Quality of Life Research

, Volume 16, Issue 7, pp 1221–1230 | Cite as

Two questionnaires for Parkinson’s disease: are the PDQ-39 and PDQL equivalent?

  • Pablo Martinez-Martin
  • Marcos Serrano-Dueñas
  • Maria João Forjaz
  • Maria Soledad Serrano



Although there is a wide range of specific health-related quality of life (HRQoL) measures for Parkinson’s disease (PD), their psychometric attributes have never been compared.


To compare the psychometric characteristics of the Parkinson’s Disease Questionnaire-39 items (PDQ-39) and Parkinson’s Disease Quality of Life Questionnaire (PDQL).


The PDQ-39 and PDQL were simultaneously applied to 187 PD patients. Additional assessments included Hoehn and Yahr staging, Schwab and England Scale (SES), Unified Parkinson’s Disease Rating Scale, Pfeiffer’s Short Portable Mental Status Questionnaire (SPMSQ) and Hospital Anxiety and Depression Scale (HADS). Criteria for acceptability, scaling assumptions, reliability, construct validity and precision were drawn up.


Both the PDQ-39 and PDQL proved very similar in the following aspects: acceptability (no floor or ceiling effect); scaling assumptions (79.5% and 80% respectively of item-total correlations fitted the standard); internal consistency (PDQ-39 domains, α = 0.43–0.93; PDQL domains, α = 0.70–0.88); stability (intraclass correlation coefficient = 0.76–0.90); and internal validity (PDQ-39, r = 0.09–0.70; PDQL, r = 0.52–0.71). Convergent validity between the two questionnaires was moderate to high (r = −0.91 for summary indices). Precision was higher for the PDQ-39 Summary Index, and predictors were the same for both measures (mood disorders and disability).


Although the psychometric properties tested are quite similar in both measures, mainly insofar as summary indices are concerned, differences in some attributes and structural content should nevertheless be considered when comparing both instruments.


Parkinson’s disease PDQ-39 PDQL Psychometric attributes Convergent validity 



Activities of daily living


Hospital Anxiety and Depression Scale, Anxiety subscale


Hospital Anxiety and Depression Scale, Depression subscale


Health-related quality of life


Hoehn and Yahr scale


Intraclass correlation coefficient


Parkinson’s disease


Parkinson’s Disease Questionnaire-39 items


Parkinson’s Disease Questionnaire-39 items, Summary Index


Parkinson’s Disease Quality of Life Questionnaire


Parkinson’s Disease Quality of Life Questionnaire, Summary Index


Standard error of measurement


Schwab and England Scale


Pfeiffer’s Short Portable Mental Status Questionnaire


Unified Parkinson’s Disease Rating Scale



This study was partially funded by a grant awarded by the Ramón y Cajal Research Fellowship Programme (Spanish Ministry of Education & Science) to Maria João Forjaz. C. Rodriguez-Blazquez helped with management of data and editorial work.


  1. 1.
    Shindler, J. S., Brown, R., Welburn, P., & Parkes, J. D. (1993). Measuring the quality of life of patients with Parkinson’s disease. In S. R. Walker & R. M. Rosser (Eds.), Quality of life assessment: Key issues in the 1990s (pp. 289–300). Dordrecht: Kluwer.Google Scholar
  2. 2.
    Martínez-Martín, P., & Koller, W. C. (Eds.) (1999). Quality of life in Parkinson’s disease. Barcelona: Masson SA.Google Scholar
  3. 3.
    Spilker, B. (Ed.) (1996). Quality of life and pharmacoeconomics in clinical trials (2nd ed.). Philadelphia: Lippincot-Raven Publishers.Google Scholar
  4. 4.
    Peto, V., Fitzpatrick, R., & Jenkinson, C. (1997). Self-reported health status and access to health services in a community sample with Parkinson’s disease. Disability and Rehabilitation, 19, 97–103.PubMedCrossRefGoogle Scholar
  5. 5.
    Karlsen, K. H., Tandberg, E., Arsland, D., & Larsen, J. P. (2000). Health related quality of life in Parkinson’s disease: A prospective longitudinal study. Journal of Neurology, Neurosurgery, and Psychiatry, 69, 584–589.PubMedCrossRefGoogle Scholar
  6. 6.
    Chapuis, S., Ouchchane, L., Metz, O., Gerbaud, L., & Durif, F. (2005). Impact of the motor complications of Parkinson’s disease on the quality of life. Movement Disorders, 20, 224–230.PubMedCrossRefGoogle Scholar
  7. 7.
    Noyes, K., Dick, A. W., & Holloway, R. G. (2006). The Parkinson study group. Pramipexole versus levodopa in patients with early Parkinson’s disease: Effect on generic and disease-specific quality of life. Value in Health, 9, 28–38.PubMedCrossRefGoogle Scholar
  8. 8.
    Biglan, K. M., Schwid, S., Eberly, S., Blindauer, K., Fahn, S., Goren, T., et al. (2006). Rasagiline improves quality of life in patients with early Parkinson’s disease. Movement Disorders, 21, 616–623.PubMedCrossRefGoogle Scholar
  9. 9.
    Siderowf, A., Jaggi, J. L., Xie, S. X., Loveland-Jones, C., Leng, L., Hurtig, H., et al. (2006). Long-term effects of bilateral subthalamic nucleus stimulation on health-related quality of life in advanced Parkinson’s disease. Movement Disorders, 21, 746–753.PubMedCrossRefGoogle Scholar
  10. 10.
    Deuschl, G., Schade-Brittinger, C., Krak, P., Volkmann, J., Schater, H., Bötzel, K., et al. (2006). A randomized trial of deep-brain stimulation for Parkinson’s disease. The New England Journal of Medicine, 355, 896–908.PubMedCrossRefGoogle Scholar
  11. 11.
    Marinus, J., Ramaker, C., van Hilten, J. J., & Stiggelbout A. M. (2002). Health-related quality of life in Parkinson’s disease: A systematic review of disease-specific instruments. Journal of Neurology, Neurosurgery, and Psychiatry, 72, 241–248.PubMedCrossRefGoogle Scholar
  12. 12.
    Martinez-Martin, P., & Cubo E. Scales to measure Parkinsonism. In W. C. Koller & E. Melamed (Eds.), Parkinson’s disease and related disorders. Handbook of clinical neurology (vol. 83, 3rd series). Elsevier BV (in press).Google Scholar
  13. 13.
    Peto, V., Jenkinson, C., Fitzpatrick, R., & Greenhall, R. (1995). The development and validation of a short measure of functioning and well being for individuals with Parkinson’s disease. Quality of Life Research, 4, 241–248.PubMedCrossRefGoogle Scholar
  14. 14.
    de Boer, A. G. E. M., Wijker, W., Speelman, J. D., & de Haes, J. C. J. M. (1996). Quality of life in patients with Parkinson’s disease: Development of a questionnaire. Journal of Neurology, Neurosurgery, and Psychiatry, 61, 70–74.PubMedGoogle Scholar
  15. 15.
    Jenkinson, C., Fitzpatrick, R., Norquist, J., Findley, L., & Hughes, K. (2003). Cross-cultural evaluation of the Parkinson’s disease questionnaire: Tests of data quality, score reliability, response rate, scaling assumptions in the United States, Canada, Japan, Italy, and Spain. Journal of Clinical Epidemiology, 56, 843–847.PubMedCrossRefGoogle Scholar
  16. 16.
    Gibb W. R. G., & Lees, A. J. (1988). The relevance of the Lewy body to the pathogenesis of idiopathic Parkinson’s disease. Journal of Neurology, Neurosurgery, and Psychiatry, 51, 745–752.PubMedGoogle Scholar
  17. 17.
    Hoehn, M. M., & Yahr, M. D. (1967). Parkinsonism: Onset, progression, and mortality. Neurology, 17, 427–442.PubMedCrossRefGoogle Scholar
  18. 18.
    Schwab, R. S., & England A. C. (1969). Projection technique for evaluating surgery in Parkinson’s disease. In F. J. Gillingham & I. M. L. Donaldson (Eds.), Third symposium on Parkinson’s disease (pp. 152–157). Edinburgh: E and S Livingstone.Google Scholar
  19. 19.
    Fahn, S., Elton, R. L., & Members of The UPDRS Development Committee (1987). Unified Parkinson’s disease rating scale. In S. Fahn, C. D. Marsden, M. Goldstein, & D. B. Calne (Eds.), Recent development in Parkinson’s disease (vol. 2, pp. 153–163). New Jersey: McMillan.Google Scholar
  20. 20.
    Pfeiffer, E. (1975). A short portable mental status questionnaire for the assessment of organic brain deficit in elderly patients. Journal of the American Geriatrics Society, 23, 433–441.PubMedGoogle Scholar
  21. 21.
    Zigmond, A. S., & Snaith, R. P. (1983). The hospital anxiety and depression scale. Acta Psychiatrica Scandinavica, 67, 361–370.PubMedCrossRefGoogle Scholar
  22. 22.
    Goetz, C. G., Poewe, W., Rascol, O., Sampaio, C., Stebbins, G. T., Counsell, C., et al. (2004). Movement disorder society task force report on the Hoehn and Yahr staging scale: Status and recommendations. Movement Disorders, 19, 1020–1028.PubMedCrossRefGoogle Scholar
  23. 23.
    Movement Disorder Society Task Force on Rating Scales for Parkinson’s Disease (2003). The Unified Parkinson’s Disease Rating Scale (UPDRS): Status and recommendations. Movement Disorders, 18, 738–750.Google Scholar
  24. 24.
    Marinus, L., Leentjens, A. F. G., Visser, M., Stiggelbout, A. M., & van Hilten, J. J. (2002). Evaluation of the hospital anxiety and depression scale in patients with Parkinson’s disease. Clinical Neuropharmacology, 5, 318–324.CrossRefGoogle Scholar
  25. 25.
    Serrano-Dueñas, M., Martínez-Martín, P., & Vaca-Baquero, V. (2004). Validation and Cross cultural adjustment of PDQL-Questionnaire Spanish version (Ecuador) (PDQL-EV). Parkinsonism & Related Disorders, 10, 433–437.CrossRefGoogle Scholar
  26. 26.
    Martínez-Martín, P., Serrano-Dueñas, M., & Vaca-Baquero, V. (2005). Psychometric characteristics of the Parkinson’s Disease Questionnaire (PDQ-39)—Ecuadorian version. Parkinsonism & Related Disorders, 11, 297–304.CrossRefGoogle Scholar
  27. 27.
    Ware, J. E., Jr., Davies-Avery, A., & Donald, C. A. (1978). Conceptualization and measurement of health for adults in the health insurance study, Volume V: General health perceptions. Santa Monica, CA: The Rand Corporation.Google Scholar
  28. 28.
    Eisen, M., Ware, J. E., Jr., Donald, C. A., & Brook, R. H. (1979). Measuring components of children’s health status. Medical Care, 17, 902–21.PubMedCrossRefGoogle Scholar
  29. 29.
    McHorney, C. A., & Tarlov, A. R. (1995). Individual-patient monitoring in clinical practice: Are available health status surveys adequate? Quality of Life Research, 4, 293–307.PubMedCrossRefGoogle Scholar
  30. 30.
    Holmes, W., Bix, B., & Shea, J. (1996). SF-20 score and item distributions in a human immunodeficiency virus-seropositive sample. Medical Care, 34, 562–569.PubMedCrossRefGoogle Scholar
  31. 31.
    Chassany, O., Sagnier, P., Marquis, P., Fullerton, S., & Aaronson, N. (2002). Patient-reported outcomes: The example of health-related quality of life—a European guidance document for the improved integration of health-related quality of life assessment in the drug regulatory process. Drug Information Journal, 36, 209–238.Google Scholar
  32. 32.
    Fayers, P., & Machin, D. (2000). Quality of life: Assessment, analysis and interpretation (pp. 45–90). Chichester, United Kingdom: John Wiley & Sons. .Google Scholar
  33. 33.
    Scientific Advisory Committee of the Medical Outcomes Trust. (2002). Assessing health status and quality-of-life instruments: Attributes and review criteria. Quality of Life Research, 11, 193–205.CrossRefGoogle Scholar
  34. 34.
    Ware, J. E., Jr., & Gandek, B. (1998). Methods for testing data quality, scaling assumptions, and reliability: The IQOLA project approach. International quality of life assessment. Journal of Clinical Epidemiology, 5, 945–952.CrossRefGoogle Scholar
  35. 35.
    Landis, J. R., & Koch, G. G. (1977). The measurement of observer agreement for categorical data. Biometrics, 33, 159–174.PubMedCrossRefGoogle Scholar
  36. 36.
    Fisk, J. D., Brown, M. G., Sketris, I. S., Metz, L. M., Murray, T. J., & Stadnyk, K. J. (2005). A comparison of health utility measures for the evaluation of multiple sclerosis treatments. Journal of Neurology, Neurosurgery, and Psychiatry, 76, 58–63.PubMedCrossRefGoogle Scholar
  37. 37.
    van der Linden, F. A. H., Kragt, J. J., Klein, M., van der Ploeg, H. M., & Polman, C. H. (2005). Uitdehaag BMJ. Psychometric evaluation of the multiple sclerosis impact scale (MSIS-29) for proxy use. Journal of Neurology, Neurosurgery, and Psychiatry, 76, 1677–1681.PubMedCrossRefGoogle Scholar
  38. 38.
    Beaton, D. E., Bombardier, C., Katz, J. N., & Wright, J. G. (2001). A taxonomy for responsiveness. Journal of Clinical Epidemiology, 54, 1204–1217.PubMedCrossRefGoogle Scholar
  39. 39.
    Sloan, J. A., Cella, D., & Hays, R. D. (2005). RAND. Clinical significance of patient-reported questionnaire data: Another step toward consensus. Journal of Clinical Epidemiology, 58, 1217–1219.PubMedCrossRefGoogle Scholar
  40. 40.
    Hobson, P., Holden, A., & Meara, J. (1999). Measuring the impact of Parkinson’s disease with the Parkinson’s disease quality of life questionnaire. Age and Ageing, 28, 341–346.PubMedCrossRefGoogle Scholar
  41. 41.
    Jenkinson, C., Fitzpatrick, R., & Peto, V. (1999). Health-related quality-of-life measurement in patients with Parkinson’s disease. Pharmacoeconomics, 15, 157–165.PubMedCrossRefGoogle Scholar
  42. 42.
    Hagell, P., Whalley, D., McKenna, S. P., & Lindvall, O. (2003). Health status measurement in Parkinson’s disease: Validity of the PDQ-39 and Nottingham Health Profile. Movement Disorders, 18, 773–783.PubMedCrossRefGoogle Scholar
  43. 43.
    Reuther, M., Spottke, E. A., Klotsche, J., Riedel, O., Peter, H., Berger, K., et al. (2007). Assessing health-related quality of life in patients with Parkinson’s disease in a prospective longitudinal study. Parkinsonism & Related Disorders, 13, 108–114.CrossRefGoogle Scholar
  44. 44.
    Martinez-Martin, P., & Deuschl, G. (2007). The effect of medical and surgical interventions on health-related quality of life in Parkinson’s disease. Movement Disorders, 22, 757–765.PubMedCrossRefGoogle Scholar
  45. 45.
    Damiano, A. M., Snyder, C., Strausser, B., & Willian, M. K. (1999). A review of health-related quality of life concepts and measures for Parkinson’s disease. Quality of Life Research, 8, 235–243.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  • Pablo Martinez-Martin
    • 1
  • Marcos Serrano-Dueñas
    • 2
    • 3
  • Maria João Forjaz
    • 1
  • Maria Soledad Serrano
    • 3
  1. 1.Neuroepidemiology UnitNational Centre for Epidemiology, Carlos III Institute of HealthMadridSpain
  2. 2.Movement Disorders Unit, Department of NeurologyCarlos Andrade Marín HospitalQuitoEcuador
  3. 3.School of MedicinePontifical Catholic University of EcuadorQuitoEcuador

Personalised recommendations