Cohort studyindependent cross-checkfull text checked★ key study I-INS-111 in-depth review
Why young people with type 1 diabetes die in Scotland
Time trends in deaths before age 50 years in people with type 1 diabetes: a nationwide analysis from Scotland 2004-2017.
Overview
O'Reilly JE et al.. Diabetologia 2020 · PMID 32451572 · DOI 10.1007/s00125-020-05173-w
Ketoacidosis or diabetic coma caused about one in five deaths before age 50, and four in five of these deaths happened outside hospital.
Does the study support the specific claim? No · Methodological quality: high
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Analyse trends and causes of early death in T1D.
- How was the study done?
National register linkage.
- How many people, animals or samples were studied?
27,935 people, 1138 deaths.
- What was actually found?
DKA/coma 22% of deaths; mostly out of hospital.
- How large was the observed effect?
SMR 3-4.
- What do the results mean in everyday life?
Ketoacidosis remains a leading killer, especially when not treated in hospital.
- What are the study's limitations?
Combines DKA and hypoglycaemic coma.
- What does it say about Elawady's specific claim?
Contradicts 'DKA does not kill anyone'.
- Do the results apply to Germany and Europe?
UK data, directly applicable.
- What can explicitly not be concluded from this study?
Cannot separate DKA from hypoglycaemia deaths exactly.
Scientific in-depth review
1. Full reference
- Authors
- O'Reilly JE et al.
- Journal
- Diabetologia
- Year
- 2020
- Identifier
- PMID 32451572 DOI 10.1007/s00125-020-05173-w
- Verification
- verified – PubMed efetch 2026-10-26; Crossref 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- full text
- Conflicts of interest and funding
Diabetes UK (17/0005627) (full text).
2. Research question
Has mortality before 50 in T1D improved, and what are the causes?
3. Study design and population
- Study design
- Cohort study – Nationwide register-linked cohort (Scottish register + death registrations)
- Population
People with T1D aged 1-49 in Scotland
- Country
Scotland (UK)
- Period
2004-2017
- Sample size
27,935 people; 251,143 person-years; 1138 deaths
- Inclusion and exclusion criteria
T1D, age <50 and >=1 year
4. Methods and endpoints
- Exposure / intervention
T1D; calendar time
- Comparator
General population (SMR)
- Endpoints
All-cause and cause-specific death
- Statistical methods
Indirect standardisation; Poisson regression
5. Actual results
- Results
SMR about 3.1-3.6 (men) and 4.1-4.2 (women). Diabetic ketoacidosis or coma (DKAoC) accounted for 22% of deaths and its rate did not decline (IRR 0.975, 0.94-1.011); 79.3% of DKAoC deaths occurred out of hospital. Circulatory diseases 27% of deaths. Note (full text): ICD-10 coma codes do not separate ketoacidotic from hypoglycaemic coma, so DKAoC combines both.
- Absolute risks
1138 deaths in 251,143 person-years (about 4.5 per 1000 person-years)
- Authors' conclusion
Relative mortality below 50 has not improved; there is scope to prevent premature circulatory and DKA/coma deaths.
6. Strengths
- Complete national data
- Cause-specific analysis
- Full text read
7. Weaknesses
- DKA and hypoglycaemic coma combined
- Single country
- Death certificate coding
8. Risk of bias
- Orienting tool
- ROBINS-E
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- low
- Rationale
Descriptive register analysis; misclassification of cause of death possible.
9. Assessment of the statistical interpretation
Descriptive; the 22% DKAoC share is an upper bound for DKA alone because hypoglycaemic coma is included.
10. Relevance to the specific claim
In a high-income country with free insulin, ketoacidosis/coma still causes about one in five deaths before age 50, mostly outside hospital (i.e., untreated or late).
11. Independent contrary findings
12. Transferability to Germany and Europe
Directly applicable; same biology and clinical standards in Europe.
13. Overall methodological judgement
Strong evidence that DKA kills, particularly when it occurs outside hospital.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | low |
| Precision of results | high |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |