Calculation of Hazard Ratios and Incidence Rate Ratios [posted as supplied by author]

Transcription

1 Calculaton of Hazard Ratos and Incdence Rate Ratos [posted as suppled by author] Where the hazard rato (HR) and a confdence nterval were reported the standard error (SE) of the Log(HR) was obtaned usng [1] [ UppCI ] - LowCI SE[Log(HR)] Φ 1 α [1] Where UppCI and LowCI are the value for the upper and lower ends of the confdence nterval for log(hr ), 1 Φ s the nverse cumulatve normal dstrbuton functon andα s the sgnfcance level or p-value (so 5% n [1]). For studes that reported a HR along wth a p-value from the log-rank test, but no confdence nterval, the SE of the Log(HR) was calculated usng the formula gven n [2] [ Log(HR) ] SE[Log(HR)] = Φ 1 α 1-2 [2] For studes that dd not report results n the form of HRs, but nstead reported the percent that developed type 2 dabetes melltus, ncdence rate ratos (IRRs) were estmated usng nformaton on person years of follow-up. Where person years of follow-up was not reported t was estmated by assumng drop-outs, deaths and development of type 2 dabetes melltus had occurred on average half-way through the tral and therefore these ndvduals added half the tral length to the total person years of follow-up. Those who contnued to the end of the tral attrbuted the full tral length to the total. The ncdence rates could therefore be estmated for each nterventon arm (number of dabetcs dvded by total person years of follow-up) and the IRRs calculated.

2 References to dentfed studes [posted as suppled by author] w1 Knowler WC, Hamman RF, Edelsten SL, Barrett-Connor E, Ehrmann DA, Walker EA, et al. Preventon of type 2 dabetes wth trogltazone n the dabetes preventon program. Dabetes 2005;54: w2 Jarrett RJ, Keen H, Fuller JH, McCartney M. Worsenng to dabetes n men wth mpared glucose tolerance ( borderlne dabetes ). Dabetologa 1979;16: w3 Holman RR, Blackwell L, Stratton IM, Manley SE, Tucker L, Frgh V. Sxyear results from the Early Dabetes Interventon Tral. Dabet Med 2003;20(suppl 2):15. w4 Holman RR, North BV, Tunbrdge FK. Possble preventon of type 2 dabetes wth acarbose or metformn. Dabetes 2000;49(suppl 1):A w5 Sartor G, Schersten B, Carlstrom S, Melander A, Norden A, Persson G. Tenyear follow-up of subjects wth mpared glucose tolerance. Preventon of dabetes by tolbutamde and det regulaton. Dabetes 1980;29:41-9. w6 Swnburn BA, Metcalf PA, Ley SJ. Long-term (5-year) effects of a reducedfat det nterventon n ndvduals wth glucose ntolerance. Dabetes Care 2001;24: w7 Erksson KF, Lndgarde F. Preventon of type 2 (non-nsuln-dependent) dabetes melltus by det and physcal exercse. The 6-year Malmo feasblty study. Dabetologa 1991;34: w8 Erksson KF, Lndgarde F. No excess 12-year mortalty n men wth mpared glucose tolerance who partcpated n the Malmo preventve tral wth det and exercse. Dabetologa 1998;41: w9 Nklason A, Hedner T, Nskanen L, Lanke J, Captoprl Preventon Project Study Group. Development of dabetes s retarded by ACE nhbton n hypertensve patents-a subanalyss of the Captoprl preventon project (CAPPP). J Hypertens 2004;22: w10 Tenenbaum A, Motro M, Fsman EZ, Schwammenthal E, Adler Y, Goldenberg I, et al. Peroxsome prolferator-actvated receptor lgand bezafbrate for preventon of type 2 dabetes melltus n patents wth coronary artery dsease. Crculaton 2004;109: w11 Yusuf S, Gersten H, Hoogwerf B, Pogue J, Bosch J, Wolffenbuttel BH, et al. Ramprl and the development of dabetes. JAMA 2001;286: w12 Costa B. Type 2 dabetes preventon: educaton, or medcaton too?. Med Cln (Barc) 2002;119:613-5.

3 w13 Anonymous. Thoctacd T ncreases glucose utlzaton and reduces nsuln resstance. Munch Med Wochenschr 1996;138(16 suppl):22-5. w14 Mkrtuman AM. Optmal drug therapy of glucose ntolerance s a guarantee of successful preventon of type 2 dabetes melltus. Ter Arkh 2002;74:86-9. w15 Hrose T. Effects of nateglnde n mpared glucose tolerance subjects. Nppon Rnsho 2005;63(suppl 2): w16 Cao H. Effects of lfe style nterventon on early nsuln secreton n the patents wth mpared glucose tolerance. Zhongguo Lnchuang Kangfu 2004;8: w17 Kuzuya H. Preventon of type 2 dabetes n subjects wth mpared glucose tolerance. J Jap Dabetes Soc 2004;47:14-7. w18 Sakane N. Japan dabetes preventon program. Nppon Rnsho 2005;63(suppl 2): w19 Fang YS, L TY, Chen SY. Effect of medcne and non-medcne nterventon on the outcomes of patents wth mpared glucose tolerance: 5-year follow-up. Zhongguo Lnchuang Kangfu 2004;8: w20 Fan GJ, Luo GB, Qn ML. [Effect of jangtang bushen recpe n nterventon treatment of patents wth mpared glucose tolerance.] Zhongguo Zhong X Y Je He Za Zh 2004;24: w21 Tao LL, Deng YB, Fan XB, Bao QD. Effect of exercse tranng n patents wth mpared glucose tolerance. Zhongguo Lnchuang Kangfu 2004;8: w22 Pan XR, L GW, Hu YH, Wang JX, Yang WY, An ZX, et al. Effects of det and exercse n preventng NIDDM n people wth mpared glucose tolerance. The Da Qng IGT and dabetes study. Dabetes Care 1997;20: w23 Knowler WC, Barrett-Connor E, Fowler SE, Hamman RF, Lachn JM, Walker EA, et al. Reducton n the ncdence of type 2 dabetes wth lfestyle nterventon or metformn. N Engl J Med 2002;346: w24 Lndstrom J, Erksson JG, Valle TT, Aunola S, Cepats Z, Hakumak M, et al. Preventon of dabetes melltus n subjects wth mpared glucose tolerance n the Fnnsh dabetes preventon study: results from a randomzed clncal tral. J Am Soc Nephrol 2003;14(suppl 2):S w25 Erksson J, Lndstrom J, Valle T, Aunola S, Hamalanen H, Ilanne- Parkka P, et al. Preventon of tpe II dabetes n subjects wth mpared glucose tolerance: the dabetes preventon study (DPS) n Fnland. Study desgn and 1-year nterm report on the feasblty of the lfestyle nterventon programme. Dabetologa 1999;42:

4 w26 Jarrett RJ, Keen H, McCartney P. The Whtehall study: ten year follow-up report on men wth mpared glucose tolerance wth reference to worsenng to dabetes and predctors of death. Dabet Med 1984;1: w27 Kosaka K, Noda M, Kuzuya T. Preventon of type 2 dabetes by lfestyle nterventon: a Japanese tral n IGT males. Dabetes Res Cln Pract 2005;67: w28 Heymsfeld SB, Segal KR, Hauptman J, Lucas CP, Boldrn MN, Rssanen A, et al. Effects of weght loss wth orlstat on glucose tolerance and progresson to type 2 dabetes n obese adults. Arch Intern Med 2000;160: w29 Lao D, Asberry PJ, Shofer JB, Callahan H, Matthys C, Boyko EJ, et al. Improvement of BMI, body composton, and body fat dstrbuton wth lfestyle modfcaton n Japanese Amercans wth mpared glucose tolerance. Dabetes Care 2002;25: w30 L CL, Pan CY, Lu JM, Zhu Y, Wang JH, Deng XX, et al. Effect of metformn on patents wth mpared glucose tolerance. Dabet Med 1999;16: w31 Pan CY, Gao Y, Chen JW, Luo BY, Fu ZZ, Lu JM, et al. Effcacy of acarbose n Chnese subjects wth mpared glucose tolerance. Dabetes Res Cln Pract 2003;61: w32 Chasson JL, Goms R, Hanefeld M, Josse RG, Karask A, Laakso M. The STOP-NIDDM tral: an nternatonal study on the effcacy of an alpha-glucosdase nhbtor to prevent type 2 dabetes n a populaton wth mpared glucose tolerance: ratonale, desgn, and prelmnary screenng data. Study to prevent non-nsulndependent dabetes melltus. Dabetes Care 1998;21: w33 Chasson JL, Josse RG, Goms R, Hanefeld M, Karask A, Laakso M. Acarbose for preventon of type 2 dabetes melltus: the STOP-NIDDM randomsed tral. Lancet 2002;359: w34 Buchanan TA, Xang AH, Peters RK, Kjos SL, Marroqun A, Goco J, et al. Preservaton of pancreatc beta-cell functon and preventon of type 2 dabetes by pharmacologcal treatment of nsuln resstance n hgh-rsk Hspanc women. Dabetes 2002;51: w35 Wen P, Bescher N, Harrs C, Permezel M. A tral of smple versus ntensfed detary modfcaton for preventon of progresson to dabetes melltus n women wth mpared glucose tolerance. Aust N Z J Obstet Gynaecol 1999;39: w36 Keen H, Jarrett RJ, Ward JD, Fuller JH. Borderlne dabetcs and ther response to tolbutamde. Adv Metab Dsord 1973;2(suppl 2):

5 w37 Torgerson JS, Hauptman J, Boldrn MN, Sjostrom L. XENcal n the preventon of dabetes n obese subjects (XENDOS) study: a randomzed study of orlstat as an adjunct to lfestyle changes for the preventon of type 2 dabetes n obese patents. Dabetes Care 2004;27: w38 Erksson JG, Lehtovrta M, Ehrnstrom B, Salmela S, Groop L. Long-term benefcal effects of glpzde treatment on glucose tolerance n subjects wth mpared glucose tolerance. J Intern Med 2006;259: w39 Ramachandran A, Snehalatha C, Mary S, Mukesh B, Bhaskar AD, Vjay V. The Indan dabetes preventon programme shows that lfestyle modfcaton and metformn prevent type 2 dabetes n Asan Indan subjects wth mpared glucose tolerance (IDPP-1). Dabetologa 2006;49: The IRRs were transformed to the log scale for the meta-analyses, and the standard error of the estmated Log(IRR)s was calculated usng [3], where d t and d c were the numbers who developed type 2 dabetes melltus n the treatment and control arms respectvely. SE[Log(IRR)] [3] d t d c The Da Qng tral assessed three dfferent lfestyle nterventons whch resulted n multple use of the same control group n a sngle meta-analyss. To adjust for ths the number of dabetcs and estmated person years for the control group was dvded by the number of nterventons from the tral, and the IRRs then calculated, effectvely usng a proporton of the control group. Furthermore, as the Da Qng study was randomsed at the clnc level, the consequental clusterng effect was adjusted for by reanalysng the reported data by fttng a Poson regresson model, wth clnc ncluded as a random effect.

6 Pharmacologcal and lfestyle nterventons to prevent or delay type 2 dabetes melltus n ndvduals wth mpared glucose tolerance: A Systematc Revew and Meta-analyss Clare L Glles, Keth R Abrams, Paul C Lambert, Ncola J Cooper, Ron Hsu,, Alex J Sutton, Kamlesh Khunt Search strategy Both Medlne (1966 to July, week 3, 2006) and Embase (1980 to week 29, 2006) databases were searched usng the followng search terms. RCT flter 1. randomzed controlled tral.pt. 2. controlled clncal tral.pt. 3. Randomzed Controlled Trals/ 4. random allocaton/ 5. double blnd method/ 6. sngle-blnd Method/ 7. clncal tral.pt. 8. clncal trals/ 9. clncal tral.tw. 10. ((sngl$ or doubl$ or trebl$ or trpl$) and (mask$ or blnd$)).tw. 11. PLACEBOS/ 12. placebo$.tw. 13. random$.tw. 14. (cln$ adj5 tral$).t,ab. 15. or/ (anmals not human).sh not 16 Type II dabetes 18. dabetes-melltus,-non-nsuln-dependent/ 19. nsuln-resstance/ 20. obesty-n-dabetes.mp. or Obesty n Dabetes/ 21. (MODY or DM2 or NIDDM or IIDM).t,ab. 22. (non nsuln$ depend$ or nonnsuln$ depend$).t,ab. 23. (("typ$ 2" or typ$ II) adj10 (dabet$ or DM)).t,ab. 24. (nsuln$ defc$ adj5 relatv$).t,ab. 25. (adult$ onset or matur$ onset or late$ onset).mp. [mp=ttle, orgnal ttle, abstract, name of substance, mesh subject headng] or 19 or 20 or 21 or 22 or 23 or 24 or 25 Preventon combned wth type II dabetes (usng and) 27. "PREVENTIVE MEDICINE"/ 28. "PREVENTIVE-HEALTH-SERVICES"/ 29. (PREVENT$ or PROPHYLA$ or AVOID$ or DELAY$).t,ab and (27 or 28 or 29) Exclusons 31. "dermatomyosts".mp. or DERMATOMYOSITIS/ 32. "myotonc-dystrophy"/ 33. exp Dabetes Inspdus/ 34. melltus.t,ab not (18 or 34) 36. (dabet$ adj5 (nspdus not melltus)).t,ab. 37. ((keto$ resst$ or nonketo$ or non keto$ or slow onset or stabl$) adj5 (dabet$ or

7 DM or DM2)).mp. [mp=ttle, orgnal ttle, abstract, name of substance, mesh subject headng] 38. (fragl$ X or X lnked).mp. [mp=ttle, orgnal ttle, abstract, name of substance, mesh subject headng] 39. (plurmetabolc$ syndrom$ or plur metabolc$ syndrom$).mp. [mp=ttle, orgnal ttle, abstract, name of substance, mesh subject headng] 40. "PREGNANCY-IN-DIABETES".t,ab. 41. (pregnan$ adj5 dabet$).t,ab or 32 or 35 or 36 or 37 or 38 or 39 or 40 or not 42 IGT and smlar condtons 44. "predabetc-state"/ 45. ((predabet$ or pre dabet$) adj5 state).t,ab. 46. "glucose-ntolerance"/ 47. (mpared glucose tolerance or glucose ntoleran$ or nsuln$ resst$).t,ab. 48. mpared fastng glucose.t,ab. 49. (IGT or IFG).tw. 50. (metabolc syndrome or syndrome x).mp. [mp=ttle, orgnal ttle, abstract, name of substance, mesh subject headng] 51. "hypernsulnema"/ 52. (hypernsuln$ or hyper nsuln$).t,ab. 53. glucose tolerance test.tw. 54. mpared fastng blood glucose.tw. 55. (mpared fastng glycaema or mpared fastng glycema).tw. 56. (mpared glucose stat$ or mpared glucose respons$ or mpared glucose control$).tw. 57. (mpared glucose regul$ or mpared glucose metab$).tw. 58. (mpared glucose homeost$ or reduced glucose metab$).tw. 59. (reduced glucose toleran$ or glucose ntolerant$).tw. 60. (predabet$ or praedabet$).tw. 61. (borderlne dabet$ or mld dabet$).tw. 62. (mpared nsuln secret$ or reduced nsuln secret$).tw or 45 or 46 or 47 or 48 or 49 or 50 or 51 or 52 or 53 or 54 or 55 or 56 or 57 or 58 or 59 or 60 or 61 or 62 IGT + ((dabetes and preventon)-exclusons) or 43 Above combned wth RCT (usng and) and 17