Table 3.

Univariate associations between eGFR change and factors at entry into that CKD stage

	Patient characteristic	N	Estimate*	Lower 95% CI	Upper 95% CI	P
Stage 2 (eGFR<90)	Male, n(%)	121	2.49	−2.50	7.49	0.3
	Age at PH dx (per 10 years)	121	−1.19	−2.90	0.52	0.2
	Difference b/t Symptom Onset and PH dx (per year)	106	−0.11	−0.34	0.12	0.3
	Age at 1st entry into CKD stage (per decade)	121	−2.29	−3.93	−0.65	0.01
	eGFR at 1st entry into CKD stage (per 10 mL/min/1.73 m2)	121	1.22	−0.30	2.75	0.1
	Nephrocalcinosis, n(%)	121	3.44	−1.94	8.83	0.2
	Plasma oxalate† (per 1 μmol/L)	28	0.39	−0.55	1.34	0.4
	BSA adjusted urine oxalate† (per 0.1 mmol/1.73 m2/24 h)	80	−0.14	−0.35	0.07	0.2
Stage 3a (eGFR<60)	Male, n(%)	72	8.83	−0.85	18.51	0.08
	Age at PH dx (per 10 years)	72	−1.20	−4.51	2.10	0.5
	Difference b/t Symptom Onset and PH dx (years)	66	−0.08	−0.55	0.40	0.8
	Age at 1st entry into CKD stage (per decade)	72	−2.60	−5.40	0.19	0.07
	eGFR at 1st entry into CKD stage (per 10 mL/min/1.73 m2)	72	4.12	−1.13	9.38	0.1
	Nephrocalcinosis, n(%)	72	5.17	−4.85	15.20	0.3
	Plasma oxalate† (per 1 μmol/L)	20	0.98	−0.31	2.27	0.2
	BSA adjusted urine oxalate†(per 0.1 mmol/1.73 m2/24 h)	47	−0.16	−0.48	0.16	0.3
Stage 3b (eGFR<45)	Male, n(%)	41	5.55	−9.60	20.70	0.6
	Age at PH dx (per 10 years)	41	−0.40	−5.26	4.46	0.9
	Difference b/t Symptom Onset and PH dx (years)	36	0.15	−0.50	0.79	0.7
	Age at 1st entry into CKD stage (per decade)	41	−1.44	−5.43	2.56	0.5
	eGFR at 1st entry into CKD stage (per 10 mL/min/1.73 m2)	41	−1.12	−11.64	9.40	0.8
	Nephrocalcinosis, n(%)	41	7.13	−8.49	22.75	0.4
	Plasma oxalate† (per 1 μmol/L)	18	−0.37	−1.20	0.45	0.4
	BSA adjusted urine oxalate† (per 0.1 mmol/1.73 m2/24 h)	29	−0.50	−0.96	−0.04	0.04
Stage 4 (eGFR<30)	Male, n(%)	14	−6.75	−29.20	15.70	0.6
	Age at PH dx (per 10 years)	14	3.19	−4.03	10.43	0.4
	Difference b/t Symptom Onset and PH dx (years)	13	0.64	−0.34	1.63	0.2
	Age at 1st entry into CKD stage (per decade)	14	1.40	−4.49	7.30	0.7
	eGFR at 1st entry into CKD stage (per 10 mL/min/1.73 m2)	14	−6.11	−32.72	20.50	0.7
	Nephrocalcinosis, n(%)	14	−17.50	−36.96	1.95	0.1
	Plasma oxalate† (per 1 μmol/L)	8	−0.62	−1.54	0.30	0.2
	BSA adjusted urine oxalate† (per 0.1 mmol/1.73 m2/24 h)	11	−1.15	−2.24	−0.05	0.07

Models are fit separately for different CKD stages.

^*Estimate: Change in annual absolute rate of change of eGFR (ml/min/1.73m2/year) per 1 unit increase in patient characteristic

^†Lab values at baseline were defined as occurring between 1 year prior to and up to 1 week after entry into CKD stage

P-values in bold denote statistical significance at the 0.05 alpha level.

N=number of patients.

Results were calculated using linear regression.