Health-Related Quality of Life in Asymptomatic Patients with HIV

Health-Related Quality of Life inAsymptomatic Patients with HIVEvaluation of the SF-36 Health Survey in Italian Patients

Fabio Arpinelli,1 Giovanni Visonà,1 Raffaele Bruno,2 Gianfranco De Carli1 and Giovanni Apolone3

1 Medical Department, Glaxo Wellcome S.p.A., Verona, Italy2 Clinic of Infectious and Tropical Diseases, University of Pavia, Istituti Ricovero e Cura a Carattere

Scientifico (IRCCS), S. Matteo, Pavia, Italy3 Istituto Ricerche Farmacologiche Mario Negri, Milan, Italy

Abstract Objective: To investigate the psychometric performance and clinical validity ofthe 36-Item Short Form (SF-36) health survey when completed by asymptomaticHIV-positive Italian patients and to compare their health profile with a repre-sentative sample of 2031 Italian citizens (the Italian norm).Patients and Methods: This was an observational, multicentre, cross-sectionalsurvey. Microbiologists throughout Italy recruited asymptomatic HIV-positiveindividuals who were aged at least 18 years and aware of their infection. Inves-tigators collected demographic, social, clinical and treatment data. Patients, clas-sified into 2 clinical categories (A1 and A2) according to explicit pre-definedcriteria, completed the SF-36 health survey in the context of a medical visit.Results: Between April and July 1996, 46 microbiologists recruited 214 patients(201 evaluable). No inconsistent responses were observed in 96% of the sample.The usually recommended psychometric standardswere satisfied, and the internalconsistency reliability indices were always greater than 0.70. Weak to moderateassociations were found between SF-36 health survey scores and physicians’estimates of patients’ physical performance, while no significant associationswere found with CD4+ counts.On average, HIV-positive patients reported lower scores than the Italian norm,and patients in category A2 showed lower scores than patients in A1. Thesedifferences were more relevant in scales describing role limitations, generalhealth perception, and psychological well-being.Conclusion: Our study showed that the SF-36 health survey maintained its psy-chometric properties in a sample of Italian asymptomatic HIV-positive patientsand produced data that showed its validity and robustness in such a setting.

ORIGINAL RESEARCH ARTICLE Pharmacoeconomics 2000 Jul; 18 (1): 63-721170-7690/00/0007-0063/$20.00/0

© Adis International Limited. All rights reserved.

The natural history of HIV infection is charac-terised by an asymptomatic period lasting severalyears. During this period several factors are poten-tially able to negatively affect a patient’s subjective

functioning and well-being, such as social stigma,fear of infecting relatives, and concern about theoccurrence of clinical events that are consideredcapable of changing prognosis and quality of life.

Although the debate is still ongoing regardingthe actual value of markers in clinical decision-making, the CD4+ lymphocyte count is often usedto monitor the disease evolution and thus is consid-ered, at least by patients, an indicator of their pres-ent and future health status.Despite these considerations, there are few data

about how and in what manner patients’ subjectivehealth status is affected by factors related to HIVseropositivity in the early stage of infection. In thelast few years, quality of life and health-related qual-ity of life (HR-QOL) principles have become fa-miliar terms with physicians who are interested inhumanistic outcomes of the care offered.[1-9] Amongthe generic instruments available, the 36-ItemShortForm (SF-36) health survey is one of themost widelyused because of its characteristics of comprehen-siveness, brevity and high standard of reliability andvalidity.[10-13] A few disease-oriented questionnaires,focused either on AIDS or HIV-positive status, arealso available. Among the several recommendationssummarised in the final report of a state-of-the-artmeeting held in Paris in 1996[14] was a comprehen-sive approach to the assessment of treatment out-comes in early HIV, using both psychometric- andutility-based approaches, and either HIV-targetedor generic descriptive instruments (for example, theSF-36 health survey).According to these recommendations, the SF-36

health survey questionnaire was cross-sectionallyadministered to a well characterised sample of indi-viduals. This article presents analyses carried out to:• evaluate the acceptability and psychometric per-formance of the Italian version of the question-naire when administered in such a setting

• investigate the relationships between SF-36 healthsurvey scores and a selected list of clinical vari-ables, with special attention to the CD4+ countand the physicians’ evaluation of patients’ per-formance

• compare the SF-36 health survey health profilesof the present sample with those obtained froma representative sample of Italian citizens (theItalian norm).

According to the published data on the SF-36health survey performance in other medical condi-tions and the findings from clinical research on HIV-positive patients, we expected that the questionnairewould satisfy the recommended standards in termsof acceptability and psychometric performance, thatHIV-positive patients would report lower scores thanthe normative sample, and that health profiles wouldbe worse in patients classified as being in a moresevere stage of disease.

Methods

Study Design

Participants were identified and recruited in thecontext of an observational, multicentre, cross-sec-tional survey carried out in Italy during 1996, inoutpatient hospital facilities that agreed to partici-pate on a voluntary basis. Each investigator wasasked to recruit the first 5 eligible patients whocame to the centre for any medical reason.

Sample Size

The sample size was estimated to detect a 10-point group difference in SF-36 health survey scalescores, comparing HIV-positive patients with theItalian norm, assuming a non-directional hypothe-sis (2-tailed test) with a false-positive rejection rateof 5% and a statistical power of 80%. In other words,according to the statistical assumptions and the avail-able normative data,[13,15-17] 200 patients were es-timated to be sufficient to detect a real differencein either direction for all scales in the case of a 10-point difference, and for most scales in the case ofa 5-point difference.

Patients

Eligible participants wereHIV-positive, asympto-matic patients (clinical categories A1 and A2 accord-ing to the1993RevisedClassification System forHIVInfection and Expanded Surveillance Case Defini-tion for AIDS among Adolescents and Adults),[18]who were at least 18 years of age, aware of theirinfection, not current substance abusers, and freefrom any other co-existing acute disease.

64 Arpinelli et al.

© Adis International Limited. All rights reserved. Pharmacoeconomics 2000 Jul; 18 (1)

On the basis of the above mentioned classifica-tion system, the clinical category A consisted of 1or more of the following conditions: asymptomaticHIV infection, persistent generalised lymphadeno-pathy, acute (primary) HIV infection with accom-panying illness or history of acute HIV infection.According to the T lymphocyte counts, HIV patientswere then divided into categories according to theCD4+ counts as follows: (i) >500 cells/μl; (ii) 200to 499 cells/μl; and (iii) <200 cells/μl.Patients eligible for the present survey needed

to be asymptomatic with a CD4+ cell count ≥200cells/μl (A1-2). All patients were asked for andgave informed consent.

Data Collection

The SF-36 health survey questionnaire was ad-ministered and completed by patients at the timeof the visit. They also provided demographic andsocial data (gender, age, marital status, workingstatus). Investigators reported information on thedisease, treatments and patient performance (i.e.the Karnofsky Performance Status score[19]) usingstandardised forms.

The HR-QOL Instrument

The SF-36 health survey questionnaire, whichis one of the most widely used HR-QOL instru-ments,[10-13] is a generic questionnaire that meas-ures 2 major health concepts (physical and mentalhealth) with 36 items and 8 multi-item scales: Phys-ical Functioning (PF), Role Functioning Physical(RP), Bodily Pain (BP), General Health (GH), Vital-ity (VT), Social Functioning (SF), Role Function-ing Emotional (RE) and Mental Health (MH). Anadditional 1-item measure of self-evaluated changein health status is also available (table I). Scores areassembled using the Likert method for summatedratings[20] and then the raw scores are linearly trans-formed to 0 to 100 scales, with 0 and 100 assigned tothe lowest and highest possible value, respectively.Higher transformed scores indicate better health.Two component summary scores, one concerningthe physical dimension and the other concerning themental, were also calculated as a result of aweightedcombination of the original scales.[21] The SF-36health survey has been available in Italian since1990 and the launch of the International Quality-Of-Life Project has made possible the use of datafrom several comparable applications throughoutthe world.[22-24] A standardised Italian version is

Table I. Information obtained using the 36-Item Short Form (SF-36) health survey status scales[13,17]

Scales No. ofitems

No. oflevels

Summary of contents

Physical functioning 10 21 Extent to which health limits physical activities such as self-care, walking, climbingstairs, bending, lifting, and moderate and vigorous exercises

Role functioning physical 4 5 Extent to which physical health interferes with work or other daily activities, includingaccomplishing less than wanted, limitations in activities, or difficulty in performingactivities

Bodily pain 2 11 Intensity of pain and effect of pain on normal work, both inside and outside the homeGeneral health 5 21 Personal evaluation of health, including current health, health outlook, and

resistance to illnessVitality 4 21 Feeling energetic and full of pep versus feeling tired and worn outSocial functioning 2 9 Extent to which physical health or emotional problems interfere with normal social

activitiesRole functioning emotional 3 4 Extent to which emotional problems interfere with work or other daily activities,

including decreased time spent on activities, accomplishing less, and not working ascarefully as usual

Mental health 5 26 General mental health, including depression, anxiety, behavioural-emotional control,general positive affect

Health transition 1 5 Evaluation of current health compared with one year ago

Evaluation of SF-36 in Early HIV Patients 65


now available after an exhaustive test in more than10 000 individuals, including a representative sam-ple of 2031 Italian citizens.[16,17,22-24]

Statistical Analysis

Patient acceptability has been assessed using theproportion of missing data at item and scale level.In addition, the Response Consistency Index (RCI)showing the percentage of logical inconsistencieswas then computed. The RCI analyses individual

responses using internal checks based on the answerof 15 pairs of pre-identified items.[13,17] Groupingand scaling assumptions were assessed using stand-ard psychometric analyses described in the paperspresenting the original questionnaire.[11-13] Briefly,as the questionnaire is based on a multidimensionalconceptualisation of health, the multitrait analysis ap-proach[25] was adopted to test whether the con-ceptualisation in domains fits the data, and whetherthe characteristics of the scales replicate the eval-

Table II. Sample characteristics and comparisons with those of the Italian normative sample

Category A1 (n = 81) Category A2 (n = 120) Italian norm (n = 2031)Gender Male 61.7% 71.2% 49.2%

Female 38.3% 28.8% 50.8%NR (no.) 2

Age (years) 18-34 61.3% 61.9% 27.6%35-44 25.0% 29.7% 18.4%45-54 10.0% 5.1% 17.3%≥ 55 3.7% 3.4% 36.7%NR (no.) 1 2Mean (SD) 34 (8) 35 (8) 47 (17)Range 23-61 21-68 18-96Median 32 33 47Q1-Q3 29-37 30-38 33-60

Marital status Single 54.7% 59.5% 22.5%Married 26.7% 23.3% 67.6%Widowed 10.7% 9.5% 8.0%Divorced 8.0% 7.8% 2.05NR (no.) 6 4

Last CD4+ count (cells/μl) Mean (SD) 687 (186) 346 (86) NRRange 503-1330 206-496 NRMedian 640 350 NRQ1-Q3 553-753 275-418 NR

Karnofsky index Mean (SD) 99 (3) 97 (6) NRRange 90-100 70-100 NRMedian 100 100 NRQ1-Q3 100-100 100-100 NR

Any treatment? No 70.4% 35.0% NRYes 29.6% 65.0% NR

Number of drugs 0 70.4% 35.0% NR1 16.0% 21.7% NR≥ 2 13.6% 43.3% NR

Modality of infection Sexual 55.7% 51.7% NRDrug injection 36.7% 42.4% NRBlood transfusion 1.3% 0% NRUnknown 6.3% 5.9% NRNR (no.) 2 2 NR

NR = not recorded; Q1-Q3 = lower-upper quartiles; SD = standard deviation.

66 Arpinelli et al.


uation performed for the original questionnaire:convergence, divergence and internal consistencyreliability (Cronbach’s alpha)[26,27] were evaluated.The Karnofsky Performance Status score and

last CD4+ count were correlated to the score in eachdimension using Spearman correlation coefficients.The A1 and A2 groups’mean scores were comparedusing the 2-sided Student’s t-test. Differences weretransformed into standard deviation (SD) units di-viding the mean change in each score by the corre-sponding SD of the whole sample.[15,28] The HR-QOL groups’mean scores of the whole sample andof the 2 clinical A1-2 categories were also comparedwith the normative sample using analysis of covar-iance allowing for effects due to gender and age.The Scheffè multiple comparison procedure wasused to compare groups.[29]Given the large number of statistical tests car-

ried out, reported p-values should be interpretedcautiously as indicative of a trend. Data analysisand statistics were performed with the SAS® (Re-lease 6.12) package.

Results

Between April and July 1996, 46 investigatorstook part in the survey. Of the 214 patients recruited,201 (94%) were considered valid, while 13 wereexcluded from the analysis because of missing datain clinical variables, such as disease status, medicaltreatments, etc.Thecharacteristicsof thevalidpatients,together with a comparison with the normative sam-ple of the Italian general population, are reportedin table II. The 2 patient groups consisted of 81(A1) and 120 (A2) individuals, respectively, withsimilar demographic features. The Karnofsky in-dex (KI) was 100 for more than 75% of patientsand the percentage of patients receiving any treat-ment increasedwith increasing disease severity, from29.6 (group A1) to 65% (group A2).

Acceptability and Descriptive Statistics

The percentage of patients who completed ev-ery item in each of 8 scales ranged from 94 to 98%,with the percentage of computable scales rangingfrom 96 to 100%. The RCI estimates confirmed

the good acceptability of the questionnaire: the fre-quency distribution for the inconsistency matchedthe findings from the Italian and US normative sam-ples well.[13,16]As expected, given the characteristics of the

questionnaire, the ceiling effect (namely, the per-centage of participants receiving the maximum pos-sible score) was present in negative and monopolarscales measuring limitations, such as PF, RP, BP,SF and RE. For these scales, the highest possiblescore was achieved when no limitations or disabil-ities were observed. In the other 3 bipolar scales(GH, VT and MH), measuring a wider range ofeither positive or negative health states, the phe-nomenon was less evident (tables III and IV).

Psychometric Performance

Table V summarises the psychometric charac-teristics of the questionnaire. Data confirmed thatthe multidimensional conceptualisations in domainsand scales fit the present data: all scales satisfiedthe usual psychometric standards. In all cases, thewithin-scale correlation coefficients were quite ho-mogeneous, with within-scale coefficients alwayshigher than 0.40 (convergent validity), and higheritem scale correlationswere foundwithin scale ratherthan between scales (discriminant validity) in mostof the cases. The internal consistency reliabilityindices (Cronbach’s alpha) were always greater than0.70, the standard recommended for group com-parison, with most scales approaching 0.80.

Table III. The 36-Item Short Form (SF-36) health survey accept-ability and data quality: frequency of the response consistencyindex distribution and comparison with Italian and US normativesamples

No. ofinconsistentresponses

Italian generalpopulation(n = 2031) [%]

US generalpopulation(n = 2474) [%]

PresentHIV-positivepopulation sample(n = 201) [%]

0 92.6 90.3 96.01 4.0 6.1 3.02 or more 3.4 3.6 1.0



Clinical Validity

Table VI shows the associations between SF-36health survey scores, theKI scores and CD4+ counts.In the case of the association betweenHR-QOLandKI scores, correlations wereweak tomoderate (range0.16 to 0.32, median 0.21) and (as expected giventhe nature of theKI scores inmeasuring physicians’perceptions of patients’ performance in terms ofphysical and functional status) it was correlatedmorewith scores pertaining to the physical health do-main [PF, RP, BP, GH and physical component sum-mary (PCS) scales] than with those of the mentaldomain [VT, SF, RE, MH and mental componentsummary (MCS)].With regard to the strength, direction and statis-

tical significance of the correlationwith CD4+ count,although the same phenomenon was observed (i.e.higher correlations in the case of physical scales),the associations were weaker (range –0.001 to0.23, median 0.08), reaching relevance and statis-tical significance only in the case of BP, GH andPCS. In order to better describe the clinical rele-vance of the correlation between CD4+ count andSF-36 health survey scores, we carried out an anal-ysis of variance, which compared groups of pa-tients classified into 2 categories, A1 and A2. Asshown in table VII, in terms of mean group differ-ences or SD units, BP, GH and RPscales were moreimpacted, together with the PCS.

Normative Comparison

Table VIII shows the comparison between thehealth profiles of the normative sample and the pres-

ent sample split into 2 categories. In general, HIV-positive patients reported lower scores in both healthconcepts. Patients in category A2 had lower scoresthan patients in A1 in all but one scale (SF), withsomewhat larger differences in scales describinglimitations due to physical problems (RP), generalhealth perception (GH), and and bodily pain (BP).In addition, patients in category A2 had lower scoresthan the Italian norm in all but one scale (BP), withstatistically significant differences (p < 0.01) in thecase of RP, GH and MH scales.

Discussion

The use of HR-QOL measures has become anessential component of the evaluation of healthcareinterventions in several diseases. Although the de-bate is still ongoing,[4,5,9] the amount of availabledata has increased to such an extent that many au-thors have expressed concern that instruments andmethods are being inappropriately used.[30,31] In thecase of HIV treatment strategies, the debate on thevalue of HR-QOLmeasures led to the organisation ofan international state-of-the art meeting in Paris in1996.[14] According to the recommendations sum-marised in the final report,[14] we administered theSF-36 health survey to a well characterised sampleof Italian patients with early stage HIV disease toinvestigate the psychometric performance and clini-cal validity of the SF-36 health survey, and to betterunderstand the impact of the disease and of disease-related factors on the patients’ subjective health sta-tus. The availability of scores from a representativesample of the Italian general population has also

Table IV. Descriptive statistics and features of score distribution

Sample (n = 201) PF RP BP GH VT SF RE MH PCS MCSMean 92.0 82.5 86.8 55.5 65.2 77.3 74.4 65.4 52.8 45.3Standard deviation 14.8 31.0 21.2 22.7 19.1 23.2 36.8 19.0 6.8 11.0Range 0-100 0-100 10-100 0-100 5-100 0-100 0-100 8-100 30-68 13-70Median 100 100 100 57 65 88 100 68 54 4825th-75th percentiles 90-100 75-100 74-100 40-72 55-80 63-100 33-100 52-80 50-57 37-55% Ceiling 54.1 68.8 64.7 0.5 3.1 34.8 61.6 2.1 0 0% Floor 0.5 7.5 0 0.5 0 0.5 13.1 0 0 0BP = bodily pain; GH = general health; MCS = mental component summary; MH = mental health; PCS = physical component summary;PF = physical functioning; RE = role functioning emotional; RP = role functioning physical; SF = social functioning; VT = vitality.

68 Arpinelli et al.


made it possible to evaluate the impact of such fac-tors in terms of health profiles.The present data showed that the questionnaire

performance was good in terms of patients’accept-ability and psychometric performance: data actu-ally replicated the findings reported for the SF-36health survey when applied to Italian or interna-tional samples.[11,12,16,17,22,23] The tendency we ob-served for patients to cluster at the high end of themeasurement in monopolar limitation scales, al-though expected for the characteristics of the sam-ple under evaluation (relatively healthy individuals)and the questionnaire adopted (a generic survey),

suggested a potential limitation to discriminate be-tween subgroups or to detect change over time, atleast in these scales.In this sample, SF-36 health survey scores were

more associated with the KI (range of correlations:0.17 to 0.32,median 0.21) thanwith theCD4+counts(range –0.001 to 0.23, median 0.08). After adjust-ing for imbalance due to age, gender and presenceof treatments (yes/no), the group of patients withlower CD4+ counts reported significantly lowerscores, mainly pertaining to the physical domain.When compared with Italian citizens, both CD4+groups reported lower scores in both health con-

Table VI. Correlations between 36-Item Short Form (SF-36) health survey scales, Karnofsky index and CD4+ count

Scales Karnofsky index Last CD4+ countra p-value ra p-value

Physical functioning 0.297 <0.001 0.076 0.315Role functioning physical 0.323 <0.001 0.099 0.187Bodily pain 0.174 0.015 0.238 0.001General health 0.289 <0.001 0.194 0.010Vitality 0.233 0.001 0.122 0.111Social functioning 0.191 0.007 –0.001 0.989Role functioning emotional 0.170 0.018 0.013 0.861Mental health 0.166 0.028 0.062 0.420Physical component summary 0.296 <0.001 0.246 0.002Mental component summary 0.143 0.055 0.041 0.604a Indicates Spearman correlation coefficient.

Table V. Summary of psychometric results

Scales No. ofitems

Range of item correlations Item scaling tests Scaleinternal consistencya discriminant validityb success ratec success rated alphae

Physical functioning 10 0.45-0.74 0.06-0.52 100% 97% 0.88Role functioning physical 4 0.64-0.68 0.30-0.67 100% 100% 0.83Bodily pain 2 0.84 0.36-0.64 100% 100% 0.91General health 5 0.42-0.65 0.11-0.56 100% 100% 0.78Vitality 4 0.50-0.71 0.10-0.67 100% 93% 0.78Social functioning 2 0.68 0.15-0.63 100% 100% 0.81Role functioning emotional 3 0.60-0.68 0.34-0.69 100% 95% 0.79Mental health 5 0.43-0.67 0.13-0.65 100% 94% 0.81a Correlations (minimum-maximum) between items and hypothesised scale corrected for overlap.b Correlations (minimum-maximum) between items and other scales.c Item convergent validity scaling success = number of item scale correlations greater than 0.4/total number of correlations (corrected for

overlap).d Item discriminant validity scaling success = number of correlations of items with own scales higher than correlations with other scales/to-

tal number of correlations.e Internal-consistency reliability (Cronbach’s alpha).



cepts. A lower HR-QOL could be related either tothe impact of pharmacological treatments or to thepatient’s awareness about their HIV-positive sta-tus.To explain differences in mean scores in mental

health domains observed in patients in category A1compared with those in the category A2, we shouldconsider the great importance that patients usuallyattribute to the CD4+ count. As patients in groupA2 have lower counts, this may be seen as a nega-tive prognostic factor yielding a worse perceptionof general health. The better mean score of BP inpatients in category A1 when compared with thenormative sample is probably due to the young ageof the patients and the eligibility criteria of the sur-

vey (i.e. patients with co-existent acute or chronicdisease were not eligible). On the contrary, peoplerandomly sampled in the normative sample couldhave experienced diseases at the time of measure-ment. The differences between patients in catego-ries A1 and A2 could be explained by the fact thatindividuals in group A2 had had their diagnosis ofHIV-positivity for a longer period of time, receivedheavier treatments and, presumably, experiencedmore drug-related adverse events.The finding of a better SF-36 score in patients

with more severe disease is more difficult to inter-pret. Firstly, as the difference observed was not sta-tistically significant, it could be attributed to chance.Secondly, patients in group A2 may have received

Table VII. Mean differences between clinical categories (A1 and A2)

Scales A1-A2 (0-100 scale) p-Valuea A1-A2 (SD units)b

Physical functioning 2.1 0.334 0.14Role functioning physical 11.0 0.008 0.35Bodily pain 10.1 <0.001 0.48General health 9.2 0.005 0.41Vitality 3.7 0.177 0.19Social functioning –3.3 0.319 –0.14Role functioning emotional 4.7 0.380 0.13Mental health 0.3 0.924 0.02Physical component summary 4.0 <0.001 0.59Mental component summary –0.1 0.940 0.01a p-Values from 2-sided Student’s t-test.b Standard deviation (SD) of the whole sample.

Table VIII. Comparisons between clinical categories A1 and A2, and the Italian norm (mean values adjusted by gender and age)

Scales Italian norm Category A1 Category A2 p-Value foranalysis ofcovariance

Physical functioning 85.3 83.8 81.5 0.105Role functioning physical 79.1a 80.0 68.7a 0.006Bodily pain 74.4a 85.4a 75.0 <0.001General health 65.9a,b 53.9a,c 44.0b,c <0.001Vitality 62.3 62.5 58.3 0.099Social functioning 77.8 71.1 74.5 0.017Role functioning emotional 76.7 71.2 66.3 0.010Mental health 67.0a 61.3 60.2a <0.001Physical component summary 50.3a 51.5b 47.3a,b 0.001Mental component summary 46.8 43.8 43.8 0.002a, b and c identify pairs of mean values for each scale which are different at p < 0.01 (Scheffè).

70 Arpinelli et al.


more assistance and help from physicians, relativesand voluntary people, thus enhancing their qualityof social interactions.There are a few limitations of this study that

should be considered before generalising the pres-ent findings to other clinical and cultural settings.First, although the characteristics of the sample re-cruited and studied well represents the universe ofthe asymptomatic patients with HIV in Italy at thetime the present survey was carried out, the situa-tion may have changed. In addition, and more im-portantly, the case-mix in the present sample is quitedifferent from the one present in other countries,namely here most patients were male, relativelyyoung, with a history of drug abuse, and were notreceiving specific drugs for their disease. Second-ly, the study design only permitted the evaluationof the questionnaire validity and reliability and itwas not possible to test its responsiveness, a crucialcharacteristic of any instrument that is intended tobe used as evaluative tool.

Conclusion

In conclusion, our data demonstrates that theSF-36 health survey questionnaire maintains itspsychometric properties in the present sample ofItalian HIV-positive asymptomatic patients. Thisevidence should be considered important becauseit is the first application of the questionnaire insuch patients in Italy. In addition, although onlydata from sectional analyses were available, thefindings presented and discussed here provide fur-ther evidence regarding the validity, interpretabil-ity and robustness of this generic questionnaire insuch a setting, and may facilitate its utilisation infuture research projects.

Acknowledgements

This study was fully supported by funds from GlaxoWellcome Italy. Drs F. Arpinelli, G. Visonà and G. De Carliare employees of Glaxo Wellcome and Dr G. Apolone hasserved as a paid consultant toGlaxoWellcome for the presentstudy.This research was possible thanks to the following re-

searchers: Prof. F. Gritti, Bologna; Prof. B. De Rienzo,Modena; Dr L. Bonazzi, Reggio Emilia; Dr F. Alberici,

Piacenza; Dr S. Ranieri, Ravenna; Prof. G. Scalise, Ancona;Prof.ssa M. Montroni, Ancona; Prof.ssa A. Orani, Lecco;Prof. G. Fiori, Varese; Prof. G. Filice, Pavia; Prof. L.Minoli,Pavia; Dr G. Carnevale, Cremona; Dr A. Cantaluppi, Lodi;Prof.ssa L. Cremoni, Monza; Prof.ssa L. Caggese, Milano;Prof. F. Suter, Busto Arsizio; Prof.ssa A. Cargnel, Milano;Prof. G.Angarano, Bari; DrB.Grisorio, Foggia,DrP.Grima,Galatina; Prof. P.E. Manconi, Cagliari; Prof. A. Aceti, Sassari;Dr C. D’Amato, Roma; Dr F. Soscia, Latina; Dr P. Franci,Roma; Prof. S. D’Elia, Roma; Prof. P. Cadrobbi, Padova;Prof. E. Raise, Venezia; Prof. F. De Lalla, Vicenza; Prof. U.Tirelli, Aviano; Prof. A. Chirianni, Napoli; Prof. M. Piazza,Napoli; Prof. F. Piccinino, Napoli; Prof. A.Nunnari, Catania;Dr B. Celesia, Catania; Prof. V. Abbadessa, Palermo; Dr.ssaS. Mancuso, Palermo; Dr G. Cassola, Genova; Dr G. Or-ofino, Torino; Dr.ssa S. Belloro, Torino; Dr A. Sinicco,Torino; Prof. F. Rizzo,Genova; Dr.ssaM.L. Soranzo, Torino;Prof. M. Della Santa, Pisa; Dr F. Mazzotta, Bagno a Ripoli;Prof. S. Pauluzzi, Perugia; Dr F. Leoncini, Firenze; Prof. G.P.Carosi, Brescia; Dr G. Cadeo, Brescia; Dr A. Scalzini, Man-tova.

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Correspondence and offprints: Dr Fabio Arpinelli, MedicalDepartment, Glaxo Wellcome S.p.A., 2 via A. Fleming,37135 Verona, Italy.

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Health-Related Quality of Life in Asymptomatic Patients with HIV

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