Review and Assessment of the National League of Cities Assessing State Firefighter Cancer Presumption Laws and Current Firefighter Cancer Research

Transcription

1 Review and Assessment f the Natinal League f Cities Assessing State Firefighter Cancer Presumptin Laws and Current Firefighter Cancer Research The IAFC Safety, Health and Survival Sectin, n behalf f the full membership f the IAFC, cnvened a panel f academic, medical and fire and emergency service health experts t review the Natinal League f Cities Assessing State Firefighter Cancer Presumptin Laws and Current Firefighter Cancer Research. The fllwing is an assessment f the reprt prvided by the panel. Finding 1. The NLC reprt uses a subjective and highly questinable methdlgy t review the literature n cancer amng firefighters. They hand select which articles t review and rely n narrative review methds t draw their cnclusins. Narrative reviews are particularly prne t bias and are widely cnsidered inferir t quantitative review methds. Narrative reviews describe the existing literature using subjective narrative descriptins withut the benefit f quantitative synthesis. They use bx scre r vte cunting methds fr the synthesis f results. These methds can result in inaccurate cnclusins. Narrative reviews are nt precise in their descriptin f study results. As the number f studies included in a narrative review increases, the difficulty f accurately describing verall effects and ptential mderatrs f study utcmes increases. It has been demnstrated that the methds used in narrative reviews can lead t inaccurate cnclusins that are at dds with quantitative reviews and mre recent well-designed trials (Bent et al., 2004; Schmidt et al., 2005; Mulrw et al., 1997). High quality quantitative reviews, like the LeMasters et al. (2006) meta-analysis cited in the reprt, have mre safeguards against bias in inclusin r interpretatin (Ck et al., 1997). LeMasters et al. (2006) reviewed 32 studies evaluating the ccupatinal risk f firefighting with cancer using apprpriate statistical prcedures and cncluded that firefighters have an elevated risk f several types f cancer. Finding 2. The inclusin criteria fr studies used in the NLC reprt are questinable and were nt cnsistently fllwed. Althugh they state that they wuld nt use studies published prir t 1995, they nte in the appendix that they included sme studies prir t 1995 that they cnsidered t be classic studies with n definitive justificatin fr what qualifies as a classic study (see page A-3). April

2 The authrs include tw large review articles (Hwe et al., 1990 and LeMasters et al. 2006) as if they were single r primary studies. It shuld be nted that the LeMasters et al. (2006) was a meta-analysis/quantitative synthesis that derived substantially different cnclusins than the NLC reprt. While LeMaster s et al. (2006) systematic review quantitatively evaluates 32 articles, the NLC review nly cites 17. The NLC review states that nly articles after 1995 are included because this year range, allwed fr the mst recent research studies and dcuments t be cllected and evaluated. Using recently published research studies prvides the mst accurate representatin f the current status and scpe f the prblem under study (p.32). N explanatin is prvided abut why the 18 studies published prir t 1995 r the 4 published in 1995 r later included in the Le Masters et al. (2006) meta-analysis were nt deemed relevant. The NLC reprt excludes a number f studies with large and statistically significant assciatins between firefighting and varius cancers that were included in LeMaster et al. (2006) including: Testicular cancer, risk rati (RR) = 2.5 Arnsn et al. (1994) Malignant melanma, RR = 2.25 Petersn et al. (1980); Milham et al. (1976) Esphageal cancer, RR = 2.03 Beaumnt et al. (1991) Skin cancer, RR = 1.71 Beaumnt et al. (1991) Stmach cancer, RR = 1.58 Trnling et al. (1994) Nn-Hdgkins Lymphma, RR = 1.82 Giles et al. (1993) Thus, they exclude 6 studies with 50% r greater Relative Risk (RR = 1.50 r mre) and 4 studies with a 100% r greater. 100% greater risk fr esphagus, testis, malignant melanma 50% greater risk fr skin, larynx, stmach, nn-hdgkin s lymphma Finding 3. While the reprt authrs nte that the 17 included studies met their definitin f a Class I study (i.e., study in a peer-reviewed, refereed jurnal whse research design, methds, and results have lead t findings that achieved statistical significance), it is telling that sme excluded studies culd have met this definitin if the beginning inclusin date was nt arbitrarily started at In additin, sme studies cited in LeMasters et al. (2006) dated after 1995 als were nt included and we culd find n ratinale fr their exclusin: Ma et al. (1998), case-cntrl study Figgs et al. (1995) case-cntrl study Deschamps et al. (1995) chrt mrtality study Delahunt et al. (1995) case-cntrl study We suggest that this reprt wuld have been f higher quality and greater use if it had been cnducted as a systematic review r meta-analysis. Study quality r rigr culd have been a cded variable and the effect f study quality n utcmes culd have been assessed directly. 2

3 Finding 4. The infrmatin reprted abut the study quality rating system used by the authrs (i.e., Class I Class IV) suggested that the investigatrs ften culd nt reliably classify the studies they reviewed (percent agreement f 73%, see page pp. A-7). The investigatrs disagreed n the quality f a study nearly 30% f the time. Fr the 30% f articles where the tw investigatrs disagreed n the quality f the study, a third f investigatrs slely determined the categry f the study withut any check n their judgment. It is unclear why, given the simple nature f their quality classificatin system, nearly 1/3 f the studies culd nt be reliably classified by the investigatrs. Given the discrete nature f the classificatins and the basic levels at which they were classified, the lw agreement rate is particularly trubling. The authrs inapprpriately use a statistical prcedure used fr rdinal data (Mann Whitney U) t test reliability f assignment t nminal categries. It is unclear why they did nt use the mre cmmnly accepted methd f calculating inter-rater agreement called the Kappa cefficient, which crrects fr agreement by chance alne (see Psner et al., 1990). Thus, it likely that the NLC reprt actually verestimates the reliability f their classificatin system. Finding 5. The NLC reprt adpts strategies used by the tbacc industry fr questining the link between ccupatinal expsures and cancer in firefighters. Despite a large bdy f epidemilgical data which demnstrates an increased risk f cancer in firefighters, the NLC reprt claims a lack f substantive evidence exists t cnclude an increased risk f cancer amng firefighters. The tbacc industry claimed that research was incnclusive and new studies needed t be cnducted even while a large bdy f evidence demnstrated a link between smking and health and that nictine was addictive. The NLC reprt suggests that a new, large, lngitudinal study f firefighters be cnducted that tracks cancer risk ver time. Given that lngitudinal chrt studies take many years t cmplete, this delay strategy bth ignres a large bdy f existing evidence and threatens the health and healthcare f the current generatin f firefighters. The NLC des nt ffer t fund a new, large, lngitudinal chrt study f cancer risk amng firefighters. 3

4 References Bent S, Shjania KG, Saint S. The use f systematic reviews and meta-analyses in infectin cntrl and hspital epidemilgy. AJIC Current Methdlgical Cncepts 2004;32: Ck DJ, Mulrw CD, Haynes RB. Systematic reviews: Synthesis f best evidence fr clinical decisins. Annals f Internal Medicine 1997;126: Psner KL, Sampsn PD, Caplan RA, Ward RJ, Cheney FW. Measuring interrater reliability amng multiple raters: An example f methds fr nminal data. Statistics in Medicine 1990;9: Schmidt LM, Gtzsche PC. Of mites and men: Reference bias in narrative review articles. A systematic review. The Jurnal f Family Practice 2005;54: Panel Participants Sara Pyle, Ph.D. Dr. Pyle is an Assistant Prfessr in the Departments f Family Medicine and the Preventive Medicine and Kansas City University f Medicine and Bisciences. She cmpleted her dctral training in psychlgy with a health emphasis at the University f Missuri Kansas City. She has published nearly 30 peer-reviewed jurnal articles and bk chapters in the area f health behavir research. She recently cmpleted the American Heart Assciatin s Fellwship training n the Epidemilgy and Preventin f Cardivascular Disease. She serves as the Principal Investigatr n a grant frm the American Heart Assciatin and ne frm FEMA n firefighter health and wellness. She is a member f the Internatinal Assciatin f Fire Chiefs Safety, Health and Survival Sectin. Walker S.C. Pstn, Ph.D., MPH. Dr. Pstn is a Senir Scientist and CFO f the HOPE Health Research Institute. He has graduate degrees in the behaviral sciences (University f Califrnia, Santa Barbara) and in cmmunity health and epidemilgy (University f Texas Hustn Health Science Center, Schl f Public Health). Dr. Pstn cmpleted pstdctral fellwships in Clinical Health Psychlgy (Wilfrd Hall Medical Center) and in Cardivascular Health (American Hspital Assciatin Health Frum). He has published ver 160 peerreviewed scientific jurnal articles, bk chapters, and bks n a variety f health related tpics. Dr. Pstn is an elected Fellw in the fllwing scientific rganizatins; 1) the American Cllege f Epidemilgy, 2) the American Heart Assciatin s (AHA) Cuncil n Epidemilgy and Preventin, and 3) The Obesity Sciety (the Nrth American Assciatin fr the Study f Obesity). He serves r has served as the principal investigatr, c-investigatr and/r cnsultant n a number f extramurally-funded grants frm agencies such as the Natinal Institutes f Health, Department f Defense, American Legacy Fundatin, the Department f Hmeland Security, and the American Heart Assciatin. He als has taught graduate curses in epidemilgy, research design, and clinical trials. Dr. Pstn is a C- Investigatr n bth firefighter health studies the team is currently cnducting. C. Keith Haddck, Ph.D. Dr. Haddck is a Senir Scientist and the CEO f the HOPE Health Research Institute. He cmpleted the Statistics and Research Design and the Clinical Psychlgy dctral prgrams at the University f Memphis. He als cmpleted pstdctral fellwships in Health Psychlgy with the U.S. Air Frce and Cardivascular Disease with the American Hspital Assciatin s Health Frum. He is a full member f the American Statistical Assciatin and belngs t the fllwing divisins: Bimetrics, Statistics in Epidemilgy, Health Plicy Statistics, Scial Statistics, Statistical Cnsulting, Survey Research Methds, and Teaching Statistics in the Health Sciences. He is a Fellw f The Obesity Sciety. Dr. Haddck has served as the methdlgist/statistician n a hst f Natinal Institutes f 4

5 Health and Department f Defense research grants and has published ver 130 peer reviewed papers in scientific jurnals. One f Dr. Haddck's mst highly cited statistical articles invlved the develpment f methds t meta-analyze primary studies which have binary utcmes and was published in Psychlgical Methds. Dr. Haddck has taught graduate statistics and research methdlgy, including curses n epidemilgy and clinical trials, multivariate statistical methds, psychmetrics, and statistical prgramming. He has been hnred in Wh's Wh in America, Wh's Wh in Medicine and Health Care, and Wh's Wh Amng America's Teachers. Dr. Haddck is a C-Investigatr n bth firefighter health studies the team is currently cnducting. Richard Suminski, Ph.D., M.P.H.. Dr. Suminski cmpleted his dctrate in Exercise Physilgy and his masters degree in Public Health Epidemilgy frm the University f Pittsburgh. He is currently an Assciate Prfessr in the department f physilgy and Kansas City University f Medicine and Bisciences in Kansas City, MO. Dr. Suminski is a Fellw in the American Cllege f Sprts Medicine and a member f the Obesity Sciety (Nrth American Assciatin fr the Study f Obesity) and has nearly 50 publicatins in peerreviewed jurnals t his credit n health related tpics. Dr. Suminski has been funded by the Centers fr Disease Cntrl and Preventin, the Natinal Institutes f Health and the Rbert Wd Jhnsn Fundatin t cmplete his research n physical activity. Dr. Suminski is a C-Investigatr n bth firefighter health studies the team is currently cnducting. 5