Knee osteoarthritis in two ethnic groups in southern Israel: Risk factors and the role of Muslim prayer

Table 1 Patient characteristics (n = 353), n (%)/mean ± SD

Variable	Bedouins (n = 171)	Jews (n = 182)	Total (n = 353)	P value
Age	61.0 ± 6.7	63.1 ± 7.1	62.1 ± 7.3	0.009
Sex male subjects	80 (47)	102 (56)	182 (52)	0.082
Number of children	8.3 ± 4.0	4.2 ± 2.1	6.1 ± 3.8	< 0.001
BMI	28.3 ± 4.3	27.1 ± 5.1	27.6 ± 4.8	0.015
Knee pain	74 (43)	107 (59)	181 (51)	0.004
Diagnosed with OAK	51 (30)	53 (29)	104 (29)	0.885
Diabetes	79 (46)	71 (39)	150 (42)	0.172
Knee trauma	11 (6)	36 (20)	47 (13)	< 0.001
Arthroscopic surgery	10 (6)	13 (7)	23 (7)	0.622
Knee replacement surgery	12 (7)	13 (7)	25 (7)	0.963
Active in sports	7 (4)	42 (23)	49 (14)	< 0.001
Years active in sports	7.8 ± 4.2	7.8 ± 4.9	7.8 ± 4.8	0.484
Missing	1	2	3
Hours of weekly sports	1.7 ± 1.3	2.3 ± 1.2	2.2 ± 1.2	0.221
Type of sport
Bicycle riding	0	5 (11)	5 (10)	< 0.001
Walking/running	6 (86)	31 (74)	37 (76)	< 0.001
Fitness room	0	1 (2)	1 (2)	< 0.001
Swimming	0	2 (5)	2 (4)	< 0.001
Missing	1 (14)	3 (7)	4 (8)

BMI: Body mass index; OAK: Osteoarthritis of knees.

Table 2 Multivariate models for knee osteoarthritis in the two ethnic populations

Variable	Bedouins		Jews
	OR (95%CI)	P value	OR (95%CI)	P value
Age	1.05 (0.97-1.14)	0.221	1.03 (0.98-1.08)	0.299
Sex (male subjects)	0.69 (0.23-2.01)	0.491	0.50 (0.23-1.10)	0.082
Number of children	1.13 (0.97-1.31)	0.113	0.93 (0.76-1.12)	0.424
BMI	1. 19 (1.05-1.36)	0.008	1.18 (1.08-1.29)	< 0 .001
Diabetes mellitus (yes)	2.03 (0.74-5.53)	0.167	2.64 (1.18-5.92)	0.019
Physically active (yes)	-	-	0.18 (0.04-0.85)	0.031
Pray on their knees (yes)	0.05 (0.02-0.12)	< 0.001	-	-

Hosmer-Lemeshow goodness-of-fit test demonstrated adequate model fit for both logistic regression models (Jews: P = 0.525; Bedouins: P = 0.872). BMI: Body mass index; OR: Odds ratio; CI: Confidence interval.

Table 3 Comparison of osteoarthritis of knees severity between the two ethnic sectors and between worshipers and non-worshipers in the Bedouin ethnic group

	Diagnosed with OAK			Bedouins diagnosed with OAK
	Jews (n = 53)	Bedouins (n = 51)	P value	Pray (n = 11)	Do not pray (n = 39)	P value
Level of pain median (IQR)	10.0 (5.0-13.0)	10.0 (8.0-14.0)	0.315	5.0 (4.0-8.0)	12.5 (10.0-14.0)	< 0.001
Level of rigidity median (IQR)	4.0 (2.0-5.0)	4.0 (4.0-6.0)	0.218	2.0 (2.0-4.0)	4.0 (4.0-6.0)	< 0.001
Functional level median (IQR)	33.0 (26.0-48.5)	36.0 (28.0-47.0)	0.682	17.0 (13.0-28.0)	44.0 (33.0-49.8)	< 0.001
Total score median (IQR)	46.0 (35.0-67.0)	50.0 (40.0-66.0)	0.725	24.0 (19.0-40.0)	61.0 (43.3-70.0)	< 0.001
Disease severity, n (%)			0.698			< 0.001
Minimal	5 (9.43)	2 (3.92)		1 (9.09)	1 (2.56)
Mild	13 (24.53)	15 (29.41)		9 (81.82)	6 (15.38)
Moderate	22 (41.51)	22 (43.14)		1 (9.09)	20 (51.28)
Severe/very severe	13 (24.53)	12 (23.53)		0	12 (30.77)

IQR: Interquartile range; OAK: Osteoarthritis of knees.