Association between chronic kidney disease and the most common corneal ectasia disease (keratoconus): a nationwide cohort study

Table 2 Risk of chronic kidney disease in the keratoconus group and control group

Characteristics	Keratoconus				Controls				IRR (95 % CI)	p-value
	N	CKD	PY	Rate^a	N	CKD	PY	Rate^a
All	4609	48	25,491	18.83	27,654	215	154,786	13.89	1.36 (0.99 − 1.86)	0.06
Age (years)
12 − 19	1271	3	7058	4.25	7563	9	43,593	2.06	2.06 (0.56 − 7.60)	0.28
20 − 29	1884	10	10,742	9.31	11,377	34	64,806	5.25	1.77 (0.88 − 3.59)	0.11
30 − 39	898	7	4717	14.84	5340	24	28,102	8.54	1.74 (0.75 − 4.03)	0.20
≥ 40	556	28	2974	94.15	3374	148	18,284	80.95	1.16 (0.78 − 1.74)	0.46
Gender
Male	2508	29	14,050	20.64	14,804	90	83,605	10.76	1.92 (1.26 − 2.91)	0.002
Female	2101	19	11,440	16.61	12,850	125	71,180	17.56	0.95 (0.58 − 1.53)	0.82
Comorbidity
Hypertension	148	15	778	192.80	868	101	4385	230.33	0.84 (0.49 − 1.44)	0.52
Hyperlipidaemia	71	6	323	185.76	473	41	2260	181.42	1.03 (0.44 − 2.41)	0.95
Diabetes mellitus	63	9	322	279.50	338	51	1618	315.20	0.89 (0.44 − 1.80)	0.74

Note: The Poisson regression analysis was performed to calculate the incidence rate ratio
Abbreviations: CI confidence interval, CKD chronic kidney disease, IRR incidence rate ratio, PY person-years
^aRate: per 10,000 person-years

ISSN: 1471-2369