TABLE 2.

Comparison of the databases

	NSQIP	NIS	SEER	NCDB
Sponsor/association	Sponsored by the American College of Surgeons	Part of the HCUP sponsored by the AHRQ	Sponsored by the Surveillance Research Program in the National Cancer Institute’s Division of Cancer Control and Population Sciences	Sponsored jointly by the American College of Surgeons and the American Cancer Society
Brief description	National, risk-adjusted, outcomes-based database that aims to measure morbidity and mortality to improve the quality of care of surgical patients	All-payer inpatient-care database, which reports estimates of inpatient utilization and outcomes; a 20% stratified sample of discharges from all HCUP-participating hospitals	Population-based cancer database; data inclusion is based on the geographic location and captures ~30% of newly diagnoses cancers	Hospital-based cancer database; data are collected from Commission on Cancer-accredited facilities in the U.S.; captures >70% of newly diagnosed cancer cases and ~30% of U.S. hospitals (>1500 of 5000)
Time period	2005–2019	1988–2018	1975–2018	1989–2017
Basic demographics	Sex, race (5 options), ethnicity (Hispanic/Latino), weight/height	Sex, race/ethnicity (5 options)	Sex, race (30 options), ethnicity (Hispanic/Latino)	Sex, race (30 options), ethnicity (Hispanic/Latino)
Age (years)	≥18	All ages	All ages	All ages
Socioeconomic, education, and insurance information	None	Expected primary payer Median household income by zip code Total hospital charges	Median household income by zip code	Primary payer Median household income by zip code Educational attainment in area of residence (estimated % in zip code without high school degree)
Comorbidities	Comorbidities Functional status ASA classification Preoperative laboratory values Estimated probability of mortality and morbidity Year of death	Comorbidities (2002–2015) All patient refined diagnosis-related groups (APR DRGs) APR DRG mortality risk classification APR DRG severity of illness classification	None	Charlson-Deyo comorbidity score
Facility Information	None	Control/ownership of hospital (e.g., government, private) Bed size of hospital Teaching status of hospital Region of the hospital (4 categories)	Urban-rural continuum of treatment facility Type of reporting source (e.g., hospital, radiation center, laboratory, outpatient office, autopsy)	Urban-rural continuum of treatment facility Facility type (Community Cancer Program, Comprehensive Community Cancer Program, Academic-Research Program, Integrated Network Cancer Program) Facility location (9 categories) Great circle distance (distance in miles between patient’s residence and reporting hospital)
Hospitalization Information	Inpatient vs outpatient Quarter of admission Days from admission to operation Days from operation to discharge Length of hospital stay Discharge destination Readmission information	Inpatient only Admission weekday/ weekend and month Elective vs non-elective admission Length of hospital stay Death during hospitalization Discharge quarter Discharge destination No. of days from admission to each procedure Transfer from or to another facility	No information regarding specific hospitalizations	Length of surgical inpatient stay Readmission to the same hospital within 30 days after surgical discharge
Surgery Information	Surgical specialty performing primary operation Anesthesia type Operative time Level of resident in operating room Elective vs emergent operation CPT codes (21 codes available per patient) RVU associated with each CPT code Surgical wound closure Wound classification Postoperative outcomes and complications Unplanned reoperation information NSQIP provides information to determine whether a procedure is uni- or bilateral, but does not indicate if a unilateral procedure is on the right or left The 21 CPT codes per patient provided in NSQIP allows researchers to indicate immediate oncoplastic breast procedures (performed at the time of lumpectomy) and immediate breast reconstruction procedures (performed at the time of mastectomy). Researchers are also able to examine delayed breast reconstruction procedures, but the previous mastectomy procedure details will not be associated with that patient encounter	No. of procedures per discharge ICD9 and ICD10 procedure codes (25 procedure codes available per patient) NIS provides information to determine whether a procedure is uni- or bilateral. As of 2015, with the transition to ICD 10 procedure codes, researchers are also able to determine if a procedure was performed on the right or left. The 25 procedure codes per patient provided in NIS allows researchers to indicate immediate oncoplastic breast procedures (performed at the time of lumpectomy) and immediate breast reconstruction procedures (performed at the time of mastectomy). Researchers are also able to examine delayed breast reconstruction procedures, but the previous mastectomy procedure details will not be associated with that patient encounter unless it occurred during the same inpatient admission (which is unlikely)	Site-specific surgery coding system (1 code per patient) Reason for no surgery of primary site, if applicable Scope of regional lymph node surgery involvement is available for certain cancers but is not available for breast cancer cases SEER provides laterality of the disease (right vs left). Site-specific surgery codes indicate whether the patient had no surgical intervention, lumpectomy, or mastectomy (with or without contralateral prophylactic mastectomy, and with or without breast reconstruction during the first course of treatment). Immediate and delayed post-lumpectomy oncoplastic procedure information is not provided. Delayed breast reconstruction information is not provided	Site-specific surgery coding system (1 code per patient) Surgical diagnostic and staging procedure information Days from diagnosis to first surgical procedure and days from diagnosis to definitive surgical procedure Surgical margins of primary site Scope of regional lymph node surgery Surgical procedure to sites other than primary site Reason for no surgery of primary site, if applicable 30- and 90-day mortality after surgery NCDB provides laterality of the disease (right vs left). Site-specific surgery codes indicate whether the patient had no surgical intervention, lumpectomy, or mastectomy (with or without contralateral prophylactic mastectomy, and with or without breast reconstruction during the first course of treatment). Immediate and delayed post-lumpectomy oncoplastic procedure information is not provided. Delayed breast reconstruction information is not provided
Diagnosis Information	Diagnosis code (ICD-9 and ICD-10 diagnosis codes); 1 code per patient Laterality of disease is not provided ICD 9/10 diagnosis codes may indicate genetic susceptibility to breast malignancy of family history or breast cancer, but specific BRCA1/2 information is not provided	Diagnosis code (ICD9 and ICD10 diagnosis codes) ; 40 codes available per patient No. of diagnoses per discharge MDC on day of discharge Laterality of disease is not provided (laterality of procedure is provided beginning in 2015). ICD 9/10 diagnosis codes may indicate genetic susceptibility to breast malignancy or family history of breast cancer, but specific BRCA1/2 information is not provided.	See oncologic data	See oncologic data
Oncologic Information	No specific oncologic information other than the diagnosis code	No specific oncologic information other than diagnosis code	Uses ICD-O-3 classification Behavior, histology, grade, tumor size Laterality of disease if applicable Method of diagnostic confirmation (e.g., histology, cytology) No. of primary tumors (in situ and/or invasive) Regional lymph nodes examined (number) and positivity of regional lymph nodes Presence of distance metastases at time of diagnosis (bone, brain, liver, lung, distant lymph nodes, or other) Combined (clinical and pathologic) TNM staging Site-specific factors for breast cancer (see Supplemental Table for additional information) ER and PR assays HER2: summary result of testing BRCA1/2 status is not provided Treatment details–surgery, systemic therapy* (and timing relative to surgery), radiation therapy (and timing relative to surgery) *Regarding systemic therapy, SEER does not differentiate between chemotherapy, endocrine therapy, and immunotherapy. Vital status of patient (overall survival) Survival (months)	Uses ICD-O-3 classification Behavior, histology, grade, tumor size Laterality of disease if applicable Method of diagnostic confirmation (e.g., histology, cytology) No. of primary tumors (in situ and/or invasive) Regional lymph nodes examined (number) and positivity of regional lymph nodes Presence of distance metastases at time of diagnosis (bone, brain, liver, lung, distant lymph nodes, or other) Separate clinical TNM staging and pathologic TNM staging Site-specific factors for breast cancer (see Supplemental Table for additional information) ER and PR) assays HER2: summary result of testing BRCA1/2 status is not provided. Location of initial diagnosis vs location of treatment Treatment details-surgery, systemic therapy (and timing relative to surgery), radiation therapy (and timing relative to surgery) Detailed information on timing, type, and dose of radiation (see Supplemental Table) Detailed information on timing and type of systemic therapy (chemotherapy, endocrine therapy, and immunotherapy) (see Supplemental Table) Palliative care treatment information Vital status of patient (overall survival) Survival (months)

^*The asterisks refer to extra information/added information

NSQIP National Surgical Quality Improvement Program, NIS Nationwide Inpatient Sample, SEER Surveillance, Epidemiology and End Results program, NCDB National Cancer Database, HCUP Healthcare Cost and Utilization Project, AHRQ Agency for Healthcare Research and Quality, ASA American Society of Anesthesiologists, APR DRG all patient refined diagnosis-related group, CPT current procedural terminology, RVU relative value unit, ICD International Classification of Diseases, MDC major diagnostic category, ER estrogen receptor, PR progesterone receptor, HER2 human epidermal growth factor receptor