Development and psychometric evaluation of the Chronic Kidney Disease Screening Index

Figures & data

Table 1. Participants' responses to the knowledge subscale.

Items I know that:	Responding “Yes” N (%)	Responding “No” N (%)	Responding “Unsure” N (%)
(K 1) The kidneys regulate body water and chemicals in my blood such as sodium, potassium, phosphorus, and calcium.	616 (83.2)	103 (13.9)	21 (2.8)
(K 2) The kidneys remove drugs and toxins introduced into my body.	582 (78.6)	143 (19.3)	15 (2.0)
(K 3)The kidneys release hormones into blood to regulate blood pressure, produce red blood cells, and promote strong bones.	287 (38.8)	444 (60.0)	9 (1.2)
(K 4) CKD is a serious illness.	623 (84.2)	98 (13.2)	19 (2.6)
(K 5) CKD is an irreversible illness.	374 (50.5)	353 (47.7)	13 (1.8)
(K 7) Becoming an old person will decrease the function of my kidneys.	493 (66.6)	228 (30.8)	19 (2.6)
(K 8) Having increased blood pressure make me more likely to get CKD.	467 (63.1)	262 (35.4)	11 (1.5)
(K 9) Having diabetes mellitus make me more likely to get CKD.	551 (74.5)	169 (22.8)	20 (2.7)
(K 11) Having a family member with CKD will increase my chances of getting CKD.	257 (34.7)	475 (64.2)	8 (1.1)
(K 12) Having high lipid in my blood will increase my chances of getting CKD.	432 (58.4)	298 (40.3)	10 (1.4)
(K 13) Being a smoker increase my chances of getting CKD.	470 (63.5)	258 (34.9)	12 (1.6)
(K 14) Becoming an obese person (fatty) will increase my chances of getting CKD.	486 (65.7)	238 (32.2)	16 (2.2)
(K 15) Having untreated anemia will increase my chances of getting CKD.	412 (55.7)	314 (42.4)	14 (1.9)
(K 17) Undergoing certain procedures such as cardiac catheterization and CT scan that require injection of dye increases my chances of getting CKD.	318 (43.0)	405 (54.7)	17 (2.3)
(K 18) Having kidney stones and recurrent urinary tract infection increases my chances of getting CKD.	595 (80.4)	128 (17.3)	17 (2.3)
(K 19) Doing routine checkup of lab tests such as creatinine and serum urea nitrogen will decrease my chances of getting CKD.	535 (72.3)	194 (26.2)	11 (1.5)
(K 21) Having CKD gives trouble in concentrating.	354 (47.8)	376 (50.8)	10 (1.4)
(K 23) Having CKD gives me sleeping trouble.	445 (60.1)	285 (38.5)	10 (1.4)
(K 24) Having CKD gives me muscle cramps at night	348 (47.0)	379 (51.2)	13 (1.8)
(K 25) Having CKD gives me swollen feet and ankles and Puffiness around the eyes in the morning.	550 (74.3)	176 (23.8)	14 (1.9)
(K 26) Having CKD gives me dry and itchy skin.	351 (47.4)	375 (50.7)	14 (1.9)
(K 27) CKD gives me more often urination.	360 (48.6)	368 (49.7)	12 (1.6)
(K 28) There are five stages for CKD, and every stage need management plan.	255 (34.5)	470 (63.5)	15 (2.0)
(K 29) People in the final stage of CKD need dialysis as a life-long treatment.	323 (43.6)	401 (54.2)	16 (2.2)

Note: K, knowledge; CKD, chronic kidney disease.

Table 2. Factor loadings* for the attitudes and practices subscale using oblimin rotation.

Items within the attitude subscale	Factor I^a	Factor II^b	Factor I^c	Factor II^d
I believe that
I will be shocked if I get kidney disease.		0.40
I will talk with my friends about kidney disease.		0.72
I will talk with my family about kidney disease.		0.79
I will go to a health care provider if I have signs and symptoms of kidney disease.		0.48
Kidney disease is an expensive to diagnose and treat
Maintaining good health is extremely important.	0.73
I should search for new information to improve my health.	0.80
I feel it is important to carry out activities which will improve my health.	0.81
I want to discover my health problems in the early stages.	0.72
I want to discover my health problems in the early stages.
I feel I will get kidney problem in the future.
Doctors and nurses should have given me more information about kidney disease.	0.50
Kidney disease is from Allah (God) and nothing I can do about it.
One has an authority over his body and can prevent the occurrence of CKD.
Preventing kidney disease needs money and efforts.
Items within the practice subscale
I eat well balanced meals.			0.69
I exercise regularly such as walking and jogging.			0.65
I have regular checkups even when I'm not sick.			0.62
I keep my weight within normal range.			0.67
I not smoke.
I not drink alcohol.
I take only the medication with prescription				0.80
I follow my medications regimen.				0.81
I follow my food restrictions, such as low salt diet and diabetic diet.			0.56
I recognize abnormal changes related to CKD.			0.55
I seek medical help if I notice signs of CKD.				0.44
I get family help and support if I get CKD.

Note: *Factor loadings of 0.40 or more are presented.

^aFactor I within the attitudes subscale is actions/applications.

^bFactor II within the attitudes subscale is seeking help/assistance.

^cFactor I within the practices subscale is lifestyle.

^dFactor II within the practices subscale is compliance.

CKD, chronic kidney disease.

Table 3. Correlations between subscales within the chronic kidney disease (CKD) screening index.

CKD screening index	Knowledge	Attitudes factor I	Attitudes factor II	Practices factor I	Practices factor II
Knowledge	1.00*
Attitudes
Factor I	0.21*	1.00*
Factor II	0.21*	0.38*	1.00*
Practices
Factor I	0.28*	0.22*	0.12*	1.00*
Factor II	0.19*	0.28*	0.19*	0.33*	1.00*

Note: *All correlations are < 0.001.

Table 4. Convergent validity of the CKD screening index using “depression” and “anxiety” variables.

^aCKD screening	Depression			Anxiety
index	Mean (SD)	t Value	p Value	Mean (SD)	t Value	p Value
Knowledge		2.36	0.02		0.72	ns
Yes	38.22 (5.2)			38.4 (5.2)
No	39.2 (5.1)			38.7 (5.1)
Attitudes
Factor I		2.99	0.003		2.8	0.006
Yes	21.95 (2.8)			22.0 (2.7)
No	22.5 (2.3)			22.5 (2.5)
Factor II		2.4	0.02		1.4	ns
Yes	12.3 (2.1)			12.4 (2.1)
No	12.7 (2.1)			12.6 (2.1)
Practice
Factor I		4.06	<.0001		3.4	0.001
Yes	14.5 (3.9)			14.6 (3.9)
No	15.8 (3.6)			15.6 (3.7)
Factor II		3.3	0.001		2.3	0.02
yes	10.4 (1.7)			10.4 (1.7)
no	10.8 (1.6)			10.7 (1.6)

Note: ^aCKD screening index refers to chronic kidney disease screening index for knowledge, attitudes, and practices scale.

Table 5. Discriminant validity of CKD screening index using the “height” variable.

^aCKD screening index	Adjusted R^2	F value	Standardized coefficient (β)	p Value
Knowledge	0.001	0.95	−0.04	ns
Attitudes
Factor I	0.001	0.53	0.03	ns
Attitudes
Factor II	0.001	0.21	−0.02	ns
Practice
Factor I	0.007	5.6	0.09	0.02
Practice
Factor II	0.004	3.5	−0.07	ns

Note: ^aCKD screening index refers to chronic kidney disease screening index for knowledge, attitudes, and practices scale.