CD, or not CD, that is the question: a digital interobserver agreement study in coeliac disease

OBJECTIVE

Coeliac disease (CD) diagnosis generally depends on histological examination of duodenal biopsies. We present the first study analysing the concordance in examination of duodenal biopsies using digitised whole-slide images (WSIs). We further investigate whether the inclusion of immunoglobulin A tissue transglutaminase (IgA tTG) and haemoglobin (Hb) data improves the interobserver agreement of diagnosis.

DESIGN

We undertook a large study of the concordance in histological examination of duodenal biopsies using digitised WSIs in an entirely virtual reporting setting. Our study was organised in two phases: in phase 1, 13 pathologists independently classified 100 duodenal biopsies (40 normal; 40 CD; 20 indeterminate enteropathy) in the absence of any clinical or laboratory data. In phase 2, the same pathologists examined the (re-anonymised) WSIs with the inclusion of IgA tTG and Hb data.

RESULTS

We found the mean probability of two observers agreeing in the absence of additional data to be 0.73 (±0.08) with a corresponding Cohen's kappa of 0.59 (±0.11). We further showed that the inclusion of additional data increased the concordance to 0.80 (±0.06) with a Cohen's kappa coefficient of 0.67 (±0.09).

CONCLUSION

We showed that the addition of serological data significantly improves the quality of CD diagnosis. However, the limited interobserver agreement in CD diagnosis using digitised WSIs, even after the inclusion of IgA tTG and Hb data, indicates the importance of interpreting duodenal biopsy in the appropriate clinical context. It further highlights the unmet need for an objective means of reproducible duodenal biopsy diagnosis, such as the automated analysis of WSIs using artificial intelligence.

Association of attrition with mortality: findings from 11 waves over three decades of the Whitehall II study

BACKGROUND

Attrition, the loss of participants as a study progresses, is a considerable challenge in longitudinal studies. This study examined whether two forms of attrition, 'withdrawal' (formal discontinued participation) and 'non-response' (non-response among participants continuing in the study), have different associations with mortality and whether these associations differed across time in a multi-wave longitudinal study.

METHODS

Participants were 10 012 civil servants who participated at the baseline of the Whitehall II cohort study with 11 data waves over an average follow-up of 28 years. We performed competing-risks analyses to estimate sub-distribution HRs and 95% CIs, and likelihood ratio tests to examine whether hazards differed between the two forms of attrition. We then applied linear regression to examine any trend of hazards against time.

RESULTS

Attrition rate at data collections ranged between 13% and 34%. There were 495 deaths recorded from cardiovascular disease and 1367 deaths from other causes. Study participants lost due to attrition had 1.55 (95% CI 1.26 to 1.89) and 1.56 (1.39 to 1.76) times higher hazard of cardiovascular and non-cardiovascular mortality than responders, respectively. Hazards for withdrawal and non-response did not differ for either cardiovascular (p value =0.28) or non-cardiovascular mortality (p value =0.38). There was no linear trend in hazards over the 11 waves (cardiovascular mortality p value =0.11, non-cardiovascular mortality p value =0.61).

CONCLUSION

Attrition can be a problem in longitudinal studies resulting in selection bias. Researchers should examine the possibility of selection bias and consider applying statistical approaches that minimise this bias.

Emergency general surgery 'Hot Clinics' reduce admission rates and duration of inpatient stay

OBJECTIVE

To determine the impact of a 'Hot Clinic' (HC) on emergency general surgery patient flow-through.

DESIGN

Prospective service evaluation study.

SETTING

HC is a four-bedded area coordinated by a specialist nurse. The HC consultant sees emergency patients referred from the emergency department, general practitioners or those in preceding 24 h considered suitable for interim discharge while awaiting investigations and HC reassessment.

PATIENTS

All patients with acute abdominal pain were evaluated in three 4 week groups: before (group 1), 1 month (group 2) and 6 months after the HC was introduced (group 3). Interhospital transfers, intrahospital ward referrals and trauma patients were excluded.

INTERVENTION

Introduction of consultant-led surgical HC every weekday afternoon.

MAIN OUTCOME MEASURES

Proportion of patients admitted under general surgeons, length of inpatient stay and the proportion of patients referred again within 3 months were investigated.

RESULTS

1409 patients were referred, of which 1061 met the inclusion criteria: 307 in group 1, 326 in group 2 and 428 in group 3. There was no difference in gender distribution (p=0.759). Inpatient admissions were significantly reduced (85.0% vs 78.2% vs 54.4%; p<0.001) and the inpatient duration of stay was significantly shorter after HC introduction (median (IQR) (95% CI) 63.8 (29.0-111.6) (51.8 to 72.8) hours vs 48.8 (21.7-101.2) (42.0 to 55.6) hours vs 47.7 (20.9-92.7) (42.8 to 56.9) hours; p=0.011).

CONCLUSIONS

Emergency general surgery HCs are associated with significant reductions in admission rates and inpatient bed occupancy. This service redesign has the potential to dramatically relieve pressure on acute surgical services.

Conversion of colonoscopy to flexible sigmoidoscopy: an unintended consequence of quality measurement in endoscopy

OBJECTIVE

To quantify the proportion of requests for colonoscopy that are performed as flexible sigmoidoscopy and documented reasons for this in ordinary UK hospital practice. To determine the effect these requests have on colonoscopy completion rate if they are included in the denominator of the calculated rate by individual endoscopist.

DESIGN

Retrospective study of 22 months flexible sigmoidoscopy practice at a major UK teaching hospital. All flexible sigmoidoscopies performed had their associated request form examined.

SETTING

UK NHS University Hospital.

PATIENTS

All patients receiving outpatient flexible sigmoidoscopy from January 2013 to October 2014 with no exclusions.

INTERVENTION

Conversion of colonoscopy to flexible sigmoidoscopy.

MAIN OUTCOME MEASURES

Conversion of colonoscopy to flexible sigmoidoscopy, reason for conversion and adjusted colonoscopy completion rate.

RESULTS

71 of the 3526 flexible sigmoidoscopies performed (2.0%), representing 71 of 5905 colonoscopy requests (1.2%). Conversion reason was noted only in 26 (37%) of converted cases. Adjustment of colonoscopy completion rate to include conversions pushed four of our unit's 22 endoscopists below the UK national 90% standard.

CONCLUSIONS

Conversion to flexible sigmoidoscopy occurs in 1.2% of patients originally booked for colonoscopy. The reason for this conversion is often unqualified and may be inappropriate. Conversion can affect the colonoscopy completion rate, and therefore, should be included in endoscopists' overall performance statistics.

Hospital autopsy: Endangered or extinct?

Aim

To determine the hospital autopsy rate for the UK in 2013.

Methods

A study of data from a ‘Freedom of Information’ request to all (n=186) acute NHS Trusts within England (n=160), NHS Boards in Scotland (n=14) and Wales (n=7) and Social Care Trusts in Northern Ireland (n=5). Hospital autopsy rates were calculated from the number of hospital autopsies performed in 2013 as a percentage of total inpatient deaths in the Trust that year.

Results

The UK response rate was 99% (n=184), yielding a mean autopsy rate of 0.69%. The mean rates were 0.51% (England), 2.13% (Scotland), 0.65% (Wales) and 0.46% (Northern Ireland). 23% (n=38) of all included respondents had a rate of 0% and 86% (n=143) a rate less than 1%.

Conclusions

The decline in hospital autopsy has continued relentlessly and, for better or for worse, the practice is on the verge of extinction in the UK. The study highlights to health professionals and policy makers the magnitude of this decline. Further research should investigate the impact of this on patient safety, clinical audit, public health and medical education.