Association between serum vitamin D status and health-related quality of life (HRQOL) in an older Korean population with radiographic knee osteoarthritis: data from the Korean national health and nutrition examination survey (2010–2011)

Table 2 Comparison of the EQ-5 Dimensions, EQ-VAS, and EQ-5D index according to vitamin D status

Health-related QOL		Vit. D deficiency (<10 ng/mL)	Vit. D normal (≥10 ng/mL)	P value
EQ-5Dimensions
Problem with mobility	None	43.9%	57.3%	0.007^†
Problem with mobility	Some or severe	56.1%	42.7%	0.007^†
Problem with self-care	None	80.7%	89.7%	0.014^†
Problem with self-care	Some or severe	19.3%	10.3%	0.014^†
Problem with usual activity	None	61.6%	75.6%	0.005^†
Problem with usual activity	Some or severe	38.4%	24.4%	0.005^†
Problem with pain/discomfort	None	59.2%	60.3%	0.827
Problem with pain/discomfort	Some or severe	40.8%	39.7%	0.827
Problem with depression/anxiety	None	79.1%	84.4%	0.273
Problem with depression/anxiety	Some or severe	20.9%	15.6%	0.273
EQ-VAS ^‡	Mean ± SE
1st quartile	38.90 ± 0.899	35.2%	22.9%	0.011^†
2nd quartile	62.40 ± 0.351	27.2%	28.9%
3rd quartile	78.13 ± 0.189	25.7%	22.6%
4th quartile	92.69 ± 0.295	11.9%	25.6%
EQ-5D index ^‡	Mean ± SE
1st quartile	0.62 ± 0.009	37.7%	23.3%	0.006^†
2nd quartile	0.84 ± 0.002	26.1%	26.9%
3rd quartile	0.91 ± 0.000	3.1%	6.1%
4th quartile	1.00 ± 0.000	33.1%	43.7%

Data are presented as weighted proportions unless otherwise indicated. Continuous results presented as weighted mean with standard error.
^†Statistically significant p-value ≤ 0.05. P-values were determined by chi-square test.
^‡The quartiles of EQ-VAS and EQ-5D index were defined as the following QOL classification: 1st quartile (poor), 2nd quartile (fair), 3rd quartile (good), 4th quartile (very good).
Abbreviation: EQ-5D, EuroQOL-5 dimension; EQ-VAS, EuroQOL-visual analogue scale; QOL, quality of life; SE, standard error; Vit. D, vitamin D.

ISSN: 1477-7525