Malmo, situated in the southernmost province

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1 Stroke Registry i Malmo, Swede Peter Jertorp, MD, ad Gora Berglud, MD Backgroud ad Purpose: A stroke registry coverig the city of Malmo, Swede (populatio,) was started i Jauary of 89 to prospectively follow up stroke icidece, recurrece, ad fatality rates. Methods: Patiets with presumed stroke were iterviewed withi 1 week after admissio to the hospital, ad their medical records were examied. Cotiuous validatio agaist hospital diagosis showed well over 9% of all stroke cases i Malmo to have bee icluded. Results: Icidece rates per, residets were for all stroke evets ad for first-ever stroke, lower tha those reported from other studies. The distributio of stroke diagostic categories was % subarachoid, % itracerebral, % cerebral ifarctio, ad 8% uspecified stroke. The diagosis was based o computed tomography i 1% of first-ever stroke cases. Media age was.1 for me ad 9. for wome. Icidece rates for all stroke diagostic categories except subarachoid icreased with age. Prior stroke, hypertesio, smokig, atrial fibrillatio, ad diabetes mellitus were major risk factors for all stroke evets. The presetig symptoms were hemiparesis i %, speech disorder i 9%, ad clouded cosciousess i % of the patiets. The overall case-fatality rate at days was 1%; the rate for itracerebral was % ad that for cerebral ifarctio was %. Coclusios: Our fidigs cofirm the value of a stroke registry for stroke epidemiology purposes ad as a tool for specific stroke research. (Stroke 9;:-1) KEY WORDS icidece stroke registry Swede Malmo, situated i the southermost provice of Swede, is the coutry's third largest city, with a populatio of almost a quarter of a millio ad a disproportioately high frequecy of elderly people. Twety-two percet of the ihabitats belog to the > -year-old age group, of which % are foreig immigrats. The city has the highest doctor/patiet ratio i Swede ad is served by a sigle casualty ad emergecy uit dealig with, cases aually. Malmo Geeral Hospital, with 1, beds, is the oly hospital. Cooperatio amog the departmets of iteral medicie, eurology, ad geriatrics is well established. Because patiets with acute illess traditioally come to the hospital directly, virtually all patiets with presumed stroke are examied there. This, together with the high ecropsy rate at the hospital, reders Malmo well suited for epidemiological research o stroke. The icreased attetio to stroke has bee associated with the establishmet of at least stroke registries throughout the world. 1 - Fidigs i time-tred studies have suggested that the icidece of stroke is decreasig i most areas but icreasig i others, " 8 makig recet epidemiological data from various parts of the world of great iterest. The stroke registry i Malmo (STROMA) started o Jauary 1, 89, ad was desiged to fulfill three mai fuctios: to record the icidece of stroke, both overall From the Departmet of Iteral Medicie, Lud Uiversity, Malmo Geeral Hospital, Malmo, Swede. Supported by the Aa Josso Foudatio. Address for correspodece: Peter Jertorp, MD, Departmet of Medicie, Geeral Hospital, S-1 1 Malmo, Swede. Received March 1, 91; accepted October, 91. ad cause-specific, i a large Swedish commuity; to trace chages i stroke icidece, recurrece, ad fatality rates, log-term progosis, ad risk factor patters over a -year period; ad to serve a^ a data base for use i observatioal studies ad itervetioal programs. We preset a brief accout of the results at 1 year ad the fidigs of a -18-moth follow-up of cases with regard to recurrece ad fatality rates. Subjects ad Methods Stroke was defied as rapidly developig cliical sigs of local or global loss of cerebral fuctio lastig for > hours (or leadig to death before the) with o apparet cause other tha cerebral ischemia or. 1 I this cotext, the term global refers maily to subarachoid. By defiitio, cases of trasiet ischemic attack (TIA) were excluded. Oly patiets with first-ever stroke after Jauary 1, 89, were icluded i STROMA. All recurreces were recorded, provided that the recurret evet occurred at least weeks after the precedig evet. Those patiets with a prior stroke before Jauary 1, 89, were ot icluded i STROMA but were recorded i a complemetary stroke registry. All rates quoted below refer to STROMA-89, which icluded 98 stroke evets durig the year, of which were first-ever stroke. Case fidig was the resposibility of a specially traied urse coordiator uder the supervisio of seior physicias. All cases of suspected or diagosed symptomatic stroke were actively sought by the STROMA urse, who kept a daily check o symptoms ad prelimiary diagoses recorded i the hospital ad casualty admissio registers. All cases with a diagosis such as stroke, paresis, dysphasia, dizziess, or cofu-

2 8 Stroke Vol, No March 9 sio were followed up, with about oe i five evetually beig icluded i STROMA. All 1 wards ormally admittig stroke patiets were visited by the STROMA urse 1- times a week, whe possible stroke evets were followed up. Every secod week other wards at Malmo Geeral Hospital, as well as the eurosurgery departmet at Uiversity Hospital i the earby city of Lud ad all local istitutios for the care of the elderly, were cotacted for iformatio o stroke evets i subjects livig i Malmo. Both ipatiet ad outpatiet cosultatios at the departmets of iteral medicie ad eurology, filed i cetral records by diagosis, were checked by the STROMA urse at mothly itervals. Autopsy cases for which death certificatio recorded sudde death due to stroke were also icluded i STROMA. I most cases, both the patiets themselves ad their care teams, together with the cosultig specialist(s), were iterviewed by the STROMA urse withi 1 week after a stroke evet, ad the medical records were carefully scrutiized. At iclusio i STROMA, the case iformatio was etered o a stadardized computer record form comprisig 9 items, all of which were defied i a maual. These items icluded demographic data, history of cardiovascular disease, ad details of cliical status at the oset of stroke ad at iclusio i the registry. Details of some of the more complex items are give below. Computed tomography (CT), performed withi 1 week after the stroke, was used for classificatio purposes i (1%) of the cases icluded i STROMA-89. Eighty-six percet of the CT examiatios were performed withi days after the oset of symptoms, ad the other 1% were performed - days after the oset. The mea age of the patiets examied with CT was less tha that of patiets ot udergoig CT (. ±11. versus 8. ±8.9, respectively; /?<.1). The criterio for stroke classified as subarachoid or itracerebral was verificatio of the respective cliical picture at CT, lumbar pucture, or ecropsy. Classificatio as cerebral ifarctio required a typical cliical picture ad either a typical CT sca (or a ormal CT sca whe performed withi days after oset) or the presece of a potetial source of emboli with a strog cliical reaso to suspect cerebral embolism or verificatio at ecropsy. Where oe of these criteria were fulfilled, the evet was classified as uspecified stroke. No attempts were made to itervee i the diagostic routies of the various departmets. Doppler ultrasoud or agiographic fidigs of >% steosis or ulceratio ad TIA verified from medical records were cosidered to idicate extracraial occlusive disease. Chroic or itermittet atrial fibrillatio or flutter was recorded as atrial fibrillatio. Other heart diseases listed icluded previously diagosed orgaic left vetricle defects, myocardial ifarctio, ad heart failure. Other recorded atherosclerotic maifestatios cosisted of previously diagosed agia pectoris, itermittet claudicatio, ad aeurysm of the abdomial aorta. Hypertesio was cosidered to be preset if the patiet was receivig chroic atihypertesive treatmet at the oset of the stroke. The term "smoker" was take to imply regular smokig at the oset of the stroke ad the term "exsmoker" to mea previous regular smokig for a period exceedig 1 year but termiated before the oset of the stroke. Previously diagosed ad suspected hypercholesterolemia were recorded if oe plasma cholesterol value was >. mmol/1 (> mg/dl). Hypercholesterolemia was cosidered to be ot preset if plasma values were <. mmol/1. Previously diagosed diabetes was recorded, ad blood glucose values of >. mmol/1 (>11 mg/ml) were take to idicate suspected diabetes. Diabetes was cosidered to be ot preset if blood glucose values were cosistetly <. mmol/1. The course of disease durig the first week after the stroke was classified by the care team as complete or almost complete regressio, some improvemet, deficit uchaged, progressio, or death. The course of disease was evaluated i patiets alive at admissio ad icluded i the registry withi weeks after the stroke. O July 1, 9, a -18-moth (media 1 year) follow-up was carried out o all cases with a first-ever stroke durig 89. The registry was scrutiized for cases of recurrece. The hospital register, updated weekly, was checked agaist the mortality register for all cases icluded i STROMA-89 to determie if death occurred later. This iformatio was added to STROMA. The Ma-Whitey rak sum test ad the x test were used for statistical aalysis. Probability values were two tailed, ad p<. was cosidered to be sigificat. Results are give as mea±sd. Results I 89 there were 98 stroke evets ad firstever strokes; the icideces per, residets were ad, respectively. I either case did the icidece per, differ sigificatly betwee wome ad me, beig ad, respectively, for all stroke evets ad 8 ad, respectively, for firstever stroke. Amog the first-ever stroke cases, mea±sd age was. ±.1 for wome ad 1. ±11.8 for me ad media age was 9. ad.1, respectively (p<.1 i both cases). A similar age differece betwee wome ad me was foud amog recurret stroke cases (.±8.9 ad.±9., respectively; p<.1). The age-specific icidece rates of first-ever stroke are show i Table 1. Although there was o sex-related differece i overall icidece, i all except the >8-year-old age group icidece rates were higher for me tha for wome; the differece was sigificat (p<.1) for the - ad -8-year-old age groups. The most commo type of stroke was cerebral ifarctio, accoutig for % () of the cases (Table ). The icidece rates of all types of stroke except subarachoid icreased with age. Of the patiets with first-ever stroke icluded i STROMA-89, (8%) had bee admitted to the hospital as acute cases, 1 (8%) had developed stroke while ipatiets, ad the remaiig (%) were treated as outpatiets or died before they could be admitted. Overall mortality before iclusio i STROMA-89 was 8% ( of ), the cause-specific rate beig sigificatly greater for subarachoid (%, six of 1) ad itracerebral

3 Jertorp ad Berglud Stroke Registry i Malmo 9 TABLE 1. Number of First-Ever Stroke Cases, Icidece Rates, ad Male/Female Icidece Rate Ratios i 89 by Age Group Aee eroud Populatio at risk All cases (yr) Rate Rate Rate (male/female) - :8,18 1, 1, 1,1 11,89,9,8 1,1 1,8 11,8, 1, ,1 1, ,9 1, , 1,.1..9 Total 1,8 1, Icidece rate per, populatio. is ot give for group with «<. (%, 1 of 1) tha for cerebral ifarctio (%, 1 of ) (p<.1 i both cases). The iterval betwee the stroke evet ad registratio was 1- days i 8% of the cases ad 8-1 days i %. Amog cases for which the iterval was > weeks, % of the patiets were dead at registratio; either sex, age, or diagosis differed betwee this subgroup ad those registered before the ed of the secod poststroke week. Amog all first-ever stroke cases, atrial fibrillatio was preset i %, extracraial occlusive disease i 1%, other cardiac diseases i %, other atherosclerotic maifestatios i 1%, hypertesio i %, smokig i %, diabetes i 1%, ad hypercholesterolemia i 8%. Amog first-ever stroke patiets, the absece of ay major atherosclerosis risk factor could be verified i (9%) ad the absece of cocomitat disease i (%). Patiets were usually admitted with hemiparesis ad speech disorders, ad most were coscious (Table ). Durig the first week % of cases improved, the fuctioal disability was uchaged i 18%, ad the stroke progressed i %. At follow-up o July 1, 9, of the cases icluded i STROMA-89 had suffered a recurret stroke; that is,.% of the series as a whole ad.% of the survivors had had a recurrece. The overall casefatality rate was 9% (=) at days, 1% (=9) at weeks, 1% («=8) at days, ad % ( = 1) at moths. The case-fatality rate was higher amog patiets with itracerebral tha amog those with cerebral ifarctio at both days (% versus %, respectively) ad moths (% versus 1%, respectively) after first-ever stroke (p<.1 i both cases). Amog patiets with subarachoid, the case-fatality rate was 1% at days ad 9% at moths poststroke. Discussio By traditio i Swede, the majority of stroke patiets are admitted directly to the departmets of iteral medicie or eurology via the emergecy room of the local hospital. It is customary for a umber of hospital departmets to cooperate i the care of patiets with cardiovascular disorders. Our stroke registry at Malmo, STROMA, was desiged to serve the whole commuity; geeral practitioers ad commuity-employed physicias at istitutios for the care of the elderly were iformed that stroke TABLE. Number of Cases, Icidece Rates, ad Male/Female Icidece Rate Ratio i 89 by Type of Stroke ad Age Group Type of stroke Age group (y) - St8 1 Subarachoid Rate (male/female) Itracerebral Rate (male/female) 8 1 Rate Cerebral ifarctio (male/female) Uspecified stroke Rate i(male/female) , Total % Icidece rate per, populatio. s are ot give for groups with <.

4 Stroke Vol, No March 9 TABLE. Cliical status Cosciousess Awake Somolet Comatose Hemiparesis No Yes Speech disorder No Yes Cliical Status of Stroke Patiets at Admissio Itracerebral (»=1) * Cerebral ifarctio (=) All cases (=) , item could ot be properly judged due to patiet's low level of cosciousess. Values are %. *p<.1 differet from cerebral ifarctio. patiets should be referred to Malmo Geeral Hospital. Of the cases of first-ever stroke icluded i STROMA-89, % had bee treated as outpatiets or died before admissio ad % had suffered a stroke while i istitutioal care. Our results cofirm previous reports; these categories accout for < % of all cases of first-ever stroke i Swede. 9 - Scrutiy of hospital records suggests that <% of all stroke patiets admitted to a hospital were ot icluded i STROMA. Moreover, because hospital diagostic records are ot always specific, may of the "missed" cases may have bee stroke sequelae rather tha stroke itself. Except for patiets who did ot seek medical advice ad the oldest ad most disabled patiets i istitutioal care, where mior stroke might have remaied udetected, it is reasoable to suppose that almost all cases of first-ever stroke were icluded i STROMA-89. The few possibly udetected cases would be ulikely to affect the results, except perhaps i the > 8-year-old age group. Logitudial studies of stroke icidece i Swede have show regioal differeces. I Stockholm, durig the period -81 the icidece amog me icreased steadily while that amog wome remaied stable. 11 I Soderham, the icidece amog wome icreased betwee -8 ad 8-8 while that amog me remaied stable. The icidece rates foud i the preset study ca be compared with those obtaied i previous series. 9 " 1 However, it should be bore i mid that iclusio criteria have varied amog studies, all stroke maifestatios havig bee icluded i some series, but oly first-ever stroke i others. The aual icidece of first-ever stroke per, residets was i Malmo compared with 1 i Lud-Orup, 1 9 i Soderham, ad about i Gotheburg. 9 However, figures for overall icidece are extremely depedet o the age distributio of the populatio studied; the > -year-old age group, for istace, accouted for % of the residets i Malmo i 89 compared with 1% i Gotheburg i, % i Soderham i 8, ad 1% i Lud-Orup i 8. Age-specific icidece rates i selected commuities i orther Europe are show i Table. Because the differeces i icidece rates amog ceters are oly partly ascribable to differeces i methodology, these figures suggest the existece of real geographic variatio i the risk of stroke. A oteworthy differece is that the figure for Malmo was markedly lower tha that for its immediate eighbor, the Lud-Orup district. Ideed, i all likelihood the real differece is eve greater because the Lud-Orup study was based o hospital records oly. Because that commuity is partly rural, stroke cases there are less commoly see first i the hospital tha is the case for Malmo. The relatively low icidece i Malmo may well be due to active itervetio ad prevetive measures resultig from repeated health screeig programs carried out durig the past 1 i the populatio at risk. The data collected by STROMA i the comig will clarify whether this iterpretatio is correct. Stroke classificatios were based o CT examiatios i both the preset ad the Lud-Orup studies. 1 Although the proportios of cases of subarachoid ad itracerebral i the two studies were the same, i the Lud-Orup study % of all stroke cases were classified by cliical diagosis as atherothrombotic ifarctio or cardiac embolism. I the preset study, amog stroke cases for which either CT, TABLE. Age-Specific Icidece Rates for First-Ever Stroke i Selected Commuities i Norther Europe Durig the Last Two Decades Commuity Fredriksberg, Demark Filad 1 Gotheburg, Swede 9 Tilburg, The Netherlads Lud-Orup, Swede 1 Soderham, Swede Malmo, Swede First-ever Overall* Years of study Rate per, populatio per year. 'Overall rates. < ,1 1,8 1,9 1, 9,1 8 1, 1,1 1,1, >8,9 1,, < ,1 1, 9 1,, 1, 8, 8 1, 1,9, 1,9 1,88 8, 1, 1,8

5 Jertorp ad Berglud Stroke Registry i Malmo 1 lumbar pucture, or ecropsy was performed stroke was classified as cerebral ifarctio oly whe the cliical picture was cosistet with cardiac embolism. The relatively high proportio of cases desigated as uspecified stroke is explaied by the fact that exclusio of all possibility of the presece of was the sie qua o for a diagosis of cerebral ifarctio. Age, sex, prior stroke, diabetes mellitus, hypertesio, cardiac disease, TIA, smokig, ad a high blood cholesterol cocetratio have previously bee show to be risk factors for stroke. 1-1 I the preset study, atherosclerosis risk factors or prior maifestatios of vascular disease were preset i virtually all stroke cases, suggestig that stroke is a late complicatio of arterial disease. The icidece of stroke has bee foud to be strikigly correlated to age, i both previous studies 9-1 ad the preset study, where it was times higher i the >8-year-old age group tha amog patiets aged. That prior stroke is a strog predisposig risk factor for ew stroke was bore out by the fact that % of all stroke evets registered i STROMA-89 were recurreces. Our data cofirm that atrial fibrillatio is associated with stroke amog all age groups, but especially amog the elderly. The prevalece of atrial fibrillatio i a ormal populatio was foud to be 1.% amog wome aged -9 ad % amog me aged Although the case-fatality rate was high durig the first poststroke weeks, the 1-moth rate was relatively low, 1%, compared with % i Soderham, 18% i Lud-Orup, 1 ad % i Oxfordshire. 18 The relatively low case-fatality rate i the preset study may have bee due to improvemet i the acute care of stroke patiets durig the past decade. To summarize, i all likelihood the overwhelmig majority of first-ever strokes were registered i STROMA-89. Icidece rates ad case-fatality rates were lower tha those reported from other ceters. A umber of typical stroke-associated features were cofirmed to be major risk factors. Clearly, a stroke registry is a importat tool for use i both specific stroke research ad epidemiological ivestigatios. Ackowledgmets We wish to thak Igcla Jertorp, RN, for the careful stroke registerig; Dr. Helee Pessah-Rasmusse for her eergetic work with the forms; Ragar Aim for computer programmig; ad Dr. Kjeld Hougaard, Departmet of Neurology, for costructive criticism of the paper. Refereces 1. World Health Orgaizatio: Cerebrovascular diseases: Prevetio, treatmet ad rehabilitatio. Report of a WHO meetig. WHO Tech Rep Ser 1;9. Harmse P, Tibbli G: A stroke register i Goteborg, Swede. Ada Med Scad ;1:-. Stesgaard Hase B, Marquardse J: Icidece of stroke i Fredriksberg, Demark. Stroke ;8:-. Herma B, Leyte ACM, va Luijk JH, Freker CWGM, Op de Coul AAW, Schulte BPM: Epidemiology of stroke i Tilburg, the Netherlads: The populatio-based stroke icidece register:. Icidece, iitial cliical picture ad medical care, ad three-week case fatality. Stroke 8;1:9-. Teret A: Icreasig icidece of stroke amog Swedish wome. Stroke 88;:98-. Garraway WM, Whisat JP, Furlad AJ, Philips LH, Kurlad LT, O'Fallo WM: The decliig icidece of stroke. N Egl J Med 9;:9-. Ueda K, Omae T, Hirota Y, Takeshita M, Katsuki S, Taaka K, Ejoji M: Decreasig tred i icidece ad mortality from stroke i Hisayama residets, Japa. Stroke 81;1:1-8. Kotila M: Decliig icidece ad mortality of stroke? Stroke 8;1:-9 9. Harmse P, Berglud G, Larsso O, Tibbli G, Wilhelmse L: Stroke registratio i Goteborg, Swede, -: Icidece ad fatality rates. Ada Med Scad 9;:-. Teret A: A prospective epidemiological survey of cerebrovascular disease i a Swedish commuity. Ups J Med Sci 9;8:- 11. Alfredsso L, vo Arbi M, de Faire U: Mortality from ad icidece of stroke i Stockholm. Br Med J 8;9: Norrvig B, Lowehielm P: Epidemiology of stroke i Lud-Orup, Swede, 8-8: Icidece of first stroke ad age-related chages i subtypes. Ada Neurol Scad 88;8: Reuae A, Aho K, Aromaa A, Kekt P: Icidece of stroke i a Fiish prospective populatio study. Stroke 8;1: Bamford J, Sadercock P, Deis M, Warlow C, Joes L, McPherso K, Vessey M, Fowler G, Molyeux A, Hughes T, Bur J, Wade D: A prospective study of acute cerebrovascular disease i the commuity: The Oxfordshire Commuity Stroke Project 81-8: 1. Methodology, demography ad icidet cases of first-ever stroke. / Neurol Neurosurg Psychiatry 88;1: Dyke M, Wolf P, Barett HJM, Berga J, Hass W, Kael W, Kuller L, Kurtzke J, Sudt T: Risk factors i stroke. Stroke 8;1:1-llll 1. Wolf PA, Kael WB, Verter J: Curret status of risk factors for stroke. Neurol Cli 8;l:1-1. Wolf PA, Abbott RD, Kael WB: Atrial fibrillatio: A major cotributor to stroke i the elderly: The Framigham Study. Arch Iter Med 8;1: Bamford J, Sadercock P, Deis M, Bur J, Warlow C: A prospective study of acute cerebrovascular disease i the commuity: The Oxfordshire Commuity Stroke Project 81-8:. Icidece, case fatality rates ad overall outcome at oe year of cerebral ifarctio, primary itracerebral ad subarachoid haemorrhage. J Neurol Neurosurg Psychiatry 9;:1-