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I I I I I I I I I I I I I AdJu'1n r Nrh- wrt, Vol. 13(11. pp 87-90. 19tS8 03o6-4so3r88 s3.oo • .00 Printed ;n the USA. AII n8hts reser.eJ. Copynght e 1988 Nrtamon Journals Ltd BRIEF REPORT FAILURE TO SUPPORT THE VALIDITY OF THE FAGERSTROM TOLERANCE QUESTIONNAIRE AS A MEASURE OF PHYSIOLOGICAL TOLERANCE TO NICOTINE THOMAS W. LOMBARDO University of Mlsussippi JOHN R. HUGHES University of vermont JEFFREY D. FROSS University of Mississippi Absars,cs - We tested the validity of the FasentrGm Tolerance QuestionnLire as a measure of physiolopcaJ tolerance to nicotine. Both clinical and laboratory studies found neither the total questtonnarrc score nor the individuaJ qusstionnaire items were related to physiolopcal tulennce as measured by hean nte, skin conducunce, b4ood volume putsa, and skin tem• peraturc responses to smoktnt; a clSareite. We hypotheuu the questionnairr meawres behavioral dependence or perceived dependence rather than physical dependence, Fagerstrom (1978) developed a Tolerance Questionnaire to measure dependence on nicotine amon; smokers. The validity of this questionnaire has been tested in several ways. Some studies have found smokers defined as dependent by the questionnaire exhibit more withdrawal symptoms, more compensation when switched to low nicotine cigarettes, less success in smoking abstinence, and increased likelihood to rcspond ;o nicotine gum treatment. Other studies have failed to replicate these results. (See Hughes (19851 for a review.) Only one study has evaluated the validity of the Fagerstrom questionnaire as a measure of physiological tolerance ; Fagerstrom, 1978). This study found a significant correlation (r - -.69) between the total tolerance questionnaire score and peak heart rate boost after smoking one cigarette ad lib. We now report two :tudies from independent laboratories that failed to replicate this finding. STUDY I I I I I I Method Subjects. Subjects were 99 smokers who were about to participate in a smoking treatment study (Hughes et al„ 1984). Subjects fulfilled DSM•111 criteria for tobacco dependence and a hirtory of tobacco withdrawal ;Table 1). Supported by a grant•in•aid from Energetics Science, Elmsford, NY. hy agnnt from Merrell•Dow Pharmaceuticals, grants (DA•0372tt and DA•01P44). a Research Scientist Development Award (DA• 00109) from the National Institute on Drug Abuse, and funds fkom the State of Minnesota for psychiatric research, and by a University of Mississippi Faculty Research Gnnt. Requests for repnnts shoulJ be sent to Thomas W. Lombardo, Department of Psycholotsy. University of Misstssippi, University. MS 38677. 87 I

I I I I I I I I I I I I I I I 88 T.w. LOMBARDO. J.R. HUGHES. and J.D, FROSS Table 1. Sample chancteristics Study I Study 2 t1.S. Averat;e' Fagerstrom (197{) N 99 30 Na 19 Age . 37 :1 Na 36 ''i Males 55 50 55 26 Cigarettes/day 30 li 24 19 Nicotineicigantte (mt;) 0.8 0.7 1.1 n/a Yean of smoking IS 3 21 11 •U.S. Average frore U.S tkpannwnt o( Heatth and Human Servuef c 1" c). Na - Nut Available. Procedures. Subjects completed the Fagerstrtlm questionnaire and a questionnaire about their smoking that day. A blood sample was drawn for plasma nicotine, and subjects' radial pulse was measured for 30 s. Subjects then smoked their usuat cigarette in their usual manner. Two minutes later, a second blooJ sarnple and pulse were obtained. Plasma nicotine was measured by radioiminunoassay by the Ameri- can Health Foundation (Valhalla, NY). Three dependent measures were analyzed. Nicotine boost and heart rate boost were obtained by calculating the increase in each of these measures from smoking. A physiological tolerance score was calculated as heart rate boost divided by nicotine boost and corrected for body weight. The total score on the Fagerstr8m question• naire and the individunl questionnaire items were correlated with each of these thre: dependent measures. Time since the last cigarette and number of cigarettes smoked on the day of the test were partialled out beforehand. Results The total Fagerstrt5m score was not correlated with the physiological tolerance score (r =.04). The total score was modestly correlated with nicotine boost (r - .28. p < .01) but not with heart rate boost (r - .13). Anal-,,ses of covariance on the eight individual questionnaire items showed only one item significantly predicted the phys• iological tolerrnce score, that is, the item "Smoke When Itl". F( l, 88) - 6.4, p< 01,11 (Table 2). STUDY 2 Study I was a clinical test of the validity of the Fagerstrlfm questionnaire. Al- though the subjects were comparable to the national average (see Table 1), the study lacked experimental control over two important variables: deMe of smoking depri- vation and nicotitac dose. In addition, Study I used only one physiological measure of tolerance. Study 2 was designed as a more rigorous labotatory test of the validity of the Fagerstrdtn questionr.aire that would correct these methodological limitations. Method Subjects. Subjects were 30 college undergraduates. To increase the range of tolerattce, the only inclusion criterion was that subjects must have smoked for at ;east one year, and the only exclusion criterion was that subjectY had to be taking no medication (Table 1). Procedur..s. Subjects were i.~tstructed to abstain from smoking overnight and to report to the labot2tory in the morning. To verify abstinence, alveolar carban

I I I I I I I I I I I I I I I I I v.hdlty of the Tolerance Questionnaire 89 Table :. Correlations between total Faserstrom questionnaire and ph) swlneIcal measures of tolerance STUDY I STUDY 2' Measurc r Meuure r HR t+Wa .13 Heart rate (peak) .OE Nlcotine txK+,t .:E•• Mean rate (mean) .32' Tolerance .core .01 Skin temperature .20 Blood volume pulse .3R• Skin eonductrnce .19 'SiIndicani v.lues ue opposite to tAe eapected direction. •,, . .0!. •-r < 01L monoxide was measured (Hughes. Frederiksen, & Frazier, 1978). Subjects com- pleted the Fagerstrom questionnaire and then had leads attached for elec- trophysiological recording. After a 10 minute adaptation period, five minutes of baseline were obtained. Subjects then smoked one cig>tirette. Post-smoking meas- urements were obtained for five minutes after smoking. To ensure that all subjects received the same dose of nicotine, they were adminis- tered teri 35 ml puffs from an 0.8 mg nicotine yield cigarette at the rate of one puff/minute. The dosing apparatus consisted of a syringe. T-valve, and polyvinyl tubing. Subjects inhaled each r•tf deeply and held the puff for three to four seconds to maximize nicotine absorpLion. Four physiological responses were recorded: heart rate (HR), skin conductance level (SCL). skin temperature (ST). and blood volume pulse (BVP). HR and ST were recorded every 30 s with a digital photoplethysmograph and with an Autogen feed- back thermometer and thermistor. SCL and BVP were recorded with a Grass model 7D polygraph. For HR. physiological tolerance was computed in two ways: as the difference between the mean HR during baseline and the mean during the five minute post- smoking period ("mean HR") and as the difference between baseline and the peak HR dcring the post-smoking period ("peak HR"). For ST. SCL, and BVP only mean scores were used. ST was determined in the same way as "mean HR." BVP wks computed as the percentage decrease from baseline to post-smoking levels. For SCL. tolerance was computed as the log of the difference between conductattce values during baseline and post-smoking periods. Results Subjects in Study 2 were less behaviorally dependent than those in Study I and than the national average (Table 1). Self-report and alveolar carbon monoxide analyses indicated all subjects were abstinent as requested. The total Fagerstrom score was not correlated with peak HR. ST, or SCL. The mean HR and the BVP correlations were significant but opposite to the expected direction. None of 30 item analysis ANOVAs were signtficant. Table 2 summarizes these results. Discussion Both the clinical study and thc laboratory study failed to support the validity of the Fagerstrom questionnaire as a measure of physiological tolerance to nicotine. I

I I I I I I I I I I I I I I I I I . 90 T w. LOMBARDO. 1.R. HUGHES. and 1.D. FROSS Ne;ther the total Fagerstrorrt score nor individual items were consistently related to the physiological measures of tolerance. The Fagerstrbm questionnaire was intended to be a measure of "dependence" among smokers. The present studies indicate that the scale does not predict tolerance, and a previou; study (Hughes & Hatsukartti, 1986) indicates the scale does not predict tobacco withdrawal. Thus. the questionnaire does not appear to measure ph.Ysical dependence. One possible explanation for these negative results is that the qucstionnaire items were selected by ciinical intuition rather than etnpirical criteria. Although the items are face valid, some may be invalid. For example, the "Do You Inhale?" item may be invalid, as self-reported "noninhalers" appear to inhale nearly as much as "deep inhalers" (Wald. Idle, & Bailey, 1978). Similarly, the "High- Medium-Low Cigarette Nicotine Yield" item may be invalid, as nicotine yield is only weakly related to nicotine intake measured biochemically (Benowitz et al., 1983). Findings that the Fagerstrom questionnaire predicts the inability to stop smoking and the self-administration of nicotine (Hughes, 1985) indicate the scale may meas- ure behavioral dependence (i.e.• persistence of smoking) rather than physical de- pendence. Another possibility is that the FagerstrtSm questionnaire measures neither physical nor behavioral dependence, but measures perceived dependence. Study 2 subjects' responses to the question "How difficult would it be for you to go three days without taking one puff from a cigarette?" were correlated with the Fagerstram questionnaire (r -.67, p < .001) supporting this hypothesia. Additional support comes from evidence that knowledge that one is receiving nicotine is necessary for the therapeutic benefits of nicotine gum (Hughes. Pickens, Sprin„• & Keenan, 1985), and, more importantly, that the questionnaire identifies those subjects for whom nicotine gum is effective only when they believe they are receiving nicotine (Fagerstr8m & atorm, 1981). Thus, the Fager.:r8m questionnrare may predict behav- ioral dependence simply because it identifies smokers who strongly believe that nicotine is an essential part of their smoking habit. REFERENCES Renowitz. N.L.. Hall. S.M.. Hernins. R.L. Jaeob, P.• Jones. R.T., 3 Osman. A. 119l3). Smokers of )ow•yield ciµrettes do not consume less nicotine. New England Joarnal u/.Nrdicinr. 30l. 139-142. Fagentrom. K.O. (1978). Measurint de{ree of physical dependence to tobaeco smoking with reference to individualization of treument. Addictive Brhavio.s. 3, W-241. FagentrOm, K.O.. & Storm. H. 0911). The etTects of ditTerent insttuctions on swking cessation for individuals with difreront degrees of dependence. Bthavioural Pryrhotherapy. !, 310-315. Hughes. J.R. (19EJ). Identiftcation of the dependent stnoker. Validtty and eUnical utility. Bshevio.a! Medicine Absrrocrs. S. 202-204. Hughes. J.R.. Fredenksen. L.W.. A Ftszkr. M.A. (197a). A carbon monoxide uulyzer for measurement of smoking behavior. Behavior Thrropy f. 293-2%. Hughes, J.R.. t Hatsukami• 0. (1966). Signs and symptoms of tobacco withdrawal. Archives n/Ger+eral Pf ych(atry. 43. 289-294. Hughes. J.R.. Hatsukami. D.K.. Pickens, R.W.. Krahn. D., Ma)in• S., k Luknic. A. (f964). Effect of nicottne on the toba.co withdrawal syndrome. Ps,vchnpha.macolory, a3, t;2-tt7. Hughes. J.R.. Pickens. R.W.. Spnns. W.. & Keenan. R.M. (19d3). Instructions control whether nicotine will serve as a reinforcer. Jnurnal of Ph.mnucofogy B Fspt•rirnrnra( Therap.wics. 235. t06-t l2. U.S. Department of Health and Human Serv,ces. (19i)1. The health conuqr«ncrs nj smo4ing. The chanl,•ina ciparettr A report a/th. Surrrnn General. U.S. DHHS Publication No. (PHS)8I•X'136. Wald. N.. Idle. M.. & Bailey. A. (1978). Carboxyharmoglobin levels and inhaling habits in cigarette smokers. Thorax. 33. 201-206.