Table 3.

Non-exhaustive Summary of Variables to be Used From ICES Databases and Extracted by Health Records Review for Both the Prospective and Retrospective Studies.

ICES Database	Brief description of how we will use the database	Variables of interest
Pediatric Oncology Group of Ontario Networked Information System (POGONIS) Available from 1985 Data collected by all cancer sites	• Cancer patient identification, sex, age at cancer diagnosis date • Cohort entry date (diagnosis date/date of definitive diagnostic procedure) • Cancer treatment start/end date (first/last treatment given) • Cancer diagnosis type • Treatment type (eg, chemotherapy, radiation, SCTx with details) • Treatment site (hospital) • Death date (linked to other databases, eg, RPDB) • Previous cancer (will be supplemented with Ontario Cancer Registry linkage, not described in proposal)	• Date of Birth • Sex • Pathologically Confirmed Diagnosis • Date of Diagnosis • Radiation Type + Technique • Amount of Radiation Used • Date of Death • Treatment Start/End Date • Date of Receiving Stem Cell • Transplant • Treatment (including “watch and wait” versus palliative versus treatment) • Drug Name and doses for alkylating agents and platinums
Ontario Cancer Registry (OCR) Available from 1964 + National Ambulatory Care Reporting System (NACRS) + Cancer Care Ontario Activity Level Reporting (ALR) + Records within the New Drug Funding Plan + OHIP, DAD, SDS below	• Collectively, to supplement POGONIS with treatments (including outpatient and systemic therapies), diagnosis, death, pathologies, and consultation records for patients ≥15 years old who are not found in POGONIS (as per Kitchlu et al36,37).	• Age at Diagnosis • Date of Diagnosis • Sex • Diagnosis (and body part), treatments, locations • Relapse, second malignancy
Discharge Abstract Database (DAD) + Same Day Surgery Database (SDS) Available from 1991	• Identify hospitalizations and dates, used for comorbidities assessments, diagnoses and procedures (eg, dialysis—for AKI during cancer therapy), demographic information	• Admission/Discharge date • Birth date/Weight/Age • Dialysis, mechanical ventilation, • Radiotherapy, chemotherapy, y/n • Diagnosis/Procedure codes • Region/Education/Residence
MOMBABY database Available from 1988	• Contribute to identify admissions prior to cohort entry in infants to evaluate comorbidities • Birth weight	• Birth Date, sex • Birth weight (grams) • Diagnoses
Ontario Health Insurance Plan Claims Database (OHIP) Available from 1991	• Identify nephrology consultations through Ontario physician billings • Maintenance dialysis codes—Contribute to end stage renal disease/kidney transplant (pre-cancer CKD- defining) • Define most baseline comorbidities listed in proposal	• Diagnostics Code (includes codes for consultation, dialysis, cardiac, etc.) • OHIP fee code (as above) • Location of OHIP claim • Physician number (for consult type through link with IPDB) • Physician specialty
Registered Persons Database (RPDB) Available from 1991	• Date of last contact (and OHIP coverage end date) • Birth date • Death date (with POGONIS) • Socioeconomic status and rural variables	• Birth date • Death date • Neighborhood Income Quintile • Rurality Index • Date of last contact
Canadian Organ Replacement Registry (CORR) Available from 1981	• Past kidney transplant, dialysis • Kidney transplant, maintenance dialysis (for CKD definition, pre-cancer)	• Kidney Transplant • Death date • Hemodialysis/Peritoneal dialysis
ICES Physician’s Database (IPDB) Available from 1991	• Physician specialty for visits (eg, oncology care, AfterCare, primary care; nephrology)	• Physician specialty (first, second, etc.) • Primary care (yes/no)
Ontario Laboratory Information System (OLIS) Database Available from 2007	• Serum creatinine, cystatin C, urinary protein/albumin, vitamin D, hemoglobin, parathyroid hormone measures • Ordering center, provider, and lab destination • For prospective study: Goal is mainly to identify AKI during cancer therapy, as we have previously defined, using serum creatinine criteria of the KDIGO definition. OLIS will provide serum creatinine data to define AKI during cancer therapy for all sites except SickKids, which has not yet contributed to OLIS. For the retrospective study (need labs as far back as 2007), OLIS data available for sites in Kingston, Hamilton, London, and Ottawa from as far back as 2015, 2014, 2013 and 2016, respectively.	• Birth Date • Destination Lab • Measure type (eg, albumin, protein) • Measure value (+ ref range, units) • Ordering Facility / Provider
Variables to be collected by site staff via chart abstraction	Labs above and dates; whether inpatient or outpatient. Prospective study: Baseline and study visit medical, medication and family history characteristics; inclusion and exclusion criteria (including relevant chemotherapies received); routinely collected labs above performed closest to the study visits. At SickKids only: serum creatinine values throughout cancer therapy to define AKI and monthly serum creatinine and urine albumin/protein performed during routine care from cancer therapy end to date of first study visit. Retrospective study: Lab values described above will need to be collected by site research staff during the following time periods (years not available in OLIS provincial database): Kingston: 2007-2014 Hamilton: 2007-2013 London: 2007-2012 Ottawa: 2007-2015 SickKids: 2007-2020	• Destination Lab • Measure type (eg, albumin, protein) • Measure value (+ ref range, units) • Ordering Facility / Provider • CKD y/n, adherence y/n (from measures) • Together with other databases, determine if inpatient or outpatient lab test.

Abbreviations: POGONIS = Pediatric Oncology Group of Ontario Networked Information System; SCTx = stem cell treatment; OCR = Ontario Cancer Registry; NACRS = National Ambulatory Care Reporting System; OHIP = Ontario Health Insurance Plan; DAD = Discharge Abstract Database; SDS = Same Day Surgery Database; AKI = acute kidney injury; CKD = chronic kidney disease; IPDB = ICES Physician Database; RPBD = Registered Persons Database; OLIS = Ontario Laboratory Information System; CORR = Canadian Organ Replacement Registry; KDIGO = Kidney Disease Improving Global Outcomes; ALR = activity level reporting.