Hyperventilation in asthma: a validation study of the Nijmegen Questionnaire--NQ

J Asthma. 2014 Oct;51(8):839-46. doi: 10.3109/02770903.2014.922190. Epub 2014 May 29.


Introduction: The Nijmegen questionnaire (NQ) has previously been used for screening the hyperventilation syndrome (HVS) in asthmatics. However, no validity study has been reported so far.

Objective: To examine the validity and reliability of the NQ in asthma patients and identify the prevalence of HVS.

Methods: The NQ (n = 162) was examined for translation, construct, cross-sectional and discriminant validity as well as for internal consistency and test-retest reliability.

Results: Principal component analysis and exploratory factor analysis revealed a single factor solution with 11 items and 58.6% of explained variability. These 11 NQ items showed high internal consistency (Cronbach's alpha = 0.92) and test-retest reliability (IR = 0.98). Higher NQ scores were found in the following subgroups: women versus men (p < 0.01); participants with moderate versus mild asthma (p < 0.001) or uncontrolled versus controlled asthma (p < 0.001), and participants with breath-hold time (BHT) < 30 versus ≥ 30 s (p < 0.01) or end-tidal CO2 (ETCO2) ≤ 35 versus >35 mmHg (p < 0.001). A cut-off score of >17 discriminated the participants with regard to the presence of HVS. The NQ showed 92.73% sensitivity and 91.59% specificity. The total NQ score was found significantly correlated with ETCO2 (r = -0.68), RR (r = 0.66) and BHT (r = -0.65). The prevalence of HVS was found 34%.

Conclusion: The NQ is a valid and reliable questionnaire for screening HVS in patients with stable mild-to-moderate asthma.

Keywords: Hyperventilation; Nijmegen questionnaire; reliability; validity.

Publication types

  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Asthma / complications*
  • Cross-Sectional Studies
  • Female
  • Humans
  • Hyperventilation / complications*
  • Hyperventilation / diagnosis*
  • Hyperventilation / epidemiology
  • Male
  • Middle Aged
  • Prevalence
  • Reproducibility of Results
  • Surveys and Questionnaires*
  • Young Adult