Background
Research question
Methods
Model structure
Model parameters
Health state | Diagnostic test | Diagnostic criteria | Prevalence | Annual incidence of T2DM | Annual cost of care (£, 2015) | Utility (QALYs) |
---|---|---|---|---|---|---|
Normoglycaemia (NGT) | Any of fasting blood glucose, post-load glucose or glycated haemoglobin | Fasting glucose: <5.6 mmol/L Post-load glucose: <7.0 mmol/L HbA1c: <6.0 mmol/mol | £773
[Gamma distribution, SE: £102.63]
| 0.768
[Beta distribution, SE: 0.10]
| ||
Impaired fasting glucose (IFG) | Fasting blood glucose: blood glucose test after a period of fasting (typically overnight) | Fasting glucose: 5.6-6.9 mmol/L | Isolated IFG: 12.76% IFG + IGT: 1.49% IFG + HbA1c: 6.61% IFG + IGT + HbA1c: 1.06% | 3.55%
[Beta distribution, SE: 0.006]
| £869
[Gamma distribution, SE: 104.56]
| 0.759
[Beta distribution, SE: 0.11]
|
Impaired glucose tolerance (IGT) | Post-load glucose: blood glucose test 2 hours after consuming a drink containing 75 g of sugar | 2 hour post-load glucose: 7.0-11.1 mmol/L | Isolated IGT: 7.50% IGT + HbA1c: 3.31% | 4.54%
[Beta distribution, SE: 0.004]
| £946
[Gamma distribution, SE: 101.52]
| 0.746
[Beta distribution, SE: 0.10]
|
HbA1c | Glycated haemoglobin: blood test which estimates blood glucose levels over previous 2-3 months | 6.0-6.4 mmol/mol | Isolated HbA1c: 7.53% | 3.56%
[Beta distribution, SE:0.017]
| £869
[Gamma distribution, SE: 104.56]
| 0.759
[Beta distribution, SE: 0.11]
|
Type 2 Diabetes Mellitus (T2DM) | Any of fasting blood glucose, post-load glucose or glycated haemoglobin | Fasting glucose: >6.9 mmol/l 2 hour post-load glucose: >11.1 mmol/L | £1,179-£2,939 Increasing linearly from Year 1-15
[Gamma distribution, SE: 270.00]
| 0.738
[Beta distribution, SE: 0.12]
|
Clinical and epidemiological parameters
Interventions
Costs (Additional file 1: Appendix 2)
Utilities
Intervention | Annual cost of intervention (£, 2015) | Incremental utility associated with intervention (QALY) | Relative risk of developing T2DM |
---|---|---|---|
Pragmatic lifestyle programme | Yr 1: £203.44 Yr 2: £80.02 | 0.0189
[Beta distribution, SE: 0.001]
| During intervention: IFG: 0.74/IGT: 0.74/HbA1c: 0.74
[Lognormal distribution, SE: 0.11]
|
Intensive lifestyle programme | Yr 1: £1225 Yr 2: £689 Yr 3: £671 | 0.0189
[Beta distribution, SE: 0.001]
| During intervention: IFG: 0.63/IGT: 0.55/HbA1c: 0.71
[Lognormal distribution, SE: 0.10 (IFG), 0.07 (IGT), 0.10 (HbA1c)]
Up to 7 years post- intervention: IFG: 0.80/IGT: 0.80/HbA1c: 0.71
[Lognormal distribution, SE: 0.06 (IFG), 0.06 (IGT), 0.10 (HbA1c)]
|
Metformin | £124.25 | 0.0031
[Beta distribution, SE: 0.002]
| IFG: 0.82/IGT: 0.82/HbA1c: 0.62
[Lognormal distribution, SE: 0.05(IGT), 0.05 (IFG), 0.10 (HbA1c)]
|
Analyses
Sensitivity analyses
Validation
Results
Outcomes for individual participants in a prevention programme
Method of identifying participants | Intervention | Total cost (£,2015) | Total QALYs | Prevalence of T2DM after 50 years (%) | Average number of years lived with T2DM after 50 years |
---|---|---|---|---|---|
IGT | No intervention | 17,772 | 11.53 | 42% | 5.75 |
Pragmatic lifestyle programme | 17,774 | 11.59 | 41% | 5.43 | |
Intensive lifestyle programme | 18,423 | 11.76 | 33% | 3.97 | |
Metformin | 17,988 | 11.60 | 38% | 5.03 | |
IFG | No intervention | 17,429 | 12.13 | 38% | 5.34 |
Pragmatic lifestyle programme | 17,440 | 12.19 | 37% | 5.07 | |
Intensive lifestyle programme | 18,452 | 12.28 | 31% | 3.98 | |
Metformin | 17,908 | 12.20 | 35% | 4.68 | |
HbA1c | No intervention | 17,436 | 12.13 | 38% | 5.35 |
Pragmatic lifestyle programme | 17,446 | 12.19 | 37% | 5.08 | |
Intensive lifestyle programme | 18,507 | 12.27 | 31% | 4.03 | |
Metformin | 17,475 | 12.23 | 33% | 4.18 |
Method of identifying participants | No intervention | Low intensity lifestyle programme | High intensity lifestyle programme | Metformin | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Incidence T2DM | Incidence T2DM | Relative risk reduction | Incidence T2DM | Relative risk reduction | Incidence T2DM | Relative risk reduction | ||||||||
After 10 years | After 50 years | After 10 years | After 50 years | At 10 years | At 50 years | After 10 years | After 50 years | At 10 years | At 50 years | After 10 years | After 50 years | At 10 years | At 50 years | |
IGT | 23% | 42% | 22% | 41% | 7% | 3% | 14% | 33% | 39% | 21% | 20% | 38% | 16% | 9% |
IFG | 19% | 38% | 18% | 37% | 7% | 3% | 13% | 31% | 35% | 17% | 16% | 35% | 16% | 9% |
HbA1c | 19% | 38% | 18% | 37% | 7% | 3% | 13% | 31% | 35% | 17% | 13% | 33% | 35% | 14% |
Method of identifying participants | Intervention | Incremental cost effectiveness ratio (ICER)
(relative to next best intervention)
| Cost effectiveness ratio (CER)
(relative to no intervention)
| ||||||
---|---|---|---|---|---|---|---|---|---|
Incremental cost (£, 2015) | Incremental effect (QALYs) | ICER (£/QALY) | Probability ICER < £20,000/QALY | Cost vs no intervention (£, 2015) | Effect vs no intervention (QALYs) | CER (£/QALY) | Probability CER < £20,000/QALY | ||
IGT | No intervention | - | - | - | - | - | - | - | - |
Low-intensity lifestyle | 3 | 0.06 | 44 | 98.19% | 3 | 0.06 | 44.33 | 98.19% | |
Metformin | Subject to extended dominance | 367 | 0.07 | 5,224 | 75.86% | ||||
High-intensity lifestyle | 649 | 0.18 | 3,707 | 74.58% | 652 | 0.23 | 2,775 | 80.5% | |
IFG | No intervention | - | - | - | - | - | - | - | - |
Low-intensity lifestyle | 11 | 0.06 | 195 | 98.5% | 11 | 0.06 | 195 | 98.5% | |
Metformin | Subject to extended dominance | 479 | 0.07 | 6,842 | 76.28% | ||||
High-intensity lifestyle | 1,012 | 0.09 | 11,219 | 75.09% | 1,023 | 0.15 | 6,820 | 81.44% | |
HbA1c | No intervention | - | - | - | - | - | - | - | - |
Low-intensity lifestyle | 11 | 0.06 | 186 | 97.79% | 11 | 0.06 | 186 | 97.79% | |
Metformin | 28 | 0.05 | 600 | 50.40% | 39 | 0.10 | 372 | 77.89% | |
High-intensity lifestyle | 1,032 | 0.04 | 25,481 | 40.38% | 1,071 | 0.15 | 7,376 | 71.28% |
Incremental cost-effectiveness ratios (ICERs) – comparison with the next best alternative
Cost-effectiveness ratios – comparison with no intervention
Effect on diabetes prevalence
Outcomes of a nation-wide prevention programme
Method of identifying participants | Intervention | Reduction in incident cases of T2DM (number of cases) | % reduction in incident cases of T2DM | Reduction in average number of years lived with T2DM (number of years) | % reduction in average number of years lived with T2DM (%) |
---|---|---|---|---|---|
IGT | Pragmatic lifestyle programme | 2,938 | 0.3% | 0.03 | 0.5% |
Intensive lifestyle programme | 20,494 | 1.9% | 0.15 | 2.7% | |
Metformin | 9,388 | 1.9% | 0.07 | 1.3% | |
IFG | Pragmatic lifestyle programme | 11,582 | 1.1% | 0.04 | 0.7% |
Intensive lifestyle programme | 32,119 | 3.0% | 0.19 | 3.4% | |
Metformin | 20,863 | 1.9% | 0.11 | 2.0% | |
HbA1c | Pragmatic lifestyle programme | 15,856 | 1.5% | o.03 | 0.6% |
Intensive lifestyle programme | 33,027 | 3.1% | 0.15 | 2.8% | |
Metformin | 29,163 | 2.7% | 0.14 | 2.5% |