Incidence Rate of Advanced Chronic Kidney Disease Among Privately Insured Adults with Neurodevelopmental Disabilities

Figures & data

Table 1 Baseline Descriptive Characteristics of Adults With and Without Neurodevelopmental Disabilities (NDDs)

	With NDDs (n=33,561)	Without NDDs (n=6,533,687)
	% (n)	% (n)
NDD characteristics
ID only	40.1 (13,466)
CP only	21.7 (7291)
ASD only	27.5 (9212)
Multiple NDDs	10.7 (3592)
Demographic characteristics
Age, mean (SD)	44.1 (20.5)	52.8 (18.9)
Sex
Women	44.1 (14,812)	54.5 (3,562,830)
Men	55.9 (18,749)	45.5 (2,970,857)
Race
White	64.4 (21,626)	64.2 (4,194,405)
Black	9.9 (3333)	7.8 (510,358)
Hispanic	8.1 (2733)	9.5 (621,366)
Asian	3.2 (1064)	4.3 (277,725)
Unknown/missing	14.3 (4805)	14.2 (929,833)
US region
West	23.8 (7996)	25.0 (1,634,488)
Midwest	26.4 (8842)	25.8 (1,686,053)
South	36.4 (12,219)	37.8 (2,468,408)
Northeast	13.4 (4504)	11.4 (744,738)
Chronic disease comorbidities
Hypertension	28.1 (9420)	31.1 (2,029,184)
Diabetes	14.4 (4832)	13.1 (855,747)
Ischemic heart disease	5.3 (1783)	6.4 (418,310)
Heart failure	3.4 (1148)	2.3 (147,606)
Cerebrovascular disease	3.6 (1221)	2.7 (179,188)

Abbreviations: SD, standard deviation; ID, intellectual disabilities; CP, cerebral palsy; ASD, autism spectrum disorders.

Table 2 Incidence Rate of Advanced Chronic Kidney Disease (CKD) Among Adults With and Without Neurodevelopmental Disabilities (NDDs)

	Advanced CKD Cases	Person-Years	Crude Incidence Rate	Incidence Rate Ratio (IRR)
	N	Years	N per 1000/Years (95% CI)	IRR (95% CI)
Without NDDs	108,015	1,7309,025	6.24 (6.20, 6.28)	Reference
With NDDs	812	98,222	8.27 (7.70, 8.84)	1.32 (1.24, 1.42)
ID only	426	39,394	10.81 (9.79, 11.84)	1.73 (1.58, 1.91)
CP only	241	21,137	11.40 (9.96, 12.84)	1.83 (1.61, 2.07)
ASD only	89	26,917	3.31 (2.62, 3.99)	0.53 (0.43, 0.65)
Multiple NDDs*	56	10,774	5.20 (3.84,6.56)	0.83 (0.64, 1.08)

Notes: *Multiple NDDs were grouped together due to insufficient sample size (N≤10) to obtain reliable point estimates and confidence intervals. Multiple NDD groups include: ID+CP; ID+ASD; CP+ASD; or ID+CP+ASD. Two separate models were constructed with the adults without NDDs as the reference: the entire sample with NDDs; and the NDD subgroups (e.g., ID only). Reference indicates that the group was set as the reference to derive the effect estimates for the other groups.

Abbreviations: IRR, incidence rate ratio; CI, confidence interval; ID, intellectual disabilities; CP, cerebral palsy; ASD, autism spectrum disorders.

Table 3 Risk of Advanced Chronic Kidney Disease (CKD) Among Adults with Neurodevelopmental Disabilities (NDDs) Compared to Adults Without NDDs

	Model 1	Model 2	Model 3
	HR (95% CI)	HR (95% CI)	HR (95% CI)
Without NDDs	Reference	Reference	Reference
With NDDs	2.19 (2.04, 2.34)	2.01 (1.87, 2.15)	1.84 (1.72, 1.97)
ID only	2.31 (2.10, 2.54)	2.05 (1.86, 2.25)	1.88 (1.71, 2.07)
CP only	2.04 (1.79, 2.31)	1.91 (1.68, 2.17)	1.72 (1.52, 1.95)
ASD only	1.80 (1.46, 2.21)	1.77 (1.44, 2.18)	1.68 (1.37, 2.07)
Multiple NDDs*	2.93 (2.26, 3.81)	2.71 (2.09, 3.53)	2.65 (2.04, 3.45)

Notes: *Multiple NDDs were grouped together due to insufficient sample size to obtain reliable point estimates and confidence intervals. Multiple NDD groups include: ID+CP; ID+ASD; CP+ASD; or ID+CP+ASD. Two separate models were constructed with the adults without NDDs as the reference: the entire sample with NDDs; and the NDD subgroups (e.g., ID only). Reference indicates that the group was set as the reference to derive the effect estimates for the other groups.

Abbreviations: HR, hazard ratio; CI, confidence interval; ID, intellectual disabilities; CP, cerebral palsy; ASD, autism spectrum disorders; Model 1, age, sex, and US region; Model 2, age, sex, US region, and baseline hypertension and diabetes; Model 3, age, sex, US region, and baseline hypertension, diabetes, ischemic heart disease, heart failure, and cerebrovascular disease.

Table 4 Incidence Rate and Hazard Ratio (HR) of Advanced Chronic Kidney Disease (CKD) Among Adults With and Without Neurodevelopmental Disabilities (NDDs) Stratified by Age and Sex

	Advanced CKD Cases	Crude Incidence Rate	Incidence Rate Ratio (IRR)	Model 1	Model 2	Model 3
	N	N per 1000/Years (95% CI)	IRR (95% CI)	HR (95% CI)	HR (95% CI)	HR (95% CI)
Age-stratified analysis
18–39 years
Without NDDs	1725	0.41 (0.39, 0.43)	Reference	Reference	Reference	Reference
With NDDs	74	1.68 (1.30, 2.07)	4.14 (3.28, 5.22)	4.99 (3.95, 6.31)	3.83 (3.03, 4.84)	3.74 (2.96, 4.74)
40–64 Years
Without NDDs	17,848	2.53 (2.49, 2.57)	Reference	Reference	Reference	Reference
With NDDs	273	7.62 (6.71, 8.52)	3.01 (2.67, 3.39)	3.00 (2.66, 3.38)	2.32 (2.06, 2.61)	2.09 (1.85, 2.36)
≥65 years
Without NDDs	88,442	14.71 (14.61, 14.80)	Reference	Reference	Reference	Reference
With NDDs	465	25.21 (22.92, 27.50)	1.71 (1.56, 1.88)	1.74 (1.59, 1.91)	1.65 (1.51, 1.81)	1.51 (1.38, 1.65)
Sex-stratified analysis
Women
Without NDDs	53,940	5.69 (5.64, 5.74)	Reference	Reference	Reference	Reference
With NDDs	359	8.30 (7.44, 9.16)	1.46 (1.31, 1.62)	2.09 (1.88, 2.31)	1.87 (1.68, 2.07)	1.70 (1.53, 1.88)
Men
Without NDDs	54,075	6.90 (6.85, 6.96)	Reference	Reference	Reference	Reference
With NDDs	453	8.24 (7.48, 9.00)	1.19 (1.09, 1.31)	2.27 (2.07, 2.49)	2.13 (1.94, 2.33)	1.97 (1.79, 2.16)

Note: Reference indicates that the group was set as the reference to derive the effect estimates for the other groups.

Abbreviations: IRR, incidence rate ratio; CI, confidence interval; Model 1, age (as continuous), sex (except for sex-stratified analyses), and US region; Model 2, model 1 variables and baseline hypertension and diabetes; Model 3, model 2 variables and baseline ischemic heart disease, heart failure, and cerebrovascular disease.

Table 5 Incidence Rate of Advanced Chronic Kidney Disease (CKD) Among Adults With and Without Neurodevelopmental Disabilities (NDDs) with Complete Data on Race

	Advanced CKD Cases	Person-Years	Crude Incidence Rate	Incidence Rate Ratio (IRR)
	N	Years	N per 1000/Years (95% CI)	IRR (95% CI)
Without NDDs	92,416	14,839,117	6.23 (6.19, 6.27)	Reference
With NDDs	691	84,115	8.21 (7.60, 8.83)	1.32 (1.22, 1.42)
ID only	360	33,564	10.73 (9.62, 11.83)	1.72 (1.55, 1.91)
CP only	202	18,066	11.18 (9.64, 12.72)	1.80 (1.56, 2.06)
ASD only	79	23,147	3.41 (2.66, 4.17)	0.55 (0.44, 0.68)
Multiple NDDs*	50	9338	5.35 (3.87, 6.84)	0.86 (0.65, 1.13)

Notes: *Multiple NDDs were grouped together due to insufficient sample size to obtain reliable point estimates and confidence intervals. Multiple NDD groups include: ID+CP; ID+ASD; CP+ASD; or ID+CP+ASD. Two separate models were constructed with the adults without NDDs as the reference: the entire sample with NDDs; and the NDD subgroups (e.g., ID only). Reference indicates that the group was set as the reference to derive the effect estimates for the other groups.

Abbreviations: IRR, incidence rate ratio; CI, confidence interval; ID, intellectual disabilities; CP, cerebral palsy; ASD, autism spectrum disorders.

Table 6 Risk of Advanced Chronic Kidney Disease (CKD) Among Adults with Neurodevelopmental Disabilities (NDDs) Compared to Adults Without NDDs with Complete Data on Race

	Model 1	Model 1 + Race	Model 2	Model 2 + Race	Model 3	Model 3 + Race
	HR (95% CI)	HR (95% CI)	HR (95% CI)	HR (95% CI)	HR (95% CI)	HR (95% CI)
Without NDDs	Reference	Reference	Reference	Reference	Reference	Reference
With NDDs	2.19 (2.04, 2.36)	2.14 (1.98, 2.30)	2.02 (1.88, 2.18)	1.98 (1.84, 2.14)	1.86 (1.73, 2.00)	1.83 (1.69, 1.97)
ID only	2.29 (2.07, 2.54)	2.20 (1.99, 2.44)	2.05 (1.85, 2.27)	1.99 (1.80, 2.21)	1.88 (1.70, 2.09)	1.84 (1.66, 2.04)
CP only	2.01 (1.75, 2.31)	1.98 (1.73, 2.28)	1.90 (1.66, 2.18)	1.87 (1.63, 2.15)	1.71 (1.49, 1.96)	1.68 (1.47, 1.93)
ASD only	1.92 (1.54, 2.40)	1.93 (1.55, 2.40)	1.90 (1.52, 2.37)	1.89 (1.52, 2.36)	1.80 (1.45, 2.25)	1.80 (1.44, 2.24)
Multiple NDDs*	3.05 (2.31, 4.02)	2.96 (2.24, 3.90)	2.83 (2.14, 3.73)	2.77 (2.10, 3.66)	2.79 (2.12, 3.69)	2.75 (2.09, 3.63)

Notes: *Multiple NDDs were grouped together due to insufficient sample size to obtain reliable point estimates and confidence intervals. Multiple NDD groups include: ID+CP; ID+ASD; CP+ASD; or ID+CP+ASD. Reference indicates that the group was set as the reference to derive the effect estimates for the other groups.

Abbreviations: HR, hazard ratio; CI, confidence interval; ID, intellectual disabilities; CP, cerebral palsy; ASD, autism spectrum disorders; Model 1, age, sex, and US region. Model 2, age, sex, US region, and baseline hypertension and diabetes; Model 3, age, sex, US region, and baseline hypertension, diabetes, ischemic heart disease, heart failure, and cerebrovascular disease.