Comparing a disease-specific and a generic health-related quality of life instrument in subjects with asthma from the general population

Milo A Puhan, Jean-Michel Gaspoz, Pierre-Olivier Bridevaux, Christian Schindler, Ursula Ackermann-Liebrich, Thierry Rochat, Margaret W Gerbase, Milo A Puhan, Jean-Michel Gaspoz, Pierre-Olivier Bridevaux, Christian Schindler, Ursula Ackermann-Liebrich, Thierry Rochat, Margaret W Gerbase

Abstract

Background: Few epidemiologic studies have assessed health-related quality of life (HRQL) of asthma patients from a general population and it is unclear which instrument is best suitable for this purpose. We investigated the validity of the Asthma Quality of Life Questionnaire (AQLQ) and the SF-36 completed by individuals with asthma from the population-based SAPALDIA (Swiss study on air pollution and lung diseases in adults) cohort.

Methods: The study included 258 participants with a physician-diagnosed asthma who had completed the AQLQ and SF-36. We assessed floor and ceiling effects, internal consistency reliability and cross-sectional validity with a priori hypotheses that correlations between the specific HRQL domains (e.g. "symptoms" or "physical functioning") and the corresponding external validation measures (respiratory symptoms, need for doctor visits, limitation in activities due to asthma and lung function) would capture similar aspects and be correlated moderately (> or = 0.3) to strongly (> or = 0.5), whereas non-corresponding domains be correlated weakly with each other (<0.3).

Results: The AQLQ showed pronounced ceiling effects with all median domain scores above 6 (scores varied from 1-7). For the SF-36, ceiling effects were present in 5 out of 8 domains. Cronbach's alpha was >0.7 for all AQLQ and SF-36 domains. Correlations between the AQLQ domains "respiratory symptoms", "activity limitation" and "environmental exposure", and the validation measures ranged from 0.29-0.57. Correlations between the "emotional function" domain and the validation measures were also in this range (0.31-0.55) and not as low as we hypothesized. For the SF-36, correlations between "physical functioning" and "role physical", and the validation measures ranged from 0.25-0.56, whereas "role emotional" and "mental health" correlated with these measures from 0.01-0.23.

Conclusion: The AQLQ and the SF-36 showed fairly good internal consistency. Both instruments are limited by ceiling effects, but they appear less pronounced in the SF-36, which also shows a better discrimination between different aspects of HRQL. The SF-36 may therefore be a more valid measure of HRQL than the AQLQ when applied to individuals with asthma from the general population.

Figures

Figure 1
Figure 1
Distribution of AQLQ and SF-36 domain scores. The figure shows the distributions of the respondents' AQLQ (Likert type scale from 1 to 7) and SF-36 scores (from 0 to 100). For the AQLQ all domain scores are left-skewed. For the SF-36, the "physical functioning", "role physical", "bodily pain", "social functioning" and "role emotional" domains are left-skewed. The "general health", "vitality" and "mental health" domains showed almost normal distributions.

References

    1. Jenkins CR, Thien FC, Wheatley JR, Reddel HK. Traditional and patient-centred outcomes with three classes of asthma medication. Eur Respir J. 2005;26:36–44. doi: 10.1183/09031936.05.00144704.
    1. Guyatt GH, Feeny DH, Patrick DL. Measuring health-related quality of life. Ann Intern Med. 1993;118:622–629.
    1. Adams N, Bestall J, Jones PW. Budesonide for chronic asthma in children and adults. Cochrane Database Syst Rev. 2001:CD003274.
    1. Adams NP, Bestall JB, Malouf R, Lasserson TJ, Jones PW. Inhaled beclomethasone versus placebo for chronic asthma. Cochrane Database Syst Rev. 2005:CD002738.
    1. Adams NP, Bestall JC, Lasserson TJ, Jones PW, Cates C. Fluticasone versus placebo for chronic asthma in adults and children. Cochrane Database Syst Rev. 2005:CD003135.
    1. Travers J, Marsh S, Williams M, Weatherall M, Caldwell B, Shirtcliffe P, Aldington S, Beasley R. External validity of randomised controlled trials in asthma: to whom do the results of the trials apply? Thorax. 2007;62:219–223.
    1. Benson K, Hartz AJ. A comparison of observational studies and randomized, controlled trials. N Engl J Med. 2000;342:1878–1886. doi: 10.1056/NEJM200006223422506.
    1. Concato J. Observational versus experimental studies: what's the evidence for a hierarchy? NeuroRx. 2004;1:341–347. doi: 10.1602/neurorx.1.3.341.
    1. Concato J, Horwitz RI. Beyond randomised versus observational studies. Lancet. 2004;363:1660–1661. doi: 10.1016/S0140-6736(04)16285-5.
    1. Juniper EF, Guyatt GH, Epstein RS, Ferrie PJ, Jaeschke R, Hiller TK. Evaluation of impairment of health related quality of life in asthma: development of a questionnaire for use in clinical trials. Thorax. 1992;47:76–83.
    1. Guyatt GH, King DR, Feeny DH, Stubbing D, Goldstein RS. Generic and specific measurement of health-related quality of life in a clinical trial of respiratory rehabilitation. JClinEpidemiol. 1999;52:187–192.
    1. Puhan MA, Guyatt GH, Goldstein R, Mador J, McKim D, Stahl E, Griffith L, Schunemann HJ. Relative responsiveness of the Chronic Respiratory Questionnaire, St. Georges Respiratory Questionnaire and four other health-related quality of life instruments for patients with chronic lung disease. Respiratory medicine. 2007;101:308–316. doi: 10.1016/j.rmed.2006.04.023.
    1. Ware JE, Jr., Sherbourne CD. The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection 1. Med Care. 1992;30:473–483. doi: 10.1097/00005650-199206000-00002.
    1. Ackermann-Liebrich U, Kuna-Dibbert B, Probst-Hensch NM, Schindler C, Felber Dietrich D, Stutz EZ, Bayer-Oglesby L, Baum F, Brandli O, Brutsche M, Downs SH, Keidel D, Gerbase MW, Imboden M, Keller R, Knopfli B, Kunzli N, Nicod L, Pons M, Staedele P, Tschopp JM, Zellweger JP, Leuenberger P. Follow-up of the Swiss Cohort Study on Air Pollution and Lung Diseases in Adults (SAPALDIA 2) 1991-2003: methods and characterization of participants. Soz Praventivmed. 2005;50:245–263. doi: 10.1007/s00038-005-4075-5.
    1. Martin BW, Ackermann-Liebrich U, Leuenberger P, Kunzli N, Stutz EZ, Keller R, Zellweger JP, Wuthrich B, Monn C, Blaser K, Bolognini G, Bongard JP, Brandli O, Braun P, Defila C, Domenighetti G, Grize L, Karrer W, Keller-Wossidlo H, Medici TC, Peeters A, Perruchoud AP, Schindler C, Schoeni MH, Villiger B, et al. SAPALDIA: methods and participation in the cross-sectional part of the Swiss Study on Air Pollution and Lung Diseases in Adults. Soz Praventivmed. 1997;42:67–84. doi: 10.1007/BF01318136.
    1. Burney PG, Luczynska C, Chinn S, Jarvis D. The European Community Respiratory Health Survey. Eur Respir J. 1994;7:954–960.
    1. Global Initiative for Asthma
    1. Bonii G, Rezzani C, Grassi M, Marinoni A. ECRHS screening questionnaire scoring : a methodological suggestion for asthma assessment. J Outcome Meas. 2001;4:740–762.
    1. Lurie A, Marsala C, Hartley S, Bouchon-Meunier B, Dusser D. Patients' perception of asthma severity. Respiratory medicine. 2007;101:2145–2152. doi: 10.1016/j.rmed.2007.05.027.
    1. Sunyer J, Pekkanen J, Garcia-Esteban R, Svanes C, Kunzli N, Janson C, de Marco R, Anto JM, Burney P. Asthma score: predictive ability and risk factors. Allergy. 2007;62:142–148. doi: 10.1111/j.1398-9995.2006.01184.x.
    1. Streiner DN., G . Health measurement scales. Secondth edition. Oxford , Oxford University Press;; 1998. pp. 60–65.
    1. Terwee CB, Dekker FW, Wiersinga WM, Prummel MF, Bossuyt PM. On assessing responsiveness of health-related quality of life instruments: guidelines for instrument evaluation. Qual Life Res. 2003;12:349–362. doi: 10.1023/A:1023499322593.
    1. Aburuz S, Gamble J, Heaney LG. Assessment of impairment in health-related quality of life in patients with difficult asthma: Psychometric performance of the Asthma Quality of Life Questionnaire. Respirology. 2007;12:227–233. doi: 10.1111/j.1440-1843.2006.01020.x.
    1. Juniper EF, Buist AS, Cox FM, Ferrie PJ, King DR. Validation of a standardized version of the Asthma Quality of Life Questionnaire. Chest. 1999;115:1265–1270. doi: 10.1378/chest.115.5.1265.
    1. Leidy NK, Coughlin C. Psychometric performance of the Asthma Quality of Life Questionnaire in a US sample. Qual Life Res. 1998;7:127–134. doi: 10.1023/A:1008853325724.
    1. Sanjuas C, Alonso J, Prieto L, Ferrer M, Broquetas JM, Anto JM. Health-related quality of life in asthma: a comparison between the St George's Respiratory Questionnaire and the Asthma Quality of Life Questionnaire. Qual Life Res. 2002;11:729–738. doi: 10.1023/A:1020897816228.
    1. Puhan MA, Behnke M, Frey M, Grueter T, Brandli O, Lichtenschopf A, Guyatt GH, Schunemann HJ. Self-administration and interviewer-administration of the German Chronic Respiratory Questionnaire: instrument development and assessment of validity and reliability in two randomised studies. Health QualLife Outcomes. 2004;2:1. doi: 10.1186/1477-7525-2-1.
    1. Schunemann HJ, Griffith L, Jaeschke R, Goldstein R, Stubbing D, Austin P, Guyatt GH. A Comparison of the Original Chronic Respiratory Questionnaire With a Standardized Version. Chest. 2003;124:1421–1429. doi: 10.1378/chest.124.4.1421.
    1. Schunemann HJG., R;Mador,MJ;McKim,D;Stahl,E;Puhan;MA;Griffith,L;Grant,B;Austin,P;Collins,R;Guyatt,GH A Randomized Trial to Evaluate the Self-Administered Standardized CRQ. Europ Respir J. 2005;25

Source: PubMed

Sponsors en medewerkers

Medische omstandigheden

Geneesmiddelinterventies

3
Abonneren