Table 2. Average hospitalization rates, relative hospitalization rates and absolute excess rates in CCS and matched reference persons.

	CCSa		Matched reference personsb
	Hospitalizations	Hospitalization rate per 1000 py at risk	Hospitalizations	Hospitalization rate per 1000 py at risk	RHR	95%CI	AER per 1000 py at risk
All individuals	1736	172.4	13765	79.1	2.2	1.9–2.5	93.3
Gender
Male	693	129.5	4876	53.1	2.4	2.0–3.0	76.4
Female	1043	221.0	8889	108.2	2.0	1.7–2.4	112.8
Primary cancer diagnosis
Leukemia/lymphoma	530	120.0	5536	72.8	1.6	1.4–2.0	46.7
CNS	184	264.3	939	77.2	3.4	2.7–4.4	187.1
Sarcomas	369	185.9	3224	90.8	2.0	1.5–2.8	95.1
Other solid tumors	563	210.1	3631	79.3	2.6	2.0–3.5	130.8
Other and unspecified cancers	90	329.8	435	98.0	3.4	2.0–5.5	231.8
Recurrences of primary cancer before five-year survival
None	1436	159.8	11995	78.6	2.0	1.8–2.4	81.2
Any	300	277.2	1770	82.9	3.3	2.5–4.5	194.3
Cancer treatmentc, d
No chemotherapy or radiotherapy	180	219.5	1255	88.6	2.5	1.5–4.1	130.9
Chemotherapy	614	119.0	6020	67.8	1.8	1.4–2.2	51.2
Radiotherapy	240	344.6	1188	102.0	3.4	2.2–5.0	242.7
Chemotherapy and radiotherapy	701	206.9	5298	89.4	2.3	2.0–2.7	117.6

^a Time at risk in CCS was censored at the date of five-year survival in case of ongoing primary cancer recurrence treatment or at the incidence date of first primary cancer recurrence after the date of five-year survival.

^b Up to 20 reference persons were sampled per survivor and categorized into cancer diagnosis and treatment groups according to the corresponding CCS

^c Cancer treatment groups were mutually exclusive, i.e. persons could contribute to one cell only. Treatment categories were irrespective of surgical treatment.

^d We took all cancer treatment that was given before the date of five-year survival into account.

Abbreviations: CCS: childhood cancer survivors; py: person years; RHR: relative hospitalization rate; CI: confidence interval; AER: absolute excess rate.