Examining the quality of name code record linkage: what is the impact on death and cancer risk estimates? A validation study.
OBJECTIVE
To examine the validity and impact of record linkage using name code compared to full name records.


METHODS
A registry of 45,419 opioid substitution clients (1985-2007) was linked with national population-based death and cancer registries using registrant's name, date of birth, sex, state, postcode and date of death. Records were linked using full name and then using the first two letters of the given and surname (2×2 name code). Sensitivity and specificity were computed and regression analysis used to identify factors related to linkage accuracy. Standardised mortality ratios (SMR) and standardised cancer incidence ratios (SIR) were estimated.


RESULTS
The sensitivity and specificity of name code compared to full name linkage were 65.31% and 99.91% for death records and 76.81% and 99.89% for cancer records. Registrants' age and sex and accuracy of the registries were associated with risk of false linkages. Death and cancer risks (SMR 6.98, 95%CI 6.77-7.19; SIR 1.16, 95%CI 1.08-1.24) were significantly under-estimated using name code linkage (SMR 4.39, 95%CI 4.23-4.56; SIR 0.92, 95%CI 0.85-0.99).


CONCLUSIONS
Record linkage using 2×2 name code has low sensitivity but high specificity, resulting in conservative estimates of death and cancer risk. This may translate to meaningful differences in outcomes.
Adult Cancer Program, Prince of Wales Clinical School, University of New South Wales.
Alexander
A
Swart
Nicola S
NS
Meagher
Marina T
MT
van Leeuwen
Kun
K
Zhao
Andrew
A
Grulich
Limin
L
Mao
Deborah Anne
DA
Randall
Louisa
L
Degenhardt
Lucy
L
Burns
Dianne
D
O'Connell
Janaki
J
Amin
Claire M
CM
Vajdic
D000328:Adult; D000368:Aged; D001315:Australia; D003644:Death Certificates; D005260:Female; D006801:Humans; D015994:Incidence; D038801:International Classification of Diseases; D008297:Male; D008498:Medical Record Linkage / Q000379:methods / Q000592:standards*; D008875:Middle Aged; D009313:National Health Programs / Q000706:statistics & numerical data*; D009369:Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D011785:Quality Assurance, Health Care; D012042:Registries; D012306:Risk; D012680:Sensitivity and Specificity
accuracy; cancer; mortality; name code; record linkage; risk; sensitivity; specificity; validity