RHEUMATOID ARTHRITIS PATIENTS CANNOT ACCURATELY REPORT SIGNS OF INFLAMMATORY ACTIVITY

Transcription

1 Brtsh Journal of Rheumatology 995;4: RHEUMATOID ARTHRITIS PATIENTS CANNOT ACCURATELY REPORT SIGNS OF INFLAMMATORY ACTIVITY S. E. HEWLETT, J. HAYNES, L. SHEPSTONE and J. R. KIRWAN Unversty of Brstol Rheumatology Unt, Brstol BS8HW SUMMARY If patents wth rheumatod arthrts (RA) could self-report symptoms n a manner whch correlated wth laboratory measures of nflammaton ths would be a valuable research or clncal tool. Developng such a tool means ensurng that the questons are understood and a varety of combnatons of sgns, symptoms and jonts explored. Prelmnary studes n two groups of RA out-patents establshed an acceptable self-report questonnare format by whch patents could dentfy ther jonts. Ffty RA out-patents completed these self-report forms on four grades of each of four symptoms (pan, heat, stffness, swellng) n each of 64 jonts, as well as vsual analogue scales (VAS) on overall pan and perceved dsease actvty. A clncal research assstant recorded the Thompson-Krwan artcular ndex (TKAI) and plasma vscosty (PV) was measured. The data were analysed n a varety of ways n an attempt to construct a self-report artcular ndex (SRAI) whch correlated wth PV. The strongest models were then tested n n-patents undergong a flare of ther dsease. No adequate SRAI could be constructed whch correlated wth PV and n addton nether VAS score correlated wth PV. There was a moderate correlaton between the TKAI and a patent SRAI usng the same jonts, symptoms and weghtngs (r =.6, P <.). Patents can clearly report dfferent grades of multple symptoms n multple jonts, but such reports cannot be shown to be a relable ndcator of nflammatory actvty. KEY WORDS: Rheumatod arthrts, Self-report, Inflammatory actvty, Artcular ndex, Jont count. IN rheumatod arthrts (RA) some means of assessng nflammatory actvty s necessary n order to evaluate dsease progresson, effcacy of therapy and treatment strateges. The crtera for assessng such nflammatory actvty vary, but usually nclude a combnaton of clncal assessments (e.g. examnaton of jonts for synovts and tenderness), laboratory ndces of nflammaton [e.g. C-reactve proten (CRP), plasma vscosty] and patent reports of symptoms (e.g. pan, stffness and fatgue) []. These tradtonal assessments, essental for patent management, requre the patent to make a hosptal vst for clncal examnaton and/or venepuncture. However, n some research studes (e.g. psychologcal projects) such vsts are an unnecessary nconvenence as the patent could complete self-report questonnares for the man part of the study and t s only the need for an assessment of nflammatory actvty whch demands a vst to the clncan. If patents could accurately report ther own nflammatory actvty such a requrement would be obvated. The development of a smple self-report questonnare whch reflected jont nflammaton as measured by tradtonal methods would therefore be a valuable research tool for use n studes where t was requred for research rather than management purposes. Such a non-nvasve self-report measure would save both tme and nconvenence for the patent and the researcher. Indeed t may be that patents are better able to assess ther nflammatory Submtted 6 November 994; revsed verson accepted March 995. Correspondence to: S. Hewlett, Rheumatology Unt, Brstol Royal Infrmary, Brstol BS 8HW. actvty than health care professonals and patents may also be more senstve to mnor changes n ther own feelngs and symptoms. Standardzed methods for health care professonals to assess and record jont symptoms and sgns (artcular ndces) relate to pan, tenderness, warmth and soft tssue swellng, all of whch are clncal ndcatons of jont nflammaton. Artcular ndces (AI) nclude the Rtche ndex [] (based on graded tenderness n varous jont groups), the Amercan Rheumatsm Assocaton ndex [] (based on the sum of tender or swollen jonts n slghtly dfferent groups) and the Lansbury ndex [4] (based on graded nflammaton n jonts weghted for surface area). However, these are largely pan scores and do not correlate wth the acute phase response [5]. Measures of jont nflammaton whch are to be used as an ndcator of nflammatory actvty should correlate wth laboratory measures of nflammaton such as CRP and plasma vscosty (PV). Therefore a more fundamental approach to the development of an AI was taken by Thompson et al. [5] who used computer analyss to dentfy the combnaton of sgns, jonts and gradng of symptoms that was most effcent at summarzng overall nflammaton by correlaton wth CRP. Ths Thompson-Krwan AI (TKAI) records the presence or absence of soft-tssue swellng/effuson plus tenderness on frm pressure n selected jonts weghted for sze. Mason et al. have developed a self-report questonnare (RADAR) whch ncorporates a self-report AI but the resultant four-page questonnare was not valdated aganst laboratory measures of nflammatory actvty [6]. Stewart et al. [7] attempted to show that the TKAI s a relable measure of nflammatory actvty when completed by patents. Whlst self-reported Brtsh Socety for Rheumatology

2 548 BRITISH JOURNAL OF RHEUMATOLOGY VOL. 4 NO. 6 TKAI correlated well wth clncan TKAI, t dd not correlate wth CRP. However, the TKAI was desgned specfcally as a measure of health care professonals' ablty to assess jont nflammaton clncally and reles on ther sklls n elctng the presence of soft tssue swellng and the ablty to apply pressure over the jont margns. If they are to adequately assess ther own nflammatory actvty, patents may requre an AI wth a dfferent nternal structure, for example concentratng on dfferent symptoms or jonts or usng a dfferent method of gradng. In order to devse and valdate a relable self-report AI (SRAI) t s therefore necessary to approach t n the same manner as was used for developng the TKAI, rather than assume that any exstng ndex s the most approprate. The am of the study therefore was to develop an SRAI whch correlated wth the acute phase response. However, to do so requres the collecton of numerous data (grades of multple symptoms n multple jonts) and patents may fnd such a questonnare ncomprehensble or unacceptable. The frst steps were therefore to desgn an easly understood questonnare format and then to establsh whether or not patents can correctly dentfy ther jonts, a pre-requste before any SRAI can be tested and valdated. At the same tme smple vsual analogue scales (VAS) of pan and perceved 'dsease actvty' were assessed lest these alone mght suffce for patents to adequately self-report nflammatory actvty. PATIENTS AND METHODS Studes were ntally conducted n out-patents wth classcal RA [8] who were recruted whlst awatng ther out-patent consultaton, wth the fnal study beng conducted on n-patents admtted durng a flare of ther RA. Data collecton centred on self-reported graded symptoms (-) of pan, heat, stffness and swellng n 64 jonts. These jonts ncluded left and rght temporomandbular jonts, neck, shoulders, elbows, wrsts, metacarpal phalangeal jonts -5 (MCPs), proxmal nterphalangeal jonts -5 (PIPs), dstal nterphalangeal jonts -5 (DIPs), thumb nterphalangeal jont (IP), hps, knees, ankles, metatarsal phalangeal jonts -5 (MTPs), great toe nterphalangeal jont (IP) and combned proxmal and dstal nterphalangeal jonts -5 (toes) (IPs). Study was desgned to establsh a questonnare format for ths necessarly complex data set, whch patents could understand and complete wthout error. Twenty patents wth RA were asked to report the symptom of pan usng a questonnare lad out n three dfferent formats, whch were gven n random order. Format A comprsed a lst of jonts each accompaned by the numbers,, and to ndcate grade of pan. Format B was a lne drawn fgure wth blank crcles around the jonts, n whch the patent should wrte the number to ndcate the grade of symptom. Format C was an dentcal lst to format A but was accompaned by a drawng showng labelled jonts. On all formats lay terms were substtuted for medcal terms n the hands (knuckles for MCPs, mddle jonts for PIPs and end jonts for DIPs) and feet (base of toes for MTPs, toe jonts for IPs). After completon of all three formats each patent was asked whch of the three forms they preferred. Study was desgned to establsh whether or not patents could dentfy ther own jonts correctly usng ether format A or B (C havng beng dscarded on the results of the prevous study). Ten out-patents wth RA were gven format A (the lst) to complete and format B (the fgure). After they had completed the questonnare, usng the pan symptom only, ther dentfcaton of every jont (whether symptomatc or not) was checked by a clncal research assstant. Study was performed usng format A (the lst) to collect the data for developng and valdatng the SRAI. Format A was chosen on the bass of the results from studes and. Sxty-one out-patents wth RA were nvted to take part and 5 patents completed all the questonnares. These ncluded four grades for each of four symptoms for each of the 64 jonts lad out n format A (Fg. ) and cm VAS for pan and perceved dsease actvty. The queston on perceved dsease actvty read 'How actve has your arthrts been over the past 4 hours?' Patents were asked to complete all the questons n relaton to symptoms present over the last 4 h only. Inflammatory actvty was assessed by a clncal research assstant performng the TKAI and takng blood for CRP and PV estmaton (one patent dd not have PV measured). Data from the patents n study were analysed n a varety of ways, both n unvarate and multvarate analyses, n order to dentfy the combnaton of jonts and symptoms whch correlated most hghly wth measures of the acute phase response. Fnally, n study 4, n-patents admtted durng a flare of ther RA were recruted n a smlar manner and asked to complete the same data sets ( patents completed all data sets). RESULTS In study the lsts, wth or wthout accompanyng pctures (formats A and Q were preferred by 5% of patents whle 45% preferred the fgure (format B) and 5% had no preference. As patents were comfortable wth ether the lst or fgure t was decded to elmnate format C (combned lst/dagram) at ths pont as t added nothng extra. In study, 9% of the 8 jonts were correctly dentfed usng ether questonnare, ndcatng that ether format A or B would be acceptable. The fgure (format B) had the dsadvantage of requrng a separate dagram to be completed for each of the four symptoms (.e. four sheets of paper) and so t was decded to use the lst (format A) whch could convenently ft onto two sdes of paper, one for each of the left and rght sdes of the body (Fg. ). The 5 outpatents n study comprsed 7 females and males wth a mean age of 6 yr and dsease duraton of yr. They had moderate nflammatory

3 HEWLETT ET AL.: SELF-REPORT INFLAMMATORY ACTIVITY 549 actvty measured objectvely and reported subjectvely (Table I). The followng results apply to patents n study. In 58% of patents CRP levels were not quantfed more accurately than < mg/. Local laboratores are unable to quantfy CRP below mg/ even though such levels may ndcate consderable nflammatory actvty. Attenton was therefore focused on PV as beng the next most relable ndcator of actve nflammaton, where 64% of patents had levels >.7 mpas. Please ndcate whether the symptoms you have had n each jont over the LAST 4 HOURS s none (), mld (), moderate () or severe () YOUR RIGHT SIDE PAIN HEAT SWELLING STIFFNESS Jaw Neck Shoulder Elbow Wrst Hp Knee Ankle HAND: End jonts Lttle fnger Rng fnger Mddle fnger Index fnger HAND: Mddle jonts Lttle fnger Rng rnger Mddle fnger Index fnger Thumb HAND: Knuckles Lttle fnger Rng fnger Mddle fnger Index fnger Thumb FOOT: Toe jonts Lttle toe 4th toe Mddle toe nd toe Bg toe FOOT: Base of toes Lttle toe 4th toe Mddle toe nd toe Bg toe Fo. I. Frst page of the data collecton sheet.

4 55 BRITISH JOURNAL OF RHEUMATOLOGY VOL. 4 NO. 6 Patent Out-patents (n = 5) TABLE I demographc and dsease data In-patents (n = ) Mean Range S.D. Mean Range S.D. Age (yr) Dsease duraton (yr) Thompson-KJrwan AI CRP (mg/ml) PV (mpas) VAS dsease actvty VAS pan * (M9 < f.59f ^74 < T MWI NECX BJOULD ELBOWS WKBTf HOT KStXM ANCLES SXS HP» FlO.. Frequency of reported symptoms n dfferent jonts. MO* TOBS UTTl All patents reported some symptoms. Stffness was the most frequently reported symptom (47% of all possble occasons) followed by pan (4%) wth swellng and heat less often reported (4 and 6%). Symptoms were reported most frequently n the wrsts (pan 67%, stffness 66%, swellng 5%, heat 4%) and ankles (6, 55, 5 and %) whlst the least troublesome jonts were the jaws (pan %, stffness %, swellng %, heat 6%) and hps (4,, 8 and 6%) (Fg. ). By selectng only those jonts and symptoms ncluded n a TKAI t was possble to compare the clncal research assstant's evaluaton of the TKAI and the patents' reports of the same symptoms (pan plus swellng) n the same jonts (Fg. ). The patents' self-report TKAIs and research assstant's TKAIs correlated at.65 (P <.) and scores for ndvdual jonts or jont groups also showed sgnfcant correlatons (Table II). However patents' scores were often greater than the research assstant's evaluaton and the mean dfference between them was 45 (S.D. 4.6). Thus, assumng these dfferences to be normally dstrbuted, approxmately 5% of the patents' scores dffered from the research assstant's by at least 97 unts. Nether the patents' self-report TKAI nor the health care professonal's TKAI correlated wth PV (r =.4 and., respectvely). The relatonshp between each symptom and PV was ntally assessed usng unvarate correlaton coeffcents. The left and rght scores for each jont were added, producng a set of scores for each symptom n every jont. The DIPs were added and treated as a sngle unt, as were the PIPs, MCPs, MTPs and toes. Although PV was normally dstrbuted, the symptom scores had a hgh degree of postve skewness, thus Spearman's rank correlaton was used. The correlatons are shown n Table III. An ndvdual correlaton of the magntude of.8 or greater s

5 HEWLETT ET AL.: SELF-REPORT INFLAMMATORY ACTIVITY 55 a JOO 4 I, < * Ptent I ' T I- I : t - < _ m 5 patents Fo.. Thompson-KJrwan ndex. T ' > Nurse Correlatons between Elbows WrsU MCPs PIPs -5 IPs Knees Ankles MTPs -5 MTPs Overall TK ndex TABLE II professonal's and Krwan ndces *P <.5, *V<., /»<.. patents' ft* r -.68* r =.4* r =.56* r =.45* r =.7* ft* r -.66* r =.46* r-.54 r =.7** r =.65*** Thompson- TABLE III Rank correlatons between plasma vscosty and symptoms Jaws Neck Shoulders Elbows Wrsts MCPs PIPs Dffs IPs Hps Knees Ankles MTPs Toes Heat Pan Stffness Swellng sgnfcantly dfferent from zero at the 5% level but wth correcton for 54 correlaton coeffcents from 49 ndvduals only correlatons of a magntude of.485 or greater should be consdered sgnfcant. Only two correlatons were greater than.8 and none were greater than.458. Therefore there s no evdence to suggest that a patent assessment of jont symptoms could predct PV levels. However, n order to assess f a combnaton of jonts could predct PV, multple regresson was also used. Two methods were employed: stepwse regresson and best subsets. The former revealed lttle more than the smple correlatons descrbed above. The only combnatons found to be sgnfcantly related to PV were heat n the DIPs and MTPs, wth the MTPs beng negatvely related. The best subsets method was used to search through all models of a gven sze for each symptom and select the 'best' one, based on the R value. Mallow's C p was then used to select the most approprately szed model for each symptom. Each 'best' model ncluded a dfferent selecton of jonts. The R values for the 'best' models were 8.5% (heat), 5.5% (pan), 7.% (stffness) and.% (swellng). Agan some of the jont scores ncluded n these models were negatvely related to PV. In study 4 each of these four 'best' models was used to predct PV n a further group of n-patents admtted durng an exacerbaton of ther dsease, who had hgher levels of nflammatory actvty than the outpatent group (Table I). The actual and predcted PV values are shown n Table IV. No model was consdered to be adequate for PV predcton. There was no sgnfcant correlaton between PV and patent's VAS of pan or perceved dsease actvty for ether the out-patents n study (pan r =.6, perceved dsease actvty r =.) or the n-patents n study 4 experencng a flare (pan r =.47, perceved dsease actvty r =.9). DISCUSSION It mght have been expected that patents, partcularly those wth several years experence of fluctuatng jont nflammaton, would be able to accurately report

6 55 BRITISH JOURNAL OF RHEUMATOLOGY VOL. 4 NO. 6 TABLE IV PV predcted from four models of patent Al and actual PV (n PV predcted by model* Patent Pan Heat Stffness Correlaton! 95% CIJ lower 95% CI upper Pan model: jaws, wrsts, DIPs, knees (negatve), MTPs (negatve). Heat model: jaws, neck (negatve), shoulders, elbows, MCPs (negatve), DIPs. Stffness model: neck, wrsts (negatve), MCPs, hps (negatve), knees, toes (negatve). Swellng model: jaws (negatve), neck (negatve), shoulders, elbows, hps (negatve), MTPs (negatve). fpearson correlaton coeffcent for actual PV o model predctor. JCI = Confdence nterval. II) ; evdence of nflammatory actvty and thus our am was to develop an SRAI whch reflected such actvty by correlaton wth the acute phase response. It has not been possble to do so. Informaton on nflammatory actvty provded by the clncan's TKAI whch has been shown to correlate wth the acute phase response [5] cannot be replaced by relance on ether a complaton of patent's reports of symptoms, or a VAS for pan or perceved dsease actvty. It s possble that the number of patents wth relatvely lttle nflammatory actvty (as ndcated by CRP and PV levels) made ths an unsutable data set wth whch to attempt to construct a jont nflammaton measurement tool. However, any such tool must dentfy not only those patents wth nflammatory actvty, but also those wthout. In addton the only possble models constructed wth any lkelhood of success fared no better usng a set of n-patents wth consderable nflammatory actvty. Ths study used a very short tme-frame for reported symptoms (4 h) as opposed to Mason et al. [6] who used a 6-month tme-frame. It was antcpated that ths would gve greater correlaton wth current laboratory measures of nflammaton, enhanced by the fact that patents would not have to 'average out' ther symptoms over a long tme perod. However, nether ourselves nor Stewart et al. [7] (who also used ths short tme-frame) were able to produce an SRAI whch adequately reflected nflammatory actvty. Patents clearly experence multple symptoms (heat, pan, stffness and swellng) n multple jonts and are able to both dstngush and record the dfferent symptoms and ther severty n ndvdual jonts. Surprsngly, stffness rather than pan was the most frequently reported jont symptom, partcularly n the small jonts of the hands and feet. It s possble that stffness causes more dffculty than pan n performng fne movements and that ths awareness leads to greater reportng of stffness. However, health care professonals often ask about overall mornng stffness and rarely about stffness n ndvdual jonts, apparently a common problem for patents. The am of ths study was to develop an SRAI whch correlates wth the acute phase response but the desgn of the study also enabled us to compare the research assstant's TKAI wth a patent self-report TKAI. The moderate correlaton between these (r =.65) should not be over-nterpreted as the varatons between the researcher's and patents' scores vary wdely. The correlaton mrrors that found elsewhere (r =.5) [7] and s not unexpected as smlar features of arthrts are beng recorded, albet from dfferent perspectves. The TKAI was developed to reflect nflammatory actvty by correlaton wth CRP and although ths s not deal as.65, s the best out of all avalable AIs [5]. It does not appear to correlate well wth other nflammatory ndces as ndcated by the poor correlatons wth PV n ths study and ESR n Stewart et a/.'s study [7]. In common clncal practce the clncan stll requres the nformaton from the TKAI to be supported by laboratory measures of nflammaton for that patent. The patent self-report TKAI dd not correlate at all wth laboratory measures of nflammatory actvty ether n ths study (usng PV, r =.4) or Stewart's study (usng CRP, r =.5) [7] and thus clearly cannot be used as a surrogate for measurng the acute phase response. Thus two comprehensve studes have shown that whlst patents can complete a self-report TKAI n a way that moderately correlates wth a clncan's opnon, we cannot use ths tool to adequately report nflammatory actvty by correlaton wth the acute phase response (the am of ths study). In addton, the current study whch attempts to develop such an SRAI wthout any pror assumptons as to jonts, sgns,

7 HEWLETT ET AL:. SELF-REPORT INFLAMMATORY ACTIVITY 55 symptoms or gradngs (rather than utlzng the exstng Al such as the TKAI) could not develop an adequate self-report tool for nflammatory actvty. If clncan's are tempted to use an SRAI such as the TKAI they must be aware that ths wll not relably ndcate nflammatory actvty. The SRAI however, should not be dsmssed altogether. Patents are clearly able to dfferentate and report varous jont sgns and symptoms at dfferent levels. Further work needs to be carred out to explore the sgnfcance of these reports and whether they are senstve to treatment changes, or fluctuatons n psychologcal status or pan, n whch case they may well be a valuable contrbuton to our assessment of the patent. The nature of the nformaton provded by an SRAI needs to be more precsely establshed before t can be used as an assessment tool n ts own rght. It should not be used merely because t moderately correlates wth the TKAI whch was desgned as a measure of nflammatory actvty, when t has been shown that the SRAI does not, n tself, correlate wth the acute phase response. ACKNOWLEDGEMENT The authors wsh to acknowledge the support of the Arthrts and Rheumatsm Councl n fundng ths research project (grant KOO8). REFERENCES. Pncus T, Callahan LF. Quanttatve measures to assess, montor and predct morbdty and mortalty n rheumatod arthrts. In: Scott DL, ed. Clncal rheumatology. The course and outcome of rheumatod arthrts. London: Ballre Tndall, 99:Chapter 8.. Rtche DM, Boyle JA, Mclnnes JM et al. Clncal studes wth an artcular ndex for the assessment of jont tenderness n patents wth rheumatod arthrts. Q J Med 968:7: Co-operatng Clncal Commttee of the Amercan Rheumatsm Assocaton: A seven day varablty study of 499 patents wth perpheral rheumatod arthrts. Arthrts Rheum 965* Lansbury J, Haut DD. Quanttaton of the manfestatons of rheumatod arthrts. Four areas of jont surfaces as an ndex to total jont nflammaton and deformty. Am J Med Sc 956^: Thompson PW, Slman AJ, Krwan JR, Currey HLF. Artcular ndces of jont nflammaton n rheumatod arthrts. Arthrts Rheum 987;O: Mason JH, Anderson JJ, Meenan RF, Haralson KM, Lews-Stevens D, Kane JL. The rapd assessment of dsease actvty n rheumatology (RADAR) questonnare. Arthrts Rheum 99;5: Stewart MW, Palmer DG, Knght RG. A self-report artcular ndex measure of arthrts actvty: nvestgatons of relablty, valdty and senstvty. J Rheumatol 99;7:U Arnett FC, Edworthy SM, Bloch DA et al. The Amercan Rheumatsm Assocaton 987 revsed crtera for the classfcaton of rheumatod arthrts. Arthrts Rheum 988::5-.