TABLE I.

Characteristics of Administrative Datasets and Registries Used for the Study of Pediatric Cancer

	Nationwide Inpatient Sample (NIS)	Kids Inpatient Database (KID)	Pediatric Health Information System (PHIS)	Surveillance, Epidemiology, and End Results Database (SEER)	National Cancer Data Base (NCDB)
Description	Publically-available nationally-representative all-payer inpatient care database	Publically-available nationally-representative all-payer inpatient care database for children	Privately administered database from >40 children’s hospitals	Publically-available representative population-based registry of patients with cancer	Private cancer registry of patients at hospitals in Commission on Cancer
Data Source	State public and private data organizations	State public and private data organizations	Hospital encounters, including admissions, ambulatory medical and/or short-stay, ED visits	Public and private data organizations, cancer and hospital registries	Hospital cancer registries
Sample Data	Patient demographics	Patient demographics	Patient demographics	Patient demographics	Patient demographics
	Primary and secondary diagnoses, procedures	Primary and secondary diagnoses, procedures	Primary and secondary diagnoses, procedures	Disease incidence	Tumor characteristics
	Hospital characteristics	Discharge status	Date-stamped billing data	Tumor characteristics	Hospital characteristics
	Expected payment source	Hospital characteristics	Payer information	First-course treatment	Payer information
	Total charges	Expected payment source		Survival and vital status	First-course treatment
	Discharge status	Total charges			Survival
	Length of stay	Length of stay
	Severity and comorbidity measures	Severity and comorbidity measures
Limitations	Lacks clinical data, cannot track patients across time or settings	Lacks clinical data, limited tracking across time or settings	Coding errors, lack of clinical detail, limited classification of complications, limited tracking across time or settings	Some populations overrepresented, frequency of tumor characteristics and survival limited to the racial/ethnic groups for which population denominators available	Not population-based, excludes hospitals not in the Commission on Cancer