identifying and managing pre-diabetes: a systematic review of screening and intervention studies

IDENTIFYING AND MANAGING PRE-DIABETES: A SYSTEMATIC REVIEW OF

SCREENING AND INTERVENTION STUDIES

Dr Eleanor Barry, Dr Samatha Roberts, Dr Shanti Vijayaraghavan, Dr Jason Oke and Professor Trisha Greenhalgh

Project Aims

• Estimate and map at risk population

• Systematic Review• Identification & Interventions • Engagement• Cost-effectiveness and affordability

• Pilot Intervention

• Evaluate intervention

Newham

• Poverty• Unemployment• Overcrowding• Ethnic makeup • Diabetes and GDM

Systematic Review

Embase/Medline search

Abstract extraction

and full paper review

Meta-analysis

Three Systematic

Reviews

• 2853 abstracts• 49 test papers• 49 intervention trials

Test Accuracy

Studies using HbA1c as index test and OGTT as reference standard.

Sensitivity 0.49 (CI 0.40-0.58)Specificity 0.79 (CI 0.73- 0.84AUROC 0.71Partial AUROC 0.59

Test Accuracy

Studies using FPG as index test and IGT as reference standard.

Sensitivity 0.25 (CI 0.19 to 0.32)Specificity 0.94 (CI 0.04 to 0.08)AUROC 0.72Partial AUROC 0.422

Test PrevalenceAnalysis of Pre-Diabetes Prevalence by Diagnostic Test using WHO and IEC criteria in UK population.

Data extracted from Mostafa et al doi:10.1016/j.diabres.2010.06.008

HbA1c IGT

IFG

Of those who had an abnormal test:-Isolated IFG- 4.7%Isolated IGT- 24.4%Isolated HbA1c- 47.8%IFG+IGT -2.9%IFG +HbA1c -4.1%IGT +HbA1c -12.2%IGT+IFG+Hba1c -3.9%

N= 8696, Prevalence 27.2%

Test selection

Why is this important?

• Each test reflects a different underlying process.

• Different rates of progression.

• Behave differently.

• Commissioning implications.

• Trials still use OGTT/IGT as gold standard in patient selection.

Lifestyle InterventionsForrest Plot 1: Relative risk reduction at the end of the trial

Lifestyle Interventions

Forrest Plot 2: Relative risk reduction at follow up post intervention

Real World Applicability

Pre-Diabetes population

71% Eligible RCT

33% Randomised

27% Completed trial

Qualitative review

Extracted from Greenhalgh et al DOI: 10.1186/s12916-015-0360-1

Newham Strategies

38,940 people QDS

>20%NHS DPP and LES

Population based approach

Gestational Diabetes

Conclusions• Who is most at risk?• HbA1c correctly identifies half of people at high risk of

DM• HbA1c abnormal in twice as many people

• Individualised interventions• Intervention at least 2-3 years in length and intensive at

onset• Surrogate outcomes do not equal diabetes incidence

reduction• What about everyone else?

• Disconnect between literature

• Explore underlying complexity of condition.

Questions?

Eleanor BarryNIHR In-Practice Fellow

Eleanor.barry@phc.ox.ac.uk