Arthritis in the Canadian Aboriginal population: north-south differences in prevalence and correlates*

Transcription

1 Arthritis in the Cndin Aoriginl popultion: north-south differences in prevlence nd correltes* C. Ng, MSc (1); S. Chtwood, MSc (2,3); T. K. Young, MD, PhD (3) * This rticle is prt of joint puliction inititive etween Preventing Chronic Disese nd Chronic Diseses in Cnd. Preventing Chronic Disese is the secondry pulisher, while Chronic Diseses in Cnd is the primry pulisher. Astrct Bckground: Informtion on rthritis nd other musculoskeletl disorders mong Aoriginl people is sprse. Survey dt show tht rthritis nd rheumtism re mong the most commonly reported chronic conditions nd their prevlence is higher thn mong non-aoriginl people. Ojective: To descrie the urden of rthritis mong Aoriginl people in northern Cnd nd demonstrte the pulic helth significnce nd socil impct of the disese. Methods: Using cross-sectionl dt from more thn Aoriginl people ged 15 yers nd over who prticipted in the Aoriginl Peoples Survey 2006, we ssessed regionl differences in the prevlence of rthritis nd its ssocition with other risk fctors, co-moridity nd helth cre use. Results: The prevlence of rthritis in the three northern territories ( North ) is 12.7% compred to 20.1% in the provinces ( South ) nd is higher mong femles thn mles in oth the North nd South. The prevlence mong Inuit is lower thn mong other Aoriginl groups. Individuls with rthritis re more likely to smoke, e oese, hve concurrent chronic diseses, nd re less likely to e employed. Aoriginl people with rthritis utilized the helth cre system more often thn those without the disese. Conclusion: Aoriginl-specific findings on rthritis nd other chronic diseses s well s recognition of regionl differences etween North nd South will enhnce progrm plnning nd help identify new priorities in helth promotion. Keywords: rthritis, Aoriginl people, Northern Cnd, Inuit, First Ntions, Métis, North Americn Indins, Aoriginl Peoples Survey Introduction Informtion on rthritis nd other musculoskeletl disorders mong Aoriginl people is sprse nd geogrphiclly limited minly to Alsk, British Columi nd Mnito. 1-3 Severl ntionl surveys the First Ntions Regionl Longitudinl Helth Survey (RHS), 4,5 the Cndin Community Helth Survey (CCHS) 6,7 nd the Aoriginl Peoples Survey (APS) 8,9 hve provided some dt on the prevlence of rthritis, rheumtism nd other musculoskeletl conditions, such s ck pin, mong dults in the Aoriginl popultion. These surveys generlly show tht rthritis nd rheumtism re mong the most commonly reported chronic conditions, tht prevlence is higher thn mong non- Aoriginl people in Cnd, nd tht prevlence is incresing; for exmple, the crude prevlence ws 15% in 1991 nd 19% in 2001 ccording to the APS, 8,9 while the ge-djusted prevlence ws 22% in 1997 nd 25% in 2002/03 ccording to the RHS. 4,5 (Note tht these surveys re not directly comprle with one nother due to the inclusion of different Aoriginl groups nd the use of different stndrd popultions in ge-djustment of rtes.) Arthritis lso contriutes to more thn hlf of the self-reported disility mong First Ntions people in Cnd. 5 Disility resulting from rthritis cn e excerted in the north of Cnd y severe wether, indequte infrstructure nd unrelile trnsporttion. Arthritis compromises the ility of Aoriginl people to pursue trditionl ctivities, such s hrvesting country foods, nd trditionl crfts. The geogrphicl isoltion of mny communities reduces ccess to specilist services. Culturl context is n dditionl dimension nd requires regionspecific directions nd rod prtnerships to pln nd implement culturlly pproprite helth services nd support systems; specific considertions include, ut re not limited to, ccess to trditionl helers nd medicines, lnguges spoken, nd the design of support services in communities. This pper descries the urden of rthritis mong Aoriginl people in Yukon, Northwest Territories nd Nunvut the three northern territories of Cnd. We ssess regionl differences in the prevlence of rthritis nd its ssocition with other risk fctors, co-moridity nd helth cre use etween these three northern territories (the North ) nd the ten provinces of southern Cnd (the South ) using dt from the recently relesed APS Author References 1. Institute of Medicl Science, University of Toronto, Toronto, Ontrio 2. Institute for Circumpolr Helth Reserch, Yellowknife, Northwest Territories 3. Dll Ln School of Pulic Helth, University of Toronto, Toronto, Ontrio Correspondence: Dr. T. Kue Young, 155 College Street, Rm 547, Toronto, Ontrio, Cnd M5T 3M7; Tel.: ; Fx: ; Emil: kue.young@utoronto.c Chronic Diseses in Cnd Vol 31, No 1, Decemer

2 Methods We used cross-sectionl dt from more thn Aoriginl respondents (offreserve First Ntions, Métis, Inuit) ged 15 yers nd over who prticipted in the APS 2006 (Tle 1). Sttistics Cnd conducted the APS s post-censl survey to collect informtion on the socil nd economic conditions of Aoriginl people living in Cnd. The APS 2006 sked respondents whether doctor, nurse or other helth professionl hd ever told them tht they hve rthritis or rheumtism. We seprtely exmined ssocitions etween rthritis nd vrious demogrphic, socioeconomic, ehviourl nd helth cre correltes for the three territories nd the 10 provinces, not to test specific etiologicl hypotheses ut to demonstrte the pulic helth significnce nd socil impct of the urden of rthritis. Oesity, defined s ody mss index (BMI) of 30 kg/m 2 or higher, nd smoking re well-estlished risk fctors for rthritis, 11,12 nd the APS 2006 sked respondents out their height, weight nd smoking experience nd hits. Arthritis is lso ssocited with reduced employment nd work limittions mong dults; 13 the APS sked respondents, Lst week, did you work for py or in self-employment? We determined prevlence of rthritis for three seprte groups sed on the question Do ny of your ncestors elong to the following Aoriginl groups? (Cn check more thn one): North Americn Indin, Métis or Inuit. Individuls who checked only North Americn Indin constitute the First Ntions group, individuls who checked only Inuit constitute the Inuit group, nd ll others including Métis nd those who checked multiple Aoriginl groups were comined into n Other ctegory s ech of these groups hve smll smple sizes in the North. We report only crude prevlence proportions; we did not compute gedjusted prevlence s the dtset did not include non-aoriginl people for comprison, nd compring this study with Tle 1 Numer of respondents ged 15 yers nd over y geogrphic region nd Aoriginl group in the North nd South of Cnd North South pulished ge-djusted rtes is difficult due to the different stndrd popu ltions tht hve een used; further, the crude prevlence more ccurtely reflects the urden of disese needed to pln pulic helth progrms. We performed ll nlyses using SAS version 9.2 (SAS Institute Inc, Cry, North Crolin). Since the APS 2006 ws sed on complex survey design, we used survey weights in ll nlyses nd clculted vrince estimtes using the ootstrp technique with the 1000 ootstrp weights provided y Sttistics Cnd. We determined ll proportions in ccordnce with rounding guidelines suggested y Sttistics Cnd nd clculted confidence intervls (CIs) from unrounded components. Detiled survey methodology is ville from Sttistics Cnd. 10 We used ge- nd sex-djusted logistic regression nlyses to ssess ssocitions etween rthritis nd vrious correltes. Results Prevlence Mle Femle Mle Femle First Ntions Inuit Other c Note: numers re unweighted nd hve een rounded to the nerest ten. The three Cndin northern territories: Yukon, Northwest Territories, Nunvut. The 10 Cndin provinces: British Columi, Alert, Ssktchewn, Mnito, Ontrio, Queec, New Brunswick, Prince Edwrd Islnd, Nov Scoti, Newfoundlnd nd Lrdor. c Respondents of Métis or multiple Aoriginl ncestry. The crude prevlence of rthritis or rheumtism for the three comined Aoriginl groups in the territories is 12.7% (95% CI: ) compred to 20.1% in the provinces (95% CI: ). Arthritis is more prevlent mong femles thn mles in oth the North nd South. The prevlence mong Inuit is lower thn mong First Ntions nd other Aoriginl groups. As expected, prevlence increses with ge (Tle 2). Helth risks For comprison of the proportion of respondents with nd without rthritis who re dily smokers, re oese or hve co-morid conditions, see Tle 3. Smoking is more prevlent mong Aoriginl people in the North thn in the South. In the South, there is n ssocition etween dily smoking nd rthritis (ge-sexdjusted odds rtio [OR] = 1.58, 95% CI: ), ut dily smoking is not significnt fctor in the North (OR = 1.05, 95% CI: ). Oesity is more prevlent mong individuls with rthritis, nd the ssocition etween oesity nd rthritis is stronger mong Aoriginl people in the South (OR = 1.59, 95% CI: ) thn in the North (OR = 1.36, 95% CI: ). In oth the South nd the North, higher proportion of individuls with rthritis thn those without report hving t lest one other chronic condition such s dietes, hert disese, hypertension, stroke, sthm, chronic ronchitis, emphysem or cncer (for the North, OR = 1.88, 95% CI: ; for the South, OR = 2.55, 95% CI: ). Helth cre use The proportion of individuls who report consulting helth professionl (primry cre physicin or nurse) or trditionl In the APS 2006, trditionl heler refers to someone who is recognized y the community s trditionl counsellor, or someone who provides trditionl medicines such s hers, or is trditionl or spiritul leder. 23 Vol 31, No 1, Decemer 2010 Chronic Diseses in Cnd

3 Tle 2 Crude prevlence (%) of rthritis nd rheumtism mong Aoriginl people ged 15 yers nd over in the North nd South of Cnd North South Mle Femle Both Mle Femle Both All Aoriginl groups 10.2 ( ) 15.2 ( ) 12.7 ( ) 16.2 ( ) 23.3 ( ) 20.1 ( ) First Ntions 12.0 ( ) 16.0 ( ) 14.2 ( ) 14.9 ( ) 23.2 ( ) 19.6 ( ) Inuit 8.8 ( ) 14.5 ( ) 11.7 ( ) 9.7 ( ) 18.3 ( ) 14.0 ( ) Other 10.7 ( ) 15.4 ( ) 12.9 ( ) 18.0 ( ) 23.5 ( ) 21.0 ( ) yers 1.8 ( ) 2.6 ( ) 2.2 ( ) 3.0 ( ) 4.5 ( ) 3.8 ( ) yers 6.7 ( ) 10.6 ( ) 8.7 ( ) 10.5 ( ) 15.0 ( ) 13.1 ( ) yers 20.9 ( ) 29.5 ( ) 25.3 ( ) 29.0 ( ) 40.0 ( ) 35.0 ( ) 65+ yers 34.4 ( ) 51.8 ( ) 43.5 ( ) 40.1 ( ) 60.8 ( ) 51.8 ( ) Arevitions: CI, confidence intervl. The three Cndin northern territories: Yukon, Northwest Territories, Nunvut. The 10 Cndin provinces: British Columi, Alert, Ssktchewn, Mnito, Ontrio, Queec, New Brunswick, Prince Edwrd Islnd, Nov Scoti, Newfoundlnd nd Lrdor. Tle 3 Crude prevlence (%) of helth risks ssocited with rthritis mong Aoriginl people ged 15 yers nd over in the North nd South of Cnd North South Arthritis No Arthritis Arthritis No Arthritis Dily smoking 44.8 ( ) 51.6 ( ) 36.2 ( ) 29.6 ( ) Oese (BMI 30) 36.7 ( ) 23.7 ( ) 33.4 ( ) 22.6 ( ) Co-morid conditions c 47.0 ( ) 20.4 ( ) 61.6 ( ) 29.1 ( ) Arevitions: BMI, ody mss index; CI, confidence intervl. The three Cndin northern territories: Yukon, Northwest Territories, Nunvut. The 10 Cndin provinces: British Columi, Alert, Ssktchewn, Mnito, Ontrio, Queec, New Brunswick, Prince Edwrd Islnd, Nov Scoti, Newfoundlnd nd Lrdor. c Co-morid conditions include dietes, hypertension, hert disese, sthm, chronic ronchitis, emphysem, cncer nd stroke. Figure 1 Utiliztion of helth services y Aoriginl people ged 15 yers nd over in the North nd South of Cnd y type of provider nd y rthritis sttus Percent of respondents ( ) South 31.4 ( ) 6.7 ( ) 67.6 ( ) 26.9 ( ) 4.4 ( ) 79.0 ( ) 71.0 ( ) North 9.6 ( ) 52.3 ( ) 62.3 ( ) 5.8 ( ) Arthritis No Arthritis Arthritis No Arthritis Consulted MD Consulted nurse Consulted trditionl heler The three Cndin northern territories: Yukon, Northwest Territories, Nunvut. The 10 Cndin provinces: British Columi, Alert, Ssktchewn, Mnito, Ontrio, Queec, New Brunswick, Prince Edwrd Islnd, Nov Scoti, Newfoundlnd nd Lrdor. Chronic Diseses in Cnd Vol 31, No 1, Decemer

4 heler nytime in the 12 months preceding the survey ws higher mong individuls with rthritis thn those without the condition. (In the North, OR = 2.32, 95% CI: ; in the South, OR = 2.25, 95% CI: ). In the North, rthritis ptients consulted nurses nd trditionl helers more nd physicins less frequently thn those in the South. (See Figure 1.) Socil conditions A lower proportion of individuls with rthritis report eing employed in the week efore the survey (either self-employed or otherwise working for py) compred to those without rthritis. The ssocition ws stronger in the South (OR = 0.58, 95% CI: ) thn in the North (OR = 0.75, 95% CI: ). Discussion The lower prevlence estimtes mong Aoriginl people in the North compred to those in the South otined from the APS 2006 re comprle to those from other surveys. 6,7 In Tjepkem s nlyses of CCHS 2000/01, 6 the prevlence for Aoriginl people in the North is 10% while tht in the South is 19% for rurl residents nd 20% for urn residents; Lix et l. otin prevlence of 12% in the North nd 20% in the South from the CCHS 2005/06. 7 Both these studies lso show tht the prevlence mong Aoriginl people is higher thn non-aoriginl people in the South ut not in the North. Note tht oth the CCHS nd APS cover the sme Aoriginl groups off-reserve First Ntions, Inuit nd Métis. Although less ccess to specilist cre my e responsile for the lower detection rte of rthritis in the North, the prevlence of rthritis is sed on self-report nd not on cliniclly verified dignoses y rheumtologists; further, s chronic disese rthritis is likely to hve een dignosed sometime in the pst over the long term even with limited specilist helth cre. In surveys such s the APS, CCHS nd RHS, self-reports under the ruric rthritis nd rheumtism lck clinicl ccurcy. These self-reports re lso limited y the inility to differentite etween different types of rthritides rheumtoid rthritis, osteorthritis, etc. However, s tool for ssessing popultion helth nd the need for helth cre, such crude mesures re nevertheless useful, prticulrly to descrie the ptterns in different popultion sugroups. The lower prevlence of rthritis mong Aoriginl people in the North cn lso e ttriuted to the high proportion of Inuit in the popultion. (According to the 2006 Census, pproximtely 54% of Aoriginl residents of the northern territories report some Inuit ncestry, compred to 4% of Aoriginl people in Cnd s whole. 14 ) A lower prevlence of rthritis mong Inuit reltive to other Aoriginl people hs een shown ntionlly in APS nd CCHS 2000/01. 6 In this study we demonstrte tht, within the North, the prevlence of rthritis mong ll Aoriginl groups Inuit, First Ntions, nd Other is lso lower thn the corresponding group in the South (Tle 2). It is uncler s to why Cndin Inuit hve lower prevlence of rthritis thn First Ntions people. The self-reported rthritis ruric is mixed g of clinicl entities with different etiologies. A review of North Americn indigenous popultions found tht Inuit tend to hve high rtes of spondylorthropthies wheres Ntive Americns hve high rtes of rheumtoid rthritis. 1 A study sed on clinicl records indictes tht the Inupit in the Alsk North Slope region (who re culturlly nd linguisticlly relted to the Inuviluit in the Northwest Territories) hve high rtes of rheumtoid rthritis compred to some Ntive Americn tries, nd much higher thn the Yupik in western Alsk. 15 A recent study from Alsk tht estimted the prevlence of self-reported nd cliniclly undifferentited rthritis showed tht it is higher mong Alsk Ntives thn the generl U.S. popultion, ut the Alskn smple is mix of Yupik nd Ntive Americn tries in the southestern prt of the stte. 16 Aoriginl people suffering from rthritis hve unfvourle helth profiles; they re more likely to e dily smokers, e oese nd hve concurrent chronic diseses, lthough the mgnitude differs etween the North nd South, reflecting the ckground prevlence of these ssocited trits nd conditions. Arthritis cn limit the opportunity for employment, lthough this survey does not provide evidence tht the lower employment rte is the direct result of the disese. As expected, Aoriginl people with rthritis re more likely to utilize the helth cre system, with higher proportions reporting visits to physicins, nurses nd trditionl helers. The pttern of use reflects the different systems in plce in the North nd South. We cnnot, however, determine if the higher helth service use is the direct result of rthritis, ut it is plusile explntion given the nture of the disese, the presence of other risk fctors such s smoking nd oesity, nd co-moridities. In the North, primry cre is predominntly delivered y nurses in helth centres in the communities, nd individuls hve only periodic contct with visiting physicins. For mny, visits to specilists such s rheumtologists requires ir trvel wy from home. Further reserch is required to explore North-South disprities in the urden of rthritis in Aoriginl popultions. Also needed re more refined dignoses, including rheumtoid rthritis, osteorthritis nd other musculoskeletl disorders, s well s seprte nlyses of Inuit nd First Ntions smples, which re sufficiently lrge within the North. Aoriginl-specific findings on rthritis nd other chronic diseses, s well s recognition of regionl differences etween North nd South, will enhnce progrm plnning nd help identify new priorities in helth promotion. The cretion nd trnsmission of qulity evidence to pproprite stkeholders to ensure uptke nd ppliction of study findings will help reduce helth disprities. Acknowledgment Funding for this study ws provided y the Cndin Arthritis Network s Ntionl Aoriginl Arthritis Reserch Inititive (project code: 07-NAARI-04). 25 Vol 31, No 1, Decemer 2010 Chronic Diseses in Cnd

5 References 1. Peschken CA, Esdile JM. Rheumtic diseses in North Americ s indigenous peoples. Semin Arthritis Rheum. 1999;28: O Donnell V, Tit H. Aoriginl Peoples Survey initil findings: well-eing of the non-reserve Aoriginl Popultion. Ottw (ON): Sttistics Cnd; 2003 [Sttistics Cnd, Ctlogue No.: XIE]. 2. Brne C, Elis B, Brtlett J, Roos L, Peschken C. Arthritis in Aoriginl Mnitons: evidence for high urden of disese. J Rheumtol. 2008;35: Ferucci ED, Templin DW, Lnier AP. Rheumtoid rthritis in Americn Indins nd Alsk Ntives: review of the literture. Semin Arthritis Rheum. 2005;34: Young TK, O Neil JD, Elis B, Leder A, Reding J, McDonld G. Chpter 3: Chronic diseses. In: First Ntions nd Inuit Regionl Helth Survey Finl Report [Internet]. McMilln H, Wlsh C, Jmieson E, Crwford A, Boyle M, Editors. Ottw (ON): First Ntions nd Regionl Helth Survey Ntionl Steering Committee, 1999 [cited 2010 July 5]. p Aville from: rhs_1997_finl_report.pdf 5. Assemly of First Ntions/First Ntions Informtion Governnce Committee. First Ntions Regionl Longitudinl Helth Survey (RHS) 2002/2003: results for dult, youth nd children living in First Ntions communities. Rev. 2 nd ed. Mrch 2007 [cited 2010 July 5]. Aville from: rhs-ers.c/english/pdf/rhs reports/ rhs techniclreport-fn.pdf 6. Tjepkem M. The helth of the offreserve Aoriginl popultion. Helth Rep. 2002;13 (Suppl): [Sttistics Cnd, Ctlogue No.: ]. 7. Lix LM, Bruce S, Srkr J, Young TK. Risk fctors nd chronic conditions mong Aoriginl nd non-originl popultions. Helth Rep. 2009;20: Sttistics Cnd. Aoriginl Peoples Survey, 2006: concepts nd methods guide. Ottw (ON): Sttistics Cnd; 2009 [Sttistics Cnd, Ctlogue No.: X no.003]. 11. Oliveri SA, Felson DT, Cirillo PA, Reed JI, Wlker AM. Body weight, ody mss index, nd incident symptomtic osteorthritis of the hnd, hip, nd knee. Epidemiology. 1999;10: Heliovr M, Aho K, Arom A, Knekt P, Reunnen A. Smoking nd risk of rheumtoid rthritis. J Rheumtol. 1993;20: Lcille D, Hogg RS. The effect of rthritis on working life expectncy. J Rheumtol. 2001;28: Sttistics Cnd. Aoriginl ncestry (10), re of residence (6), ge groups (12) nd sex (3) for the popultion of Cnd, provinces nd territories, 2006 Census 20% Smple. Ottw (ON): Sttistics Cnd; Dt [Sttistics Cnd, Ctlogue No.: XCB ]. 15. Boyer GS, Benevolensky LI, Templin DW, Erdesz S, Bowler A, Alexeev LI, Goring WP, Krylor MY, Mylov NM. Prevlence of rheumtoid rthritis in circumpolr ntive popultions. J Rheumtol. 1998;25: Ferucci ED, Schumcher MC, Lnier AP, Murtgh MA, Edwrds S, Helzer LJ, Tom-Orme L, Slttery ML. Arthritis prevlence nd ssocitions in Americn Indin nd Alsk Ntive people. Arthritis Rheum. 2008;59: Sttistics Cnd. Lnguge, trdition, helth, lifestyle nd socil issues: 1991 Aoriginl Peoples Survey. Ottw (ON): Sttistics Cnd; 1993 [Sttistics Cnd, Ctlogue No.: ]. Chronic Diseses in Cnd Vol 31, No 1, Decemer