Validation of the Polish version of Diabetes Quality of Life - Brief Clinical Inventory (DQL-BCI) among patients with type 2 diabetes.
BACKGROUND
The aim of the study was to develop a Polish version of the Diabetes Quality of Life Brief Clinical Inventory (DQL-BCI) and to perform validating evaluation of selected psychometric aspects.


METHODS
The translation process was performed in accordance with generally accepted international principles of translation and cultural adaptation of measurement tools. Two hundred and seventy-four subjects with type 2 diabetes completed the Polish version of DQL-BCI, the generic EQ-5D questionnaire and the diabetes-specific DSC-R. The examination provides information about the reliability (internal consistency, test-retest) and the construct validity of the studied tool (the relationship between the DQL-BCI score and EQ-5D and DSC-R scales, as well as selected clinical patient characteristics).


RESULTS
Cronbach's α (internal consistency) for the translated version of DQL-BCI was 0.76. Test-retest Pearson correlation coefficient was 0.96. Spearman's coefficient correlation between DQL-BCI score and EQ-5D index and EQ-VAS were 0.6 (p = 0.0000001) and 0.61 (p = 0.0000001) respectively. The correlation between scores of the examined tool and DSC-R total score was -0.6 (p = 0.0000001). Quality of life was lower among patients with microvascular as well as macrovascular complications and with occurring hypoglycemic episodes.


CONCLUSIONS
The result of this study is the Polish scale used to test the quality of life of patients with diabetes, which includes the range of problems faced by patients while maintaining a patient-friendly form. High reliability of the scale and good construct validity qualify the Polish version of DQL-BCI as a reliable tool in both research and individual diagnostics.
Department of Endocrinology, Medical University of Lublin, Lublin, Poland ; Chair of Internal Medicine and Department of Internal Medicine in Nursing, Medical University of Lublin, Lublin, Poland.
Marta
M
Dudzińska
Department of Endocrinology, Medical University of Lublin, Lublin, Poland.
Jerzy S
JS
Tarach
Saint Louis University Center for Outcomes Research, Saint Louis, USA.
Thomas E
TE
Burroughs
Department of Endocrinology, Medical University of Lublin, Lublin, Poland ; Chair of Internal Medicine and Department of Internal Medicine in Nursing, Medical University of Lublin, Lublin, Poland.
Agnieszka
A
Zwolak
Department of Endocrinology, Medical University of Lublin, Lublin, Poland.
Beata
B
Matuszek
Department of Mathematics and Medical Biostatistics, Medical University of Lublin, Lublin, Poland.
Agata
A
Smoleń
Department of Endocrinology, Medical University of Lublin, Lublin, Poland.
Andrzej
A
Nowakowski
psychometric evaluation; quality of life; reliability; type 2 diabetes; validity