Related Experiment Video
Updated: May 8, 2026

Optimization of Breast Biopsy and Mastectomy Sample Collection Procedures for Biobanking, Personalized Medicine, and Research Applications
Published on: September 2, 2025
Assessing the Importance of Variation in Diagnostic Coding Among the Three Countries in the UK Biobank
Lei Clifton1, Wenyu Liu2, Jennifer A Collister2
1Nuffield Department of Primary Care Health Sciences University of Oxford Oxford UK.
Background:
The UK Biobank (UKB) study has linked hospital inpatient data collected from England, Scotland, and Wales, which use different clinical coding systems to record health outcomes. Scotland records up to 6 different diagnostic codes for one inpatient episode, compared with up to 20 in England and 14 in Wales. We assessed the relationship of the variations in diagnostic coding among countries on observed disease incidence rates.
Methods:
We examined the number of diagnoses coded by each country, and then compared the incidence of three diseases between countries: Parkinson's disease (PD), type 2 diabetes (T2D), and dementia. We constructed Cox models for each disease, adjusting for "country."
Results:
Compared with England, Scotland appears to have the lowest risk (hazard ratio, HR) for all three diseases: HR [95% CI] = 0.62 [0.54, 0.72] for PD, 0.49 [0.45, 0.54] for T2D, and 0.88 [0.78, 0.99] for dementia.
Conclusions:
The observed incidence of these diseases and the estimated effect of "country" in Cox models are likely influenced by the clinical coding variations among countries. Researchers need to be aware of this and account for these variations in their analyses.
More Related Videos
05:49Use of Magnetic Resonance Imaging and Biopsy Data to Guide Sampling Procedures for Prostate Cancer Biobanking
Published on: October 10, 2019
06:55Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index
Published on: January 8, 2020
Related Concept Videos
Bias in Epidemiological Studies
Variability: Analysis
The range is a simple measure of variability, indicating the difference between the highest and...
Comparing Copy Number Variations and SNPs
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Biostatistics: Overview
Discrete variables are...
Genetic Variation
Genes exist in different versions called alleles, which...
Genome-wide Association Studies-GWAS
GWAS does not require the identification of the target gene involved in...