Table 1

Data sources and variables

RegistriesVariables
Exposures
NOPHO ALL Registry*1 20Relapse of ALL
First remission
Danish Cancer Registry†25Second malignant neoplasm
Outcomes
Primary health careNational Health Insurance Service Register‡23Daytime contacts to general practice:
Daytime face-to-face contacts
Email consultations
Daytime telephone consultations
Daytime home visits
Out-of-hours contacts:
Out-of-hours face-to-face contacts
Out-of-hours telephone consultations
Out-of-hours home visits
Diagnostic procedures in general practice:
Blood test
Urine test
Streptococcus throat test
Pulmonary functions test
Electrocardiogram
Secondary health careDanish National Patient Registry§26Contacts to public and private hospitals:
Inpatient hospitalisations
Outpatient visits
Covariates
Danish Civil Registration System27Sex
Age
Vital status
Immigration
Emigration
NOPHO ALL RegistryDiagnosis of childhood ALL
Treatment protocol (ALL1992, ALL2000 or ALL2008)
Risk group (high-risk or non-high risk)
Immunophenotype (B-precursor ALL or T-ALL)

  • *NOPHO ALL Registry, Nordic Society of Paediatric Haematology and Oncology ALL Registry. The registry holds data on all children aged 1.0–14.9 years in Denmark diagnosed with ALL since 1992. From 2008 and onwards, the ALL Registry was extended to include children and adolescents aged 1.0–17.9 years.

  • †The Danish Cancer Registry holds information on all new cases of cancer in Denmark.

  • ‡The National Health Insurance Service Register holds information on all contacts to general practice in Denmark. The following contacts were excluded: preventive health examination of children, vaccinations, screening for cervical cancer and pregnancy care. For a complete list of codes, see online supplemental table S2.

  • §The Danish National Patient Registry holds information on all contacts to public and private hospitals. The following contacts were excluded: visits to the accident and emergency department.

  • ALL, acute lymphoblastic leukaemia.