General or disease specific questionnaire? A comparative study in hemodialysis patients.
OBJECTIVE
Today questionnaires developed to assess important outcome measures such as health-related quality of life are widely used. In this study we evaluated the construct validity of the Nottingham Health Profile (NHP) and the reliability of its Turkish version in hemodialysis patients.


METHODS
In a sample of patients on renal dialysis (n = 94) the quality of life is measured by the NHP. The validity of this questionnaire is evaluated by using the Kidney Disease Questionnaire (KDQ) in the same patient group. The NHP is administered twice to each patient, at dialysis intervals two weeks apart.


RESULTS
NHP scores at both administrations are similar in both assessments. Pearson's correlation coefficients range from 0.61 to 0.84. Cronbach's alpha coefficients for the NHP sections range between 0.64 and 0.79. The alpha coefficients for three of the NHP scales (energy, sleep and social isolation) are well below 0.7. In the KDQ the mean values obtained for the five dimensions are: 4.2 +/- 1.5 for physical symptoms, 4.8 +/- 1.7 for fatigue, 4.9 +/- 1.9 for depression, 4.2 +/- 1.2 for relationship with others, and 4.8 +/- 1.5 for frustration. In general the correlation between the dimensions of the NHP and KDQ is good and the correlation coefficients varies from 0.18 to 0.73. Clinical validity is assessed by examining the correlation between the results obtained for the two questionnaires (components of the NHP and KDQ) and hemoglobin level, number of the co-morbid conditions and educational level.


CONCLUSIONS
The NHP is shown to have construct validity when used in patients with end-stage renal disease (ESRD) in Turkey. The application of the NHP in patients with ESRD is easy, fast and the questions are not difficult to understand. The multiple-degree scoring in the KDQ causes a complexity in answering. The correlation between the dimensions of the NHP and KDQ is good. Our results show better correlations between disease specific questionnaires and clinical parameters.
Kutlay
Sim
S
Department of Nephrology, Ankara, Turkey. skutlay@hotmail.com
Nergizoglu
Gokhan
G
Kutlay
Sehim
S
Keven
Kenan
K
Erturk
Sehsuvar
S
Ates
Kenan
K
Duman
Neval
N
Karatan
Oktay
O
Atli
Teslime
T
D000328:Adult; D015415:Biomarkers / Q000097:blood; D015897:Comorbidity; D032882:Comprehension / Q000502:physiology; D003863:Depression / Q000097:blood / Q000453:epidemiology / Q000523:psychology; D004522:Educational Status; D005221:Fatigue / Q000097:blood / Q000453:epidemiology / Q000523:psychology; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000453:epidemiology / Q000523:psychology; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D006435:Renal Dialysis; D015203:Reproducibility of Results; D013223:Statistics as Topic; D011795:Surveys and Questionnaires
D015415:Biomarkers; D006454:Hemoglobins