The Epidemiology of Late-Onset Inflammatory Bowel Disease
Bibliographic record
Abstract
Introduction: Inflammatory bowel disease (IBD) is a condition more commonly diagnosed in a younger population. There is evolving evidence that both Crohn's disease (CD) and ulcerative colitis (UC) are increasingly being diagnosed in older patients. Despite this, there has been little discussion on the comparative epidemiology of these two populations. Methods: Patients were selected at random from a list of those billed for diagnosis codes attributed to IBD. Of our initial list of 1006 patients, we excluded 345 patients who were inappropriately coded as having IBD. We then excluded 14 patients who did not have a known age of diagnosis leaving a final list of 648 patients. We separated our list into three cohorts: those diagnosed with IBD before the age of 45, but who are currently younger than 45 (Group 1); those diagnosed before the age of 45, but who are currently older than 45 (Group 2); and those diagnosed after the age of 45 (Group 3). Chi-squared tests were used for statistical analysis. Results: Of the 648 patients, 293 were in Group 1, 177 in Group 2, and 178 in Group 3. The average age of diagnosis for the three groups was 31.3, 31.1, and 56.5 years old respectively. Across the groups there was no statistical difference in gender and percent of patients reporting having a family history of IBD. There was a significant difference for what type of IBD was diagnosed across the three groups. In Group 1 63% of patients were diagnosed with CD, in Group 2 57% were diagnosed with CD, and in Group 3 44% were diagnosed with CD (p < 0.05). For those patients diagnosed with CD there was a trend towards a significant difference in the Montreal Classification across the three groups (p=0.06. For those with UC there was no significant difference in the extent of disease among the three groups. There was a significant difference among the groups for the frequency of patients requiring surgery (Group 1 36%, Group 2 44%, and Group 3 22%; p < 0.05). Finally, there was also a significant difference in the percent of patients with a history of smoking across the three groups (Group 1 29.6%, Group 2 41.8%, and Group 3 53.4% (p < 0.05). Conclusion: While there are similarities among patients who are diagnosed with IBD before and after the age of 45, there are some significant differences as well. These differences may provide an opportunity to better understand how the pathogenesis of IBD changes as our patients get older.Figure 1
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".