Development and testing of the modified version of the pulmonary functional status and dyspnea questionnaire (PFSDQ-M)

Heart Lung. 1998 May-Jun;27(3):159-68. doi: 10.1016/s0147-9563(98)90003-6.


Objective: Describe the process of development and testing to reduce the Pulmonary Functional Status and Dyspnea Questionnaire (PFSDQ) from 164 items to a modified questionnaire (the PFSDQ-M) consisting of 40 items.

Design: Instrument development and testing for reliability, validity, and practicality.

Setting: Hospital-based outpatients.

Patients: Testing was done on three groups of clinically stable patients with chronic obstructive pulmonary disease: a secondary analysis of 131 subjects for item selection, reliability, and validity; 50 additional subjects evaluating the PFSDQ-M for internal consistency, test-retest correlations, and construct validity; and 34 subjects from a longitudinal study for responsiveness.

Outcome measures: PFSDQ, PFSDQ-M, and spirometry.

Results: The practicality of the PFSDQ-M was supported by its sixth- to seventh-grade reading level, ease of reading (Flesch-Kincaid 69.5), self-administration, brief period for testing (7 minutes initially, 6 minutes on repeated testing), and limited missing data (< 8%). Reliability of the three components was supported by internal consistency alpha = 0.93 for change experienced by the patient with activities (CA), 0.95 for dyspnea with activities (DA), and 0.95 for fatigue with activities (FA). Good stability of the PFSDQ-M was demonstrated on test-retest; r = 0.70 for change, 0.83 for dyspnea, and 0.79 for fatigue (with activities). The usefulness of the PFSDQ-M in discriminating between dyspnea scores in patients based on their rate of deterioration in lung function was demonstrated.

Conclusions: The PFSDQ was modified by reducing the number of activities evaluated, standardizing scaling formats, and adding a fatigue component. Findings suggest that the PFSDQ-M demonstrates initial reliability; good validity estimates, as seen with the factor analysis, and the dyspnea and activity scores appear responsive to physiologic changes in lung function over time.

Publication types

  • Comparative Study

MeSH terms

  • Activities of Daily Living / classification
  • Aged
  • Ambulatory Care
  • Dyspnea / classification
  • Dyspnea / etiology*
  • Fatigue / classification
  • Fatigue / etiology
  • Female
  • Forced Expiratory Volume
  • Humans
  • Longitudinal Studies
  • Lung Diseases, Obstructive / classification
  • Lung Diseases, Obstructive / diagnosis*
  • Lung Diseases, Obstructive / rehabilitation
  • Male
  • Medical History Taking / statistics & numerical data*
  • Middle Aged
  • Reproducibility of Results
  • Spirometry / statistics & numerical data*
  • Surveys and Questionnaires