[ Originl Reserch COPD ] Trends in Mortlity From COPD Among Adults in the United Sttes Erl S. Ford, MD, MPH BACKGROUND: COPD imposes lrge public helth burden interntionlly nd in the United Sttes. The objective of this study ws to exmine trends in mortlity from COPD mong US dults from 1968 to 2011. METHODS: Dt from the Ntionl Vitl Sttistics System from 1968 to 2011 for dults ged 25 yers were ccessed, nd trends in mortlity rtes were exmined with Joinpoint nlysis. RESULTS: Among ll dults, ge-djusted mortlity rte rose from 29.4 per 100,000 popultion in 1968 to 67.0 per 100,000 popultion in 1999 nd then declined to 63.7 per 100,000 popultion in 2011 (nnul percentge chnge [APC] 2000-2011, 20.2%; 95% CI, 20.6 to 0.2). The gedjusted mortlity rte mong men peked in 1999 nd then declined (APC 1999-2011, 21.1%; 95% CI, 21.4 to 20.7), wheres the ge-djusted mortlity rte mong women incresed from 2000 to 2011, peking in 2008 (APC 2000-2011, 0.4%; 95% CI, 0.0-0.9). Despite nrrowing of the sex gp, mortlity rtes in men continued to exceed those in women. Evidence of decline in the APC ws noted for blck men (1999-2011, 21.5%; 95% CI, 22.1 to 21.0) nd white men (1999-2011, 20.9%; 95% CI, 21.3 to 20.6), dults ged 55 to 64 yers (1989-2011, 21.0%; 95% CI, 21.2 to 20.8), nd dults ged 65 to 74 yers (1999-2011, 21.2%; 95% CI, 21.6 to 20.9). CONCLUSIONS: In the United Sttes, the mortlity rte from COPD hs declined since 1999 in men nd some ge groups but ppers to be still rising in women, lbeit t reduced pce. CHEST 2015; 148(4): 962-970 Mnuscript received September 17, 2014; revision ccepted October 22, 2014; originlly published Online First November 20, 2014. ABBREVIATIONS: APC 5 nnul percentge chnge; ICD-8 5 Eighth Revision, Interntionl Clssifiction of Diseses, Adpted for Use in the United Sttes; ICD-9 5 Interntionl Clssifiction of Diseses, Ninth Revision; ICD-10 5 Interntionl Clssifiction of Diseses, 10th Revision AFFILIATIONS: From the Division of Popultion Helth, Ntionl Center for Chronic Disese Prevention nd Helth Promotion, Centers for Disese Control nd Prevention, Atlnt, GA. FUNDING/SUPPORT: The uthor hs reported to CHEST tht no funding ws received for this study. CORRESPONDENCE TO: Erl S. Ford, MD, MPH, Centers for Disese Control nd Prevention, 4770 Buford Hwy, MS F78, Atlnt, GA 30341; e-mil: eford@cdc.gov 2015 AMERICAN COLLEGE OF CHEST PHYSICIANS. Reproduction of this rticle is prohibited without written permission from the Americn College of Chest Physicins. See online for more detils. DOI: 10.1378/chest.14-2311 962 Originl Reserch [ 148 # 4 CHEST OCTOBER 2015 ]
COPD is mjor source of morbidity nd mortlity interntionlly. 1,2 In 1997, COPD ws predicted to become the third leding cuse of globl deth by 2020, 3 but subsequent nlysis found tht COPD hd become the third leding cuse of globl deth by 2010. 2 In the United Sttes, deths from chronic lower respirtory diseses, of which COPD comprises the bulk, rose to become the third leding cuse of deth in 2008. 4 In interntionl comprisons, mortlity from COPD in the United Sttes rnks high 5 ; therefore, understnding trends in COPD mortlity is of utmost importnce in formulting pproprite public helth inititives to ese the burden of this disese. A recent report showed tht ge-djusted mortlity from COPD declined substntilly from 1994 to 2010 in the Europen Community nd in most countries. 6 In comprison, the ge-djusted mortlity from COPD in the United Sttes generlly rose from 1970 to 2000 nd then leveled off fterwrd. 7-11 To provide more detiled insights into the trend of the COPD mortlity rte in the United Sttes, ntionl vitl sttistics dt from 1968 to 2011 mong dults ged 25 yers were exmined. Mterils nd Methods Mortlity dt for dults ged 25 yers were obtined from the WONDER (Wide-rnging Online Dt for Epidemiologic Reserch) system developed nd mintined by the Centers for Disese Control nd Prevention. 12 WONDER is n interctive web-bsed tool built with dt from the Ntionl Vitl Sttistics System. Institutionl review bord pprovl ws not required for this nlysis of publiclly vilble dt. Deths with COPD s the underlying cuse of deth were tbulted by using the Eighth Revision, Interntionl Clssifiction of Diseses, Adpted for Use in the United Sttes (ICD-8), codes 490, 491, 492, nd 519.3 (introduced in 1969) from 1968 to 1978; Interntionl Clssifiction of Diseses, Ninth Revision (ICD-9) codes 490 to 492; ICD-9 code 496 from 1979 to 1998; nd Interntionl Clssifiction of Diseses, 10th Revision (ICD-10) codes J40 to J44 from 1999 to 2011. Popultion estimtes produced by the Bureu of the Census in collbortion with the Ntionl Center for Helth Sttistics provided the denomintors needed to clculte rtes for ech yer. Age djustment ws done using the direct method to the projected yer 2000 US popultion. Age-djusted rtes using the following ge-groups were generted for ll dults ged 25 yers, men, women, whites, blcks, other rces, sex by rce groups, nd ge-specific rtes: 25 to 34, 35 to 44, 45 to 54, 55 to 64, 65 to 74, 75 to 84, nd 85 yers. Trends were nlyzed using the Joinpoint version 4.1.0 sttisticl progrm. 13 This progrm identifies yers when the estimted nnul percentge chnge (APC) in the mortlity rte occurs by performing Monte Crlo permuttion test nd proceeds to fit the simplest model with the fewest number of trend segments. 14 The APC is clculted s APC i 5 [(Exp(b i ) 2 1)] 3 100, where b i represents the slope of the period segment. 15 As mny s five trend segments were llowed, nd mortlity rtes were log-trnsformed. Differences in the slopes for djcent trend segments were tested with t tests. Results Overll, the ge-djusted COPD mortlity rte rose stedily from 29.4 per 100,000 popultion in 1968 to 67.0 per 100,000 popultion in 1999 nd then declined grdully to 63.7 per 100,000 popultion in 2011 ( Fig 1 ). The APC ws 3.0% (95% CI, 2.7-3.4) from 1968 to 1987, 1.9% (95% CI, 1.4-2.3) from 1987 to 2000, nd 20.2% (95% CI, 20.6 to 0.2) from 2000 to 2011 ( Tble 1 ). Thus, there ws decelertion in the ge-djusted mortlity rte during successive periods. The slope for the two ltter periods ws significntly different from tht of ech preceding period. The mortlity rte in 2011 (63.7 per 100,000 popultion) ws 5.0% lower thn in 1999 (67.0 per 100,000 popultion). Among men, the mortlity rte from 1968 (56.4 per 100,000 popultion) to its pek in 1999 (88.2 per 100,000 popultion) incresed by bout 60% nd then decresed by 16.6% by 2011 (73.5 per 100,000 popultion). The APC incresed by 2.1% (95% CI, 1.8-2.4) per yer from 1968 to 1985, chnged little from 1985 to 1999 (0.1%; 95% CI, 2 0.2 to 0.5), nd decresed by 21.1% (95% CI, 2 1.4 to 2 0.7) per yer from 1999 to 2011 ( Tble 1 ). Among women, the ge-djusted mortlity rte from 1968 (9.4 per 100,000 popultion) to its pek in 2008 (59.1 per 100,000 popultion) incresed by 530%. The APC decresed progressively in three successive periods: 7.1% (95% CI, 6.6-7.5) from 1968 to 1988, 3.7% (95% CI, 3.2-4.3) from 1988 to 2000, nd 0.4% (95% CI, 0.0-0.9) from 2000 to 2011 ( Tble 1 ). Nevertheless, the APC in the ltter period ws positive nd significnt, indicting tht rtes my still be rising mong women. Rtes in 1968 were pproximtely sixfold higher in men thn in women, but the gp between men nd women nrrowed substntilly so tht by 2008, the rte in men ws only 1.3 times higher thn in women. The sex difference in rtes reched mximum of 54.4 per 100,000 popultion in 1976 nd declined to 16.2 per 100,000 popultion in 2011. The ge-djusted mortlity rtes for blcks, whites, nd dults of rce other thn blck nd white peked in 1999, 2008, nd 1999, respectively, nd were from 3.1% to 19.2% lower in 2011 ( Fig 2 ). Only mong dults of rce other thn blck or white did the APC decrese significntly from 1999 to 2011 ( Tble 1 ). The rtio of journl.publictions.chestnet.org 963
Figure 1 Age-djusted COPD mortlity rte mong US dults ged 25 y, United Sttes 1968 to 2011. ICD8 5 Eighth Revision, Interntionl Clssifiction of Diseses, Adpted for Use in the United Sttes; ICD9 5 Interntionl Clssifiction of Diseses, Ninth Revision; ICD10 5 Interntionl Clssifiction of Diseses, 10th Revision. rtes in whites to blcks rnged from 1.5 to 1.8 nd did not vry gretly during the study period, but the bsolute difference in ge-djusted rtes incresed from 12.8 per 100,000 popultion in 1970 to 27.3 per 100,000 popultion in 2008. The ge-djusted mortlity rtes mong white nd blck men peked in 1999, nd the rte of men of rce other thn blck nd white peked in 2000. The mortlity rtes mong white nd blck women peked in 2008, nd the rte of women of rce other thn blck nd white peked in 1999. The ge-djusted rtes in whites were substntilly higher thn those in blcks nd dults of rce other thn blck nd white ( Fig 3 ). From 1999 to 2011, significnt decreses in the APC were present mong blck men, white men, nd men of rces other thn blck nd white ( Tble 1 ). In contrst, significnt increses in the APC were noted mong blck nd white women. Among women, the white to blck rtio fluctuted between 1.7 nd 2.3, with no cler trend. In contrst, the white to blck rtio mong men decresed from 1.8 in 1968 to between 1.2 nd 1.3 in 1988 nd beyond. The bsolute difference between white nd blck women incresed from 4.4 per 100,000 popultion in 1968 to 31.1 per 100,000 popultion in 2003, remining high in subsequent yers. In contrst, the bsolute difference in rtes between white nd blck men nrrowed from high of 31.4 per 100,000 popultion in 1975 to 15.6 per 100,000 popultion in 2005. The ge-specific mortlity rtes showed powerful grdient: The rte mong dults ged 85 yers ws s much s pproximtely 6,000-fold higher thn mong dults ged 25 to 34 yers nd s much s 700-fold higher thn mong dults ged 35 to 44 yers ( Figs 4, 5 ). The gespecific rtes mong dults ged 25 to 34 yers, 35 to 44 yers, 45 to 54 yers, nd 55 to 64 yers were t their peks in 1969, 1969, 1971, nd 1993, respectively, nd t their lows in 1992, 1990, 1998, nd 2006, respectively. In the three youngest ge-groups, rtes in 2011 were pproximtely 50% higher thn the ones t their ndir. In the older ge-groups, the pttern ws reversed: The lowest rtes mong dults ged 65 to 74 yers, 75 to 84 yers, nd 85 yers occurred during 1968, 1968, nd 1970, respectively, wheres the highest rtes occurred during 1999, 2008, nd 2008, respectively. The APC decresed significntly mong dults ged 35 to 44 yers since 2002, 55 to 64 yers since 1989, nd 65 to 74 yers since 1999 but incresed mong those ged 25 to 34 yers since 1983, 45 to 54 yers since 1998, nd 85 yers since 2001 ( Tble 1 ). Discussion The findings from this study document chnges in the COPD mortlity rte mong US dults ged 25 yers 964 Originl Reserch [ 148 # 4 CHEST OCTOBER 2015 ]
TABLE 1 ] APC of Age-Adjusted nd Age-Specific COPD Mortlity Rtes Among US Adults Aged 25 y, 1968 to 2011 Period 1 Period 2 Period 3 Period 4 Period 5 Group Period APC Period APC Period APC Period APC Period APC Totl 1968-1987 3.0 (2.7 to 3.4) 1987-2000 1.9 (1.4 to 2.3) b 2000-2011 2 0.2 ( 2 0.6 to 0.2) b Women 1968-1988 7.1 (6.6 to 7.5) 1988-2000 3.7 (3.2 to 4.3) b 2000-2011 0.4 (0.0 to 0.9) b Men 1968-1985 2.1 (1.8 to 2.4) 1985-1999 0.1 ( 2 0.2 to 0.5) b 1999-2011 2 1.1 ( 2 1.4 to 2 0.7) b Blcks 1968-1982 2.7 (2.0 to 3.4) 1982-1985 8.5 ( 2 2.9 to 21.4) 1985-1999 1.9 (1.4 to 2.4) 1999-2011 2 0.3 ( 2 0.8 to 0.1) b...... Other 1968-1978 2.2 ( 2 0.2 to 4.6) 1978-1981 2 9.7 ( 2 30.4 to 17.1) 1981-1984 12.8 ( 2 9.4 to 40.5) 1984-1999 1.3 (0.6 to 2.0) 1999-2011 2 1.6 ( 2 2.1 to 2 1.0) b White 1968-1986 3.1 (2.7 to 3.5) 1986-2000 2.0 (1.6 to 2.4) b 2000-2011 2 0.1 ( 2 0.5 to 0.4) b Blck women 1968-1989 6.8 (6.2 to 7.4) 1989-1999 4.3 (3.2 to 5.4) b 1999-2011 1.1 (0.5 to 1.6) b Other women 1968-1999 3.4 (2.9 to 4.0) 1999-2011 2 0.6 ( 2 1.4 to 0.2) b...... White women 1968-1988 7.2 (6.7 to 7.6) 1988-2000 3.8 (3.3 to 4.4) b 2000-2011 0.6 (0.2 to 1.0) b Blck men 1968-1988 3.5 (3.1 to 3.9) 1988-1999 0.7 (0.0 to 1.5) b 1999-2011 2 1.5 ( 2 2.1 to 2 1.0) b Other men 1968-1999 1.3 (0.9 to 1.7) 1999-2011 2 2.2 ( 2 3.0 to 2 1.5) b...... White men 1968-1985 2.1 (1.7 to 2.4) 1985-1999 0.1 ( 2 0.3 to 0.4) b 1999-2011 2 0.9 ( 2 1.3 to 2 0.6) b Age-group 25-34 y 1968-1983 2 7.7 ( 2 9.1 to 2 6.3) 1983-2011 1.0 (0.3 to 1.6) b...... 35-44 y 1968-1970 3.7 ( 2 7.8 to 16.6) 1970-1983 2 6.6 ( 2 7.4 to 2 5.8) 1983-1995 2 0.8 ( 2 1.8 to 0.2) b 1995-2002 7.3 (5.1 to 9.5) b 2002-2011 2 1.6 ( 2 2.6 to 2 0.5) b 45-54 y 1968-1998 2 1.5 ( 2 1.7 to 2 1.3) 1998-2011 2.9 (2.4 to 3.4) b...... 55-64 y 1968-1981 0.1 ( 2 0.4 to 0.7) 1981-1989 1.9 (0.7 to 3.2) b 1989-2011 2 1.0 ( 2 1.2 to 2 0.8) b (Continued) journl.publictions.chestnet.org 965
TABLE 1 ] (continued) Period 1 Period 2 Period 3 Period 4 Period 5 Group Period APC Period APC Period APC Period APC Period APC 1985-1999 1.2 (0.9 to 1.6) b 1999-2011 2 1.2 ( 2 1.6 to 2 0.9) b 65-74 y 1968-1985 2.5 (2.2 to 2.8) 1986-1999 2.2 (1.8 to 2.6) b 1999-2011 2 0.1 ( 2 0.4 to 0.3) b 75-84 y 1968-1986 4.3 (4.0 to 4.7) 1985-2001 4.1 (3.7 to 4.6) b 2001-2011 0.6 (0.1 to 1.1) b 85 y 1968-1985 5.8 (5.0 to 6.6) Dt re presented s % (95% CI). APC 5 nnul percentge chnge. P,.05 for APC. b Slope is significntly different from slope of preceding trend segment. over 44-yer period nd illustrte severl points. First, rtes re no longer rising in ll dults. Since 1999, the APC hs decresed significntly in men but is still rising, lbeit t much slower rte, in women. Second, rtes in men continue to exceed those in women, but there hs been substntil nrrowing of the sex gp. Third, rtes in whites re greter thn those in blcks, nd the difference in bsolute rtes between the two groups hs widened, driven by the divergence in rtes mong white nd blck women. Finlly, the trend ptterns differed mrkedly mong the ge-groups. Severl publictions hve described chnges in mortlity from COPD in Europe, Austrli, nd Jpn. 5,6,16 In the Europen Union, the ge-djusted rtes of mortlity from COPD mong dults ged 40 yers from 1994 to 2010 declined continuously in men, with reltively stble rtes seen in women. 6 However, the rte ggregted over 27 countries msked considerble vrition mong countries. The pttern in the United Sttes ws similr to tht in Sweden where the rte in men peked round 2000 before declining nd the rte in women continued to increse but t slower pce during the til end of the study period. In Austrli, the ge-djusted rte in men ged 55 yers incresed shrply from 1965 to 1970 nd strted continuous decline therefter tht ws prticulrly steep from 1988 to 2006. 5 In women, however, the ge-djusted rte incresed from 1965 to 1997 before strting moderte decline. In Jpn, the ge-djusted rte of mortlity from COPD in dults ged 40 yers decresed from 71.3 per 100,000 popultion in 1950 to 19.7 per 100,000 popultion in 2004 in men nd from 41.7 to 4.3 per 100,000 popultion in women. 16 Th e current nlysis shows tht the mortlity rte mong men continues to exceed tht in women. A previous nlysis of mortlity dt from 1968 to 1999 in the United Sttes reported nrrowing of the sex gp in mortlity rtes. 8 The current nlysis shows further nrrowing of this gp through 2011. Ntionl dt show interesting sex differences in COPD sttistics. Men hve higher mortlity rtes nd higher prevlence of obstructive lung function thn women, yet women re more likely to report hving COPD in surveys. 7,11,17,18 Despite substntil declines in the prevlence of smoking in the United Sttes since 1965, 19 mortlity from COPD hs remined intrctbly high, reflecting the lingering burden of tobcco use from decdes pst nd the long lg period between tobcco use nd its effect on mortlity. 966 Originl Reserch [ 148 # 4 CHEST OCTOBER 2015 ]
Figure 2 Age-djusted COPD mortlity rte mong US dults ged 25 y by rce, United Sttes 1968 to 2011. See Figure 1 legend for expnsion of bbrevitions. The declining rte in men since 1999 is welcome development, nd given the continuing decline in tobcco use, further declines in the mortlity rte in men cn be nticipted. There is lso suggestion in the dt tht the increse in COPD mortlity in women my be leveling off, but dditionl dt re required to ber this contention out. Furthermore, the ge-specific rtes in dults ged, 65 yers suggest tht future declines in the Figure 3 Age-djusted COPD mortlity rte mong US dults ged 25 y by rce nd sex, United Sttes 1968 to 2011. See Figure 1 legend for expnsion of bbrevitions. journl.publictions.chestnet.org 967
Figure 4 Age-specific COPD mortlity rte mong US dults ged 25 y, United Sttes 1968 to 2011. A, 25-34 y. B, 35-44 y. C, 45-54 y. D, 55-64 y. E, 65-74 y. F, 75 y. See Figure 1 legend for expnsion of bbrevitions. rte of COPD mortlity re likely. However, it should be noted tht the yer when the rtes reched minimum generlly occurred during the 1990s (2006 for dults ged 55-64 yers), nd the rtes mong dults ged 25 to 34 yers nd 45 to 54 yers hve incresed significntly since reching their ndirs. Thus, the mortlity rte in these ge-groups should continue to be crefully monitored. Resons for these pprent increses 968 Originl Reserch [ 148 # 4 CHEST OCTOBER 2015 ]
Figure 5 Age-specific COPD mortlity rte mong US dults ged 25 y grphed on log-scle, United Sttes 1968 to 2011. See Figure 1 legend for expnsion of bbrevitions. re uncler becuse the prevlence of current smokers hs been declining in ll ge-groups s well s in the 1960 nd 1980 birth cohorts, lthough the downturn for the ltter cohort strted only bout 1 decde go. 20 Becuse tobcco use is the single biggest contributor to the development of COPD, 20 continued public helth efforts to prevent the initition of tobcco use nd smoking cesstion mong those who continue to smoke re needed to further lower the prevlence of tobcco use. Although the prevlence of cigrette smoking mong US dults ws 19.0% in 2011, considerble interstte vrition in the prevlence in 2012 existed, with rnge of 10.6% to 28.6%. 21 These estimtes suggest tht substntil dvnces in reducing the prevlence of current smoking re fesible. Severl limittions of the present nlysis merit considertion. First, the vlidity of COPD codes on deth certifictes is unknown. A few studies in the United Sttes suggest tht deth from COPD is underreported on deth certifictes. 22,23 Second, the study period covered severl Interntionl Clssifiction of Diseses trnsitions, rising the prospect of brupt rtificil chnges in mortlity rtes. The comprbility rtio for Interntionl Clssifiction of Diseses codes 490 nd 491 in ICD-8 nd ICD-9 ws 0.9383, wheres the comprbility rtio for code 492 ws 0.9770. 24 The comprbility rtio for the ctegory chronic lower respirtory disese for the trnsition from ICD-9 to ICD-10 ws 1.0478. 25 Third, this study, like mny other mortlity studies, exmined only COPD s the underlying cuse of deth. Studies using multiple cuses of deth provide fuller picture of the burden ssocited with COPD. Finlly, seprting out people of Hispnic heritge ws not possible for the entire study period. In conclusion, the ge-djusted COPD mortlity rte peked in 1999 nd hs decresed nonsignificntly since, reflecting significnt decline in men nd significnt increse mong women. Men continue to die t higher rtes thn women, lthough the sex gp hs nrrowed, nd whites die t higher rtes thn blcks, with widening mortlity gp. Although it continues to be sserted tht mortlity from COPD hs been rising, the findings from the present study mke cler tht the COPD mortlity rte mong US dults hs stopped rising nd hs even strted to decline in some demogrphic groups. journl.publictions.chestnet.org 969
Acknowledgments Author contributions: E. S. F. hd full ccess to ll of the dt in the study nd tkes responsibility for the integrity of the dt nd the ccurcy of the nlysis, including nd especilly ny dverse effects. E. S. F. contributed to the study concept nd design; dt cquisition, nlysis, nd interprettion; nd mnuscript preprtion. Conflict of interest: None declred. Other contributions : The work ws performed t the Centers for Disese Control nd Prevention. The findings nd conclusions in this rticle re those of the uthor nd do not necessrily represent the officil position of the Centers for Disese Control nd Prevention. References 1. World Helth Orgniztion. Globl Surveillnce, Prevention nd Control of Chronic Respirtory Diseses. Genev, Switzerlnd : World Helth Orgniztion ; 2007. 2. Lozno R, Nghvi M, Foremn K, et l. 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Ntl Vitl Stt Rep. 2001 ;49(2):1-32. 970 Originl Reserch [ 148 # 4 CHEST OCTOBER 2015 ]