prevalence by 10-fold; and use among under 18-year-olds by 18-fold. In 1997,99 incidence and prevalence of schizophrenia were 17 per 100 000 and 0.63% among men and 7.3 per 100 000 and 0.23% among women, respectively. If cannabis use causes schizophrenia, earlier increases in cannabis use would lead to increases in overall schizophrenia incidence and prevalence of 29% and 12% among men between 1990 and 2010. By 2010 model projections which assume an association between schizophrenia and light and heavy users suggest that approximately one-quarter of new schizophrenia cases could be due to cannabis, whereas if the association is twofold and confined to heavy cannabis users, then approximately 10% of schizophrenia cases may be due to cannabis. Conclusions If cannabis use causes schizophrenia, and assuming other causes are unchanged, then relatively substantial increases in both prevalence and incidence of schizophrenia should be apparent by 2010. More accurate data on cannabis consumption and future monitoring of schizophrenia are critical. [source] Neonatal health care costs related to smoking during pregnancyHEALTH ECONOMICS, Issue 3 2002E. Kathleen Adams Abstract Research objective: Much of the work on estimating health care costs attributable to smoking has failed to capture the effects and related costs of smoking during pregnancy. The goal of this study is to use data on smoking behavior, birth outcomes and resource utilization to estimate neonatal costs attributable to maternal smoking during pregnancy. Study design: We use 1995 data from the Center for Disease Control's (CDC) Pregnancy Risk Assessment Monitoring System (PRAMS) database. The PRAMS collects representative samples of births from 13 states (Alabama, Alaska, California, Florida, Georgia, Indiana, Maine, Michigan, New York (excluding New York City), Oklahoma, South Carolina, Washington, and West Virginia), and the District of Columbia. The 1995 PRAMS sample is approximately 25 000. Multivariate analysis is used to estimate the relationship of smoking to probability of admission to an NICU and, separately, the length of stay for those admitted or not admitted to an NICU. Neonatal costs are predicted for infants ,as is' and ,as if' their mother did not smoke. The difference between these constitutes smoking attributable neonatal costs; this divided by total neonatal costs constitutes the smoking attributable fraction (SAF). We use data from the MarketScanÔ database of the MedStatÔ Corporation to attach average dollar amounts to NICU and non-NICU nursery nights and data from the 1997 birth certificates to extrapolate the SAFs and attributable expenses to all states. Principal findings: The analysis showed that maternal smoking increased the relative risk of admission to an NICU by almost 20%. For infants admitted to the NICU, maternal smoking increased length of stay while for non- NICU infants it appeared to lower it. Over all births, however, smoking increased infant length of stay by 1.1%. NICU infants cost $2496 per night while in the NICU and $1796 while in a regular nursery compared to only $748 for non-NICU infants. The combination of the increased NICU use, longer stays and higher costs result in a positive smoking attributable fraction (SAF) for neonatal costs. The SAF across all states is 2.2%. Across the states, the SAF varied from a low of 1.3% in Texas to a high of 4.6% in Indiana. Conclusions: These results further confirm the adverse effects of smoking. Among mothers who smoke, smoking adds over $700 in neonatal costs. The smoking attributable neonatal costs in the US represent almost $367 million in 1996 dollars; these costs vary from less than a million in smaller states to over $35 million in California. These costs are highly preventable since the adverse effects of maternal smoking occur in the short-run and can be avoided by even a temporary cessation of maternal smoking. These cost estimates can be used by managed care plans, state and local public health officials and others to evaluate alternative smoking cessation programs. Copyright © 2002 John Wiley & Sons, Ltd. [source] International study of wheezing in infants: risk factors in affluent and non-affluent countries during the first year of lifePEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 5 2010Luis Garcia-Marcos Garcia-Marcos L, Mallol J, Solé D, Brand PLP and EISL group. International study of wheezing in infants: risk factors in affluent and non-affluent countries during the first year of life. Pediatr Allergy Immunol 2010: 21: 878,888. © 2010 John Wiley & Sons A/S Risk factors for wheezing during the first year of life (a major cause of respiratory morbidity worldwide) are poorly known in non-affluent countries. We studied and compared risk factors in infants living in affluent and non-affluent areas of the world. A population-based study was carried out in random samples of infants from centres in Latin America (LA) and Europe (EU). Parents answered validated questionnaires referring to the first year of their infant's life during routine health visits. Wheezing was stratified into occasional (1,2 episodes, OW) and recurrent (3 + episodes, RW). Among the 28687 infants included, the most important independent risk factors for OW and RW (both in LA and in EU) were having a cold during the first 3 months of life [OR for RW 3.12 (2.60,3.78) and 3.15 (2.51,3.97); population attributable fraction (PAF) 25.0% and 23.7%]; and attending nursery school [OR for RW 2.50 (2.04,3.08) and 3.09 (2.04,4.67); PAF 7.4% and 20.3%]. Other risk factors were as follows: male gender, smoking during pregnancy, family history of asthma/rhinitis, and infant eczema. Breast feeding for >3 months protected from RW [OR 0.8 (0.71,0.89) in LA and 0.77 (0.63,0.93) in EU]. University studies of mother protected only in LA [OR for OW 0.85 (0.76,0.95) and for RW 0.80 (0.70,0.90)]. Although most risk factors for wheezing are common in LA and EU; their public health impact may be quite different. Avoiding nursery schools and smoking in pregnancy, breastfeeding babies >3 months, and improving mother's education would have a substantial impact in lowering its prevalence worldwide. [source] Population attributable fraction of smoking to low birth weight in JapanPEDIATRICS INTERNATIONAL, Issue 3 2004Toshiyuki Ojima AbstractBackground:,The purpose of this study is to quantify the population attributable fraction of active and passive smoking for low birth weight in Japan. Methods:,A population-based case-control study was conducted by mailing self-report questionnaires. The cases were all singleton low birth weight babies who were born between 1 January 1998 and 30 June 1999 in Tochigi prefecture, Japan. The controls were randomly selected from all singleton babies who were born during the same period as cases in the prefecture. Results:,The number of cases and controls were 286 and 404, respectively. Population attributable fractions of active smoking during and before pregnancy were 7.0% and 8.8%, respectively. Population attributable fraction of passive smoking at home was 15.6% and at the workplace was 1.1%. Combined population attributable fraction of both active and passive smoking was 17.3%. Conclusion:,Public education to eliminate passive smoking for pregnant women and smoking prevention in adolescence is very important in order to reduce the risk of low birth weight. [source] Hospital system costs of artificial infant feeding: estimates for the Australian Capital TerritoryAUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 6 2002Julie P. Smith Objective: To estimate the attributable ACT hospital system costs of treating selected infant and childhood illnesses having known associations with early weaning from human milk. Method: We identified relative risks of infant and childhood morbidity associated with exposure to artificial feeding in the early months of life vs breastfeeding from cohort studies cited by the American Academy of Pediatrics in 1997 as establishing the protective effect of breastfeeding. Data for ACT breastfeeding prevalence is assessed from a 1997 prospective population-based cohort study of 1,295 women. ACT Hospital Morbidity Data and DRG treatment costs were used to estimate the attributable fraction of costs of hospitalisation for gastrointestinal illness, respiratory illness and otitis media, eczema, and necrotising enterocolitis. Results: Although initiation rates were high (92%), less than one in 10 ACT infants are exclusively breastfed for the recommended six months, mainly due to supplementation or weaning on to formula within the first three months and the early introduction of solids by breastfeeding mothers. This study suggests the attributable hospitalisation costs of early weaning in the ACT are about $1 -2 million a year for the five illnesses. Conclusions and implications: Early weaning from breast milk is associated with significant hospital costs for treatment of gastrointestinal illness, respiratory illness and otitis media, eczema, and necrotising enterocolitis These costs are minimum estimates of the cost of early weaning as they exclude numerous other chronic or common illnesses and out-of-hospital health care costs. Higher rates of exclusive breastfeeding would reduce these costs. Interventions to protect and support breastfeeding are likely to be cost-effective for the public health system. [source] Assessing the validity of potential alcohol-related non-fatal injury indicatorsADDICTION, Issue 3 2008John Langley ABSTRACT Aim To assess critically the face validity of the World Health Organization's (WHO's) International Guide for Monitoring Alcohol Consumption and Related Harm (MACRH) for deriving indicators, for the purposes of developing non-fatal alcohol-related injury indicators in New Zealand. Design MACRH's five solutions for deriving indicators are: (i) use only alcohol-specific cases; (ii) identify subsets of events known to be highly alcohol-related; (iii) utilize control indicators that are rarely alcohol-related; (iv) estimate alcohol attributable fractions (AAFs) and adjust indicators accordingly; and (v) develop composite indicators. These were assessed in terms of their face validity with particular reference to New Zealand. Findings There are significant face validity issues with each of the five options. Solution 4 offers the greatest promise, provided that: (i) valid AAFs can be derived and they are updated regularly; and (ii) appropriate adjustment is made for extraneous influences on the estimates of alcohol-related harm. To date, the latter has not been carried out. Conclusions Most potential sources of data on alcohol-related harm are subject to extraneous influences, which vary over time and space. While the attempt by WHO to offer solutions to this problem is laudable, the solutions do not address the problem adequately. MACRH guidelines need to be revised to include criteria for a valid outcome indicator. [source] The burden of overweight and obesity-related ill health in the UKOBESITY REVIEWS, Issue 5 2007S. Allender Summary This paper reviews previous cost studies of overweight and obesity in the UK. It proposes a method for estimating the economic and health costs of overweight and obesity in the UK which could also be used in other countries. Costs of obesity studies were identified via a systematic search of electronic databases. Information from the WHO Burden of Disease Project was used to calculate the mortality and morbidity cost of overweight and obesity. Population attributable fractions for diseases attributable to overweight and obesity were applied to National Health Service (NHS) cost data to estimate direct financial costs. We estimate the direct cost of overweight and obesity to the NHS at £3.2 billion. Other estimates of the cost of obesity range between £480 million in 1998 and £1.1 billion in 2004 [Correction added after online publication 11 June 2007: ,of the cost of obesity' added after ,Other estimates']. There is wide variation in methods and estimates for the cost of overweight and obesity to the health systems of developed countries. The method presented here could be used to calculate the costs of overweight and obesity in other countries. Public health initiatives are required to address the increasing prevalence of overweight and obesity and reduce associated healthcare costs. [source] The burden of overweight and obesity in the Asia,Pacific regionOBESITY REVIEWS, Issue 3 2007Asia Pacific Cohort Studies Collaboration Summary The rise in the prevalence of overweight and obesity (body mass index ,25 kg m,2) is, in part, a negative consequence of the increasing economic developments of many lower- and middle-income countries in the Asia,Pacific region. To date, there has been no systematic quantification of the scale of the problem in countries of this region. From the most recent nationally representative estimates for the prevalence of overweight and obesity in 14 countries of the region, it is apparent that overweight and obesity is endemic in much of the region, prevalence ranging from less than 5% in India to 60% in Australia. Moreover, although the prevalence in China is a third of that in Australia, the increase in prevalence in China over the last 20 years was 400% compared with 20% in Australia. In addition, across various countries in the region, the population attributable fractions because of overweight and obesity ranged from 0.8% to 9.2% for coronary heart disease mortality, 0.2% to 2.9% for haemorrhagic stroke mortality, and 0.9% to 10.2% for ischaemic stroke mortality. These results indicate that consequences of overweight and obesity for health and the economy of many of these countries are likely to increase in coming years. [source] Population attributable fraction of smoking to low birth weight in JapanPEDIATRICS INTERNATIONAL, Issue 3 2004Toshiyuki Ojima AbstractBackground:,The purpose of this study is to quantify the population attributable fraction of active and passive smoking for low birth weight in Japan. Methods:,A population-based case-control study was conducted by mailing self-report questionnaires. The cases were all singleton low birth weight babies who were born between 1 January 1998 and 30 June 1999 in Tochigi prefecture, Japan. The controls were randomly selected from all singleton babies who were born during the same period as cases in the prefecture. Results:,The number of cases and controls were 286 and 404, respectively. Population attributable fractions of active smoking during and before pregnancy were 7.0% and 8.8%, respectively. Population attributable fraction of passive smoking at home was 15.6% and at the workplace was 1.1%. Combined population attributable fraction of both active and passive smoking was 17.3%. Conclusion:,Public education to eliminate passive smoking for pregnant women and smoking prevention in adolescence is very important in order to reduce the risk of low birth weight. [source] Productivity loss in the workforce: associations with health, work demands, and individual characteristicsAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 1 2009Seyed Mohammad Alavinia MD Abstract Background Decreased productivity at work is an important consequence of the presence of health problems at work. Methods The study population consisted of 2,252 workers in 24 different companies in The Netherlands in 2005,2006 (response 56%). Self-reported loss of productivity on the previous workday was measured on a 10-point numerical rating scale by the Quantity and Quality method. Logistic regression analysis was used to explore the associations between work demands, health problems, individual characteristics, and lifestyle factors with the occurrence of productivity loss. Results About 45% of the workers reported some degree of productivity loss on the previous workday, with an average loss of 11%. Moderate and severe functional limitations due to health problems (OR,=,1.28 and 1.63, respectively) and lack of control at work (OR,=,1.36) were associated with productivity loss at work with population attributable fractions of 7%, 6%, and 16%, respectively. Conclusion Productivity losses at work frequently occur due to health problems and subsequent impairments, and lack of control over the pace and planning of work. This will substantially contribute to indirect costs of health problems among workers. Am. J. Ind. Med. 52:49,56, 2009. © 2008 Wiley-Liss, Inc. [source] Epidemiology of alcohol-related burden of disease among Indigenous AustraliansAUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 2010Bianca Calabria Abstract Objective: To compare the burden of alcohol-related harm and underlying factors of this harm, by age and sex, for Indigenous and general population Australians. Methods: Population attributable fractions are used to estimate the disability adjusted life years (DALYs) for alcohol-related disease and injury. The DALYs were converted to rates per 1,000 by age and sex for the Indigenous and general populations. Results: Homicide and violence rates were much higher for Indigenous males: greatest population difference was for 30,44 years, Indigenous rate 8.9 times higher. Rates of suicide were also greater: the largest population difference was for 15,29 years, Indigenous rate 3.9 times higher. Similarly, for Indigenous females, homicide and violence rates were much higher: greatest population difference was for 30,44 years, Indigenous rate 18.1 times higher. Rates of suicide were also greater: the largest population difference was for 15,29 years, Indigenous rate 5.0 times higher. Conclusions: Alcohol consumption and associated harms are of great concern for Indigenous Australians across all ages. Violent alcohol-related harms have been highlighted as a major concern. Implications: To reduce the disproportionate burden of alcohol-related harm experienced by Indigenous Australians, targeted interventions should include the impact on families and communities and not just the individual. [source] Impact of specific sensitization on asthma and rhinitis in young Brazilian and Chilean adultsCLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2008R. J. Rona Summary Background The pattern of associations and the attributable fractions (AF) of atopic conditions due to specific sensitizations vary between countries. Objective To assess the level of associations and AF between sensitization to five allergens and atopic conditions in two settings. Methods We studied 2063 Brazilians and 1231 Chileans of both sexes using representative samples selected at birth in the 1970s. Information on asthma and rhinitis was based on the European Community Respiratory Health Survey questionnaire. We assessed bronchial hyperresponsiveness (BHR) to methacholine and sensitization to Dermatophagoides pteronyssinus, cat, dog, grass blend and Alternaria alternata. Results The prevalence of sensitization to one or more allergens was 50% in Brazilians and 22% in Chileans. The level of associations varied according to the outcome used. Strong associations between sensitization and asthma, defined as wheeze or awakening with breathlessness at night and positive BHR, were found for each of the five allergens in Chileans [varying from odds ratio (OR) 3.24, 95% confidence interval (CI) 1.47, 7.15 for D. pteronyssinus to 8.44, 95% CI 3.82, 18.66 for cat], whereas the level of associations was restricted to D. pteronyssinus, cat and dog in Brazilians and was somewhat weaker (highest OR 3.90, 95% CI 2.80,5.44). The AF of sensitization on asthma was 54% in Brazil and 44% in Chile. D. pteronyssinus and cat made an independent contribution to asthma in the two samples. The patterns of associations between sensitization and rhino-conjunctivitis were similar to those for asthma. Conclusion The associations between sensitization, and asthma and rhinitis were high in Chile and moderately high in Brazil, but the AF were higher in Brazil, reflecting a higher prevalence of sensitization. In Brazil, dust mite had the greatest impact on atopic conditions while in Chile several allergens had an impact. Sensitization is as serious a problem in Chile and Brazil as in developed countries. [source] | ||||||||||