Publications 2007

(1)    Adams N, Lasserson T, Cates C, Jones P. Fluticasone versus beclomethasone or budesonide for chronic asthma in adults and children. Cochrane Database Syst Rev 2007;CD002310.

(2) Addo-Yobo EO, Woodcock A, Allotey A, Baffoe-Bonnie B, Strachan DP, Custovic A. Exercise-induced bronchospasm and atopy in Ghana: two surveys ten years apart. PLoS Med 2007; 4:e70.

(3) Adlerberth I, Strachan DP, Matricardi PM, Ahrne S, Orfei L, Aberg N, Perkin MR, Tripodi S, Hesselmar B, Saalman R, Coates AR, Bonanno CL, Panetta V, Wold AE. Gut microbiota and development of atopic eczema in 3 European birth cohorts. J Allergy Clin Immunol 2007; 120:343-350.

(4) Anderson HR, Gupta R, Strachan DP, Limb ES. 50 years of asthma: UK trends from 1955 to 2004. Thorax 2007; 62:85-90.

(5) Atherton H, Banks D, Harbit R, Long L, Chadd F, Hay P, Kerry S, Simms I, Oakeshott P. Recruitment of young women to a trial of chlamydia screening - as easy as it sounds? Trials 2007; 8:41.

(6) Aveyard P, Ussher M. Does exercise in adolescence prevent smoking uptake? Addiction 2007; 102:1025-1026..

(7) Bradley JM, Lasserson T, Elborn S, Macmahon J, O'neill B. A systematic review of randomized controlled trials examining the short-term benefit of ambulatory oxygen in COPD. Chest 2007; 131:278-285.

(8) Bremner SA, Carey IM, Dewilde S, Richards N, Maier WC, Hilton SR, Strachan DP, Cook DG. Vaccinations, infections and antibacterials in the first grass pollen season of life and risk of later hayfever. Clin Exp Allergy 2007; 37:512-517.

(9) Butland B, Strachan DP. Asthma onset and relapse in adult life: the British 1958 birth cohort study. Annals of Allergy, Asthma and Immunology 2007; 98:337-343.

(10) Cahill K, Ussher M. Cannabinoid type 1 receptor antagonists (rimonabant) for smoking cessation. Cochrane Database Syst Rev 2007;CD005353.

(11) Carey IM, Dewilde S, Harris T, Whincup PH, Cook DG. Spurious trends in coronary heart disease incidence: unintended consequences of the new GP contract? British Journal of General Practice 2007; 57:486-489.

(12) Cates CJ. Current challenges in asthma. Br J Gen.Pract. 2007;57:179-180.

(13) Crinson I. Nursing practice and organisational change within the NHS : A critical realist methodological approach to the analysis of discursive data. Methodological Innovations Online 2007;2

(14) Crinson I, Shaw A, Durrant R, de Lusignan S, Williams B. Coronary heart disease and the management of risk: Patient perspectives of outcomes associated with the clinical implementation of the National Service Framework targets. Health, Risk & Society 2007; 9:359-373.

(15) Cropley M, Ussher M, Charitou E. Acute effects of a guided relaxation routine (body scan) on tobacco withdrawal symptoms and cravings in abstinent smokers. Addiction 2007; 102:989-993.

(16) Danesh J, Whincup PH, et al. The Emerging Risk Factors Collaboration: analysis of individual data on lipid, inflammatory and other markers in over 1.1 million participants in 104 prospective studies of cardiovascular diseases. Eur J Epidemiol 2007; 22:839-869.

(17) de Lusignan S, Chan T, Theadom A, Dhoul N. The roles of policy and professionalism in the protection of processed clinical data: A literature review. International Journal of Medical Informatics 2007; 76:261-268.

(18) de Lusignan S. An educational intervention, involving feedback of routinely collected computer data, to improve cardiovascular disease management in UK primary care. Methods Inf Med 2007; 46:57-62.

(19) de Lusignan S, Katic M. UK and Croatia: family practice, its medical records and computerisation in the context of an enlarged Europe. Inform Prim Care 2007; 15:169-173.

(20) De Wilde S., Carey IM, Harris T, Richards N, Victor C, Hilton SR, Cook DG. Trends in potentially inappropriate prescribing amongst older UK primary care patients. Pharmacoepidemiol Drug Saf 2007; 16:658-667.

(21) Dean SC, Kerry SM, Cappuccio FP, Oakeshott P. Pilot study of potential barriers to blood pressure control in patients with inadequately controlled hypertension. Fam Pract 2007; 24:259-262.

(22) Edgar D, Rudnicka AR, (editors). Glaucoma: Identification and Co-management. London: Butterworth Heinemann; 2007.

(23) Everson ES, Daley AJ, Ussher M. Brief report: The theory of planned behaviour applied to physical activity in young people who smoke. J Adolesc 2007; 30:347-351.

(24) Field-Smith ME, Butland BK, Ramsey JD, Anderson HR. Trends in death associated with abuse of volatile substances 1971-2005. 20. 2007.St George's University of London, Division of Community Health Sciences.

(25) Freathy RM, Weedon MN, Bennett A, Hypponen E, Relton CL, Knight B, Shields B, Parnell KS, Groves CJ, Ring SM, Pembrey ME, Ben-Shlomo Y, Strachan DP, Power C, Jarvelin MR, McCarthy MI, Davey SG, Hattersley AT, Frayling TM. Type 2 diabetes TCF7L2 risk genotypes alter birth weight: a study of 24,053 individuals. Am J Hum Genet 2007; 80:1150-1161.

(26) Garrod R, Lasserson T. Role of physiotherapy in the management of chronic lung diseases: an overview of systematic reviews. Respir Med 2007; 101:2429-2436.

(27) Gulzar Z, Goff S, Njindou A, Hearty H, Rafi I, Savage R, Matta G, Ferras J, Hodgson S. Nurse-led cancer genetics clinics in primary and secondary care in varied ethnic population areas: interaction with primary care to improve ascertainment of individuals from ethnic minorities. Fam Cancer 2007; 6:205-212.

(28) Gupta R, Sheikh A, Strachan DP, Anderson HR. Time trends in allergic disorders in the UK. Thorax 2007; 62:91-96.

(29) Hasan A, Poloniecki JD, Child A. Ageing in Marfan syndrome. International Journal of Clinical Practice 2007; 61:1308-1320.

(30) Holt PJ, Poloniecki JD, Loftus IM, Michaels JA, Thompson MM. Epidemiological study of the relationship between volume and outcome after abdominal aortic aneurysm surgery in the UK from 2000 to 2005. Br J Surg 2007; 94:441-448.

(31) Holt PJ, Poloniecki JD, Gerrard D, Loftus IM, Thompson MM. Meta-analysis and systematic review of the relationship between volume and outcome in abdominal aortic aneurysm surgery. Br J Surg 2007; 94:395-403.

(32) Holt PJ, Poloniecki JD, Loftus IM, Thompson MM. Meta-Analysis and Systematic Review of the Relationship between Hospital Volume and Outcome Following Carotid Endarterectomy. Eur J Vasc Endovasc Surg 2007; 33:645-651.

(33) Holt PJ, Poloniecki JD, Loftus IM, Thompson MM. The relationship between hospital case volume and outcome from carotid endartectomy in England from 2000 to 2005. Eur J Vasc Endovasc Surg 2007; 34:646-654.

(34) Huxley R, Owen CG, Whincup PH, Cook DG, Rich-Edwards J, Smith GD, Collins R. Is birth weight a risk factor for ischemic heart disease in later life? Am J Clin Nutr 2007; 85:1244-1250.

(35) Khan S, Cloud GC, Kerry S, Markus HS. Imaging of vertebral artery stenosis: a systematic review. J Neurol Neurosurg Psychiatry 2007; 78:1218-1225.

(36) Klebe B, Farmer C, Cooley R, de Lusignan S, Middleton R, O'donoghue D, New J, Stevens P. Kidney disease management in UK primary care: guidelines, incentives and Information Technology. Fam Pract 2007; 24:330-335.

(37) Klebe B, Irving J, Stevens PE, O'Donoghue DJ, de Lusignan S, Cooley R, Hobbs H, Lamb EJ, John I, Middleton R, New J, Farmer CK. The cost of implementing UK guidelines for the management of chronic kidney disease. Nephrol Dial Transplant 2007; 22:2504-2512.

(38) Koh MS, Tee A, Lasserson TJ, Irving LB. Inhaled corticosteroids compared to placebo for prevention of exercise induced bronchoconstriction. Cochrane Database Syst Rev 2007;CD002739.

(39) Kumarapeli P, de Lusignan S, Ellis T, Jones B. Using Unified Modelling Language (UML) as a process-modelling technique for clinical-research process improvement. Med Inform Internet Med 2007; 32:51-64.

(40) Lacasse Y, Martin S, Lasserson TJ, Goldstein RS. Meta-analysis of respiratory rehabilitation in chronic obstructive pulmonary disease. A Cochrane systematic review. Eura Medicophys 2007; 43:475-485.

(41) Leontowitz M, Higgs P, Stevenson F, Jones IR. New contract runs risk of distracting pharmacists from helping the over 60s. PJ 278, 520. 2007.

(42) Mahmood D, Vartzelis G, McQueen P, Perkin MR. Radiological follow-up of pediatric pneumonia: principle and practice. Clin Pediatr (Phila) 2007; 46:160-162.

(43) Marossy AE, Strachan DP, Rudnicka AR, Anderson HR. Childhood chest illness and the rate of decline of adult lung function between ages 35 and 45 years. Am J Respir Crit Care Med 2007; 175:355-359.

(44) May M, Sterne JA, Shipley M, Brunner E, d'Agostino R, Whincup P, Ben-Shlomo Y, Carr A, Ledergerber B, Lundgren JD, Phillips AN, Massaro J, Egger M. A coronary heart disease risk model for predicting the effect of potent antiretroviral therapy in HIV-1 infected men. Int J Epidemiol 2007; 36:1309-1318.

(45) Michelozzi P, Kirchmayer U, Katsouyanni K, Biggeri A, McGregor G, Menne B, Kassomenos P, Anderson HR, Baccini M, Accetta G, Analytis A, Kosatsky T. Assessment and prevention of acute health effects of weather conditions in Europe, the PHEWE project: background, objectives, design. Environ Health 2007; 6:12.

(46) Moffatt MF, Kabesch M, Liang L, Dixon AL, Strachan D, Heath S, Depner M, von BA, Bufe A, Rietschel E, Heinzmann A, Simma B, Frischer T, Willis-Owen SA, Wong KC, Illig T, Vogelberg C, Weiland SK, von ME, Abecasis GR, Farrall M, Gut IG, Lathrop GM, Cookson WO. Genetic variants regulating ORMDL3 expression contribute to the risk of childhood asthma. Nature 2007; 448:470-473.

(47) Moulene MV, de LS, Freeman G, Van VJ, Sheeler I, Singleton A, Kumarapeli P. Assessing the impact of recording quality target data on the GP consultation using multi-channel video. Medinfo 2007; 12:1132-1136.

(48) Nannini L, Cates CJ, Lasserson TJ, Poole P. Combined corticosteroid and long-acting beta-agonist in one inhaler versus placebo for chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2007;CD003794.

(49) Nannini LJ, Cates CJ, Lasserson TJ, Poole P. Combined corticosteroid and long-acting beta-agonist in one inhaler versus inhaled steroids for chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2007;CD006826.

(50) Nannini LJ, Cates CJ, Lasserson TJ, Poole P. Combined corticosteroid and long-acting beta-agonist in one inhaler versus long-acting beta-agonists for chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2007;CD006829.

(51) Nejentsev S, Howson JM, Walker NM, Szeszko J, Field SF, Stevens HE, Reynolds P, Hardy M, King E, Masters J, Hulme J, Maier LM, Smyth D, Bailey R, Cooper JD, Ribas G, Campbell RD, Clayton DG, Todd JA, The Wellcome Trust Case Control Consortium, Strachan DP. Localization of type 1 diabetes susceptibility to the MHC class I genes HLA-B and HLA-A. Nature 2007; 450:887-892.

(52) New JP, Middleton RJ, Klebe B, Farmer CK, de Lusignan S, Stevens PE, O'Donoghue DJ. Assessing the prevalence, monitoring and management of chronic kidney disease in patients with diabetes compared with those without diabetes in general practice. Diabet Med 2007; 24:364-369.

(53) Oakeshott P, Hunt GM, Whitaker RH, Kerry S. Perineal sensation: an important predictor of long-term outcome in open spina bifida. Arch Dis Child 2007; 92:67-70.

(54) Oakeshott P, Graham A. NICE guidance on one-to-one interventions to reduce sexually transmitted infections and under-18 conceptions: a view from general practice. Sex Transm.Infect. 2007; 83:171-172.

(55) Parkes M, Barrett JC, Prescott NJ, Tremelling M, Anderson CA, Fisher SA, Roberts RG, Nimmo ER, Cummings FR, Soars D, Drummond H, Lees CW, Khawaja SA, Bagnall R, Burke DA, Todhunter CE, Ahmad T, Onnie CM, McArdle W, Strachan DP, Bethel G, Bryan C, Lewis CM, Deloukas P, Forbes A, Sanderson J, Jewell DP, Satsangi J, Mansfield JC, Cardon L, Mathew CG. Sequence variants in the autophagy gene IRGM and multiple other replicating loci contribute to Crohn's disease susceptibility. Nat Genet 2007; 39:830-832.

(56) Peacock J, Kerry S. Presenting medical statistics from proposal to publication: a step by step guide. Oxford University Press; 2007.

(57) Perkin MR. Unpasteurized milk: health or hazard? Clin.Exp.Allergy 2007; 37 627-630..

(58) Petsky HL, Kynaston JA, Turner C, Li AM, Cates CJ, Lasserson TJ, Chang AB. Tailored interventions based on sputum eosinophils versus clinical symptoms for asthma in children and adults. Cochrane Database Syst Rev 2007;CD005603.

(59) Pigott K, de Lusignan S, Rapley A, Robinson J, Pritchard-Copley A. An informatics benchmarking statement. Methods Inf.Med. 2007 46 394-398..

(60) Poulton J, Oakeshott P, Kennedy S. Difficulties and possible solutions in the genetic management of mtDNA disease in the preimplantation embryo. In: Justin St.John, editor. The Mitochondrion in the Germline and Early Development. Academic Press; 2007. 213.

(61) Power C, Atherton K, Strachan DP, Shepherd P, Fuller E, Davis A, Gibb I, Kumari M, Lowe G, Macfarlane GJ, Rahi J, Rodgers B, Stansfeld S. Life-course influences on health in British adults: effects of socio-economic position in childhood and adulthood. Int J Epidemiol 2007; 36:532-539.

(62) Rafi I, Spicer J. Genetics and Primary Care: an introductory guide. Oxford: Radcliffe Publishing Ltd; 2007.

(63) Ramsay SE, Whincup PH, Morris RW, Lennon LT, Wannamethee S. Are childhood socio-economic circumstances related to coronary heart disease risk? Findings from a population-based study of older men. Int J Epidemiol 2007; 36:560-566.

(64) Ramsay SE, Whincup PH, Wannamethee SG, Papacosta O, Lennon L, Thomas MC, Morris RW. Missed opportunities for secondary prevention of cerebrovascular disease in elderly British men from 1999 to 2005: a population-based study. J Public Health (Oxf) 2007; 29:251-257.

(65) Roche A, Heath PT, Sharland M, Strachan D, Breathnach A, Haigh J, Young Y. Prevalence of nasopharyngeal carriage of pneumococcus in preschool children attending day care in London. Arch Dis Child 2007; 92:1073-1076.

(66) Rudnicka AR, Owen CG, Strachan DP. The effect of breastfeeding on cardiorespiratory risk factors in adult life. Pediatrics 2007; 119:e1107-e1115.

(67) Rudnicka AR, Owen CG. Epidemiology of primary open angle glaucoma. In: Edgar D, Rudnicka AR, editors. Butterworth Heinemann; 2007. 1-16.

(68) Rudnicka AR, Rumley A, Lowe GD, Strachan DP. Diurnal, seasonal, and blood-processing patterns in levels of circulating fibrinogen, fibrin D-dimer, C-reactive protein, tissue plasminogen activator, and von Willebrand factor in a 45-year-old population. Circulation 2007; 115:996-1003.

(69) Samoli E, Touloumi G, Schwartz J, Anderson HR, Schindler C, Forsberg B, Vigotti MA, Vonk J, Kosnik M, Skorkovsky J, Katsouyanni K. Short-term effects of carbon monoxide on mortality: an analysis within the APHEA project. Environ Health Perspect 2007; 115:1578-1583.

(70) Shaheen SO, Hines M, Newson RB, Wheeler M, Herrick DR, Strachan DP, Jones RW, Burney PG, Henderson AJ. Maternal testosterone in pregnancy and atopic outcomes in childhood. Allergy 2007; 62:25-32.

(71) Sheeler I, Koczan P, Wallage W, de Lusignan S. Low-cost three-channel video for assessment of the clinical consultation. Inform Prim Care 2007; 15:25-31.

(72) Stevens PE, O'Donoghue DJ, de Lusignan S, Van Vlymen J, Klebe B, Middleton R, Hague N, New J, Farmer CK. Chronic kidney disease management in the United Kingdom: NEOERICA project results. Kidney Int 2007; 72:92-99.

(73) Strachan DP, Rudnicka AR, Power C, Shepherd P, Fuller E, Davis A, Gibb I, Kumari M, Rumley A, Macfarlane GJ, Rahi J, Rodgers B, Stansfeld S. Lifecourse influences on health among British adults: effects of region of residence in childhood and adulthood. Int J Epidemiol 2007; 36:522-531.

(74) Strazzullo P, Kerry SM, Barbato A, Versiero M, D'Elia L, Cappuccio FP. Do statins reduce blood pressure?: a meta-analysis of randomized, controlled trials. Hypertension 2007; 49:792-798.

(75) Tai TW, Anandarajah S, Dhoul N, de LS. Variation in clinical coding lists in UK general practice: a barrier to consistent data entry? Inform Prim Care 2007; 15:143-150.

(76) Tapp S, Lasserson TJ, Rowe B. Education interventions for adults who attend the emergency room for acute asthma. Cochrane Database Syst Rev 2007;CD003000.

(77) Taylor AH, Ussher MH, Faulkner G. The acute effects of exercise on cigarette cravings, withdrawal symptoms, affect and smoking behaviour: a systematic review. Addiction 2007; 102:534-543.

(78) Tee AK, Koh MS, Gibson PG, Lasserson TJ, Wilson AJ, Irving LB. Long-acting beta2-agonists versus theophylline for maintenance treatment of asthma. Cochrane Database Syst Rev 2007;CD001281.

(79) The Wellcome Trust Case Control Consortium, Strachan DP, et al. Genome-wide association study of 14,000 cases of seven common diseases and 3,000 shared controls. Nature 2007; 447:661-678.

(80) The Wellcome Trust Case Control Consortium, Strachan DP, et al. Association scan of 14,500 nonsynonymous SNPs in four diseases identifies autoimmunity variants. Nat Genet 2007; 39:1329-1337.

(81) Thomson W, Barton A, Ke X, Eyre S, Hinks A, Bowes J, Donn R, Symmons D, Hider S, Bruce IN, Wilson AG, Marinou I, Morgan A, Emery P, Carter A, Steer S, Hocking L, Reid DM, Wordsworth P, Harrison P, Strachan D, Worthington J. Rheumatoid arthritis association at 6q23. Nat Genet 2007; 39:1431-1433.

(82) Turner D, Tarrant C, Windridge K, Bryan S, Boulton M, Freeman G, Baker R. Do patients value continuity of care in general practice? An investigation using stated preference discrete choice experiments. J Health Serv Res Policy 2007; 12:132-137.

(83) Tyler K, Patton M, Mongiello M, Meyer D. Service business markets: a further view of a new reality or a blurred landscape? Journal of Services Marketing 2007. 21: 295-303.

(84) Ussher MH, Stanbury L, Cheeseman V, Faulkner G. Brief report: Physical Activity Preferences and Perceived Barriers to Activity Among Persons With Severe Mental Illness in the United Kingdom. Psychiatr Serv 2007; 58:405-408.

(85) Ussher MH. Physical Activity and Smoking Cessation. Why people smoke: Multiple Motives Approach to Tobacco Dependence. European Network for Smoking Prevention; 2007;. 63-69.

(86) Ussher MH. Physical activity interventions. In: Ayers SBA, McManus C, Newman S, Wallston K, Weinman J, West R, editors. Cambridge Handbook of Psychology, Health and Medicine. 2 ed. Cambridge University Press; 2007; 375-379.

(87) Ussher MH, Owen CG, Cook DG, Whincup PH. The relationship between physical activity, sedentary behaviour and psychological wellbeing among adolescents. Soc Psychiatry Psychiatr Epidemiol 2007; 42:851-856.

(88) Ussher MH, West R, McEwen A, Taylor A, Steptoe A. Randomized controlled trial of physical activity counseling as an aid to smoking cessation: 12 month follow-up. Addict Behav 2007; 32:3060-3064.

(89) Ussher MH, Ah-Yoon M. Factors Associated With Exercise Participation and Attitudes to Exercise Among Pregnant Smokers. Journal of Smoking Cessation 2007; 2:12-16.

(90) Vasquez-Cupeiro S, Leontowitz M. Hard, brave and charming - exploring the conditions of success in British universities. In: Siemienska R, Zimmer R, editors. Gendered career trajectories in academia in cross national perspective. Warsaw: SCOLAR; 2007. 267-297.

(91) Walters EH, Gibson PG, Lasserson TJ, Walters JA. Long-acting beta2-agonists for chronic asthma in adults and children where background therapy contains varied or no inhaled corticosteroid. Cochrane Database Syst Rev 2007;CD001385.

(92) Wannamethee SG, Tchernova J, Whincup P, Lowe GDO, Kelly A, Rumley A, Wallace AM, Sattar N. Plasma leptin: Associations with metabolic, inflammatory and haemostatic risk factors for cardiovascular disease. Atherosclerosis 2007; 191:418-426.

(93) Wannamethee SG, Lowe GD, Rumley A, Cherry L, Whincup PH, Sattar N. Adipokines and risk of type 2 diabetes in older men. Diabetes Care 2007; 30:1200-1205.

(94) Wannamethee SG, Whincup PH, Rumley A, Lowe GD. Inter-relationships of interleukin-6, cardiovascular risk factors and the metabolic syndrome among older men. J Thromb Haemost 2007; 5:1637-1643.

(95) Wannamethee SG, Whincup PH, Lennon L, Sattar N. Circulating adiponectin levels and mortality in elderly men with and without cardiovascular disease and heart failure. Arch Intern Med 2007; 167:1510-1517.

(96) Wannamethee SG, Tchernova J, Whincup P, Lowe GD, Rumley A, Brown K, Cherry L, Sattar N. Associations of adiponectin with metabolic and vascular risk parameters in the British Regional Heart Study reveal stronger links to insulin resistance-related than to coronory heart disease risk-related parameters. Int J Obes (Lond) 2007; 31:1089-1098.

(97) Wannamethee SG, Shaper AG, Lennon L, Whincup PH. Decreased muscle mass and increased central adiposity are independently related to mortality in older men. Am J Clin Nutr 2007; 86:1339-1346.

(98) Weinmayr G, Weiland SK, Bjorksten B, Brunekreef B, Buchele G, Cookson WOC, Garcia-Marcos L, Gotua M, Gratziou C, van Hage M, von Mutius E, Riikjarv MA, Rzehak P, Stein RT, Strachan DP, Tsanakas J, Wickens K, Wong GW, and the ISAAC Phase Two Study Group. Atopic Sensitization and the International Variation of Asthma Symptom Prevalence in Children. American Journal of Respiratory and Critical Care Medicine 2007; 176:565-574.

(99) Yang IA, Fong KM, Sim EH, Black PN, Lasserson TJ. Inhaled corticosteroids for stable chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2007;CD002991.

(100) Zeggini E, Weedon MN, Lindgren CM, Frayling TM, Elliott KS, Lango H, Timpson NJ, Perry JR, Rayner NW, Freathy RM, Barrett JC, Shields B, Morris AP, Ellard S, Groves CJ, Harries LW, Marchini JL, Owen KR, Knight B, Cardon LR, Walker M, Hitman GA, Morris AD, Doney AS, Strachan DP, Wellcome Trust Case Consortium. Replication of genome-wide association signals in UK samples reveals risk loci for type 2 diabetes. Science 2007; 316:1336-1341.

(101) Zhai G, Valdes AM, Cherkas L, Clement G, Strachan D, Spector TD. The Interaction of Genes and Smoking on Forced Expiratory Volume: A Classic Twin Study. Chest 2007; 132:1772-1777.