Summary of findings 5. Summary of findings: risk of intermediate hyperglycaemia (combined IFG and IGT definition) versus normoglycaemia for developing T2DM.
| Outcome: development of T2DM Prognostic factor: intermediate hyperglycaemia as measured by combined IFG and IGT | ||||
| No of studies | No of participants with intermediate hyperglycaemia | Geographic region/special population | Estimated effect (95% CI) [95% prediction interval] | Overall certainty of the evidence (GRADE)a |
| HR: 3 IRR: 4 OR: 3 |
HR: 461 IRR: 3166 OR: 498 |
Asia/Middle East |
HR: 10.20 (5.45–19.09) [N/M] IRR: 11.20 (5.59–22.43) [N/M] OR: 6.99 (3.09–15.83) [N/M] |
⊕⊕⊝⊝ Lowb |
| HR: 1 IRR: 4 OR: 6 |
HR: 221 IRR: 699 OR: 154 |
Australia/Europe/North America |
HR: 3.80 (2.30–6.28) [N/M] IRR: 13.92 (9.99–19.40) [6.71–28.85] OR: 20.95 (12.40–35.40) [4.93–89.05] |
|
| HR: 0 IRR: 0 OR: 0 |
HR: 0 IRR: 0 OR: 0 |
Latin America |
HR: NA IRR: NA OR: NA |
|
| HR: 1 IRR: 1 OR: 0 |
HR: 356 IRR: 605 OR: 0 |
American Indians/Islands |
HR: 4.06 (3.05–5.40) IRR: 5.18 (3.42–7.83) OR: NA |
|
| HR: 5 IRR: 9 OR: 9 |
HR: 1038 IRR: 4470 OR: 652 |
Overall |
HR: 6.90 (4.15–11.45) [1.06–44.95] IRR: 10.94 (7.22–16.58) [2.58–46.46] OR: 13.14 (7.41–23.30) [1.84–93.66] |
|
| CI: confidence interval; HR: hazard ratio;IFG: impaired fasting glucose; IGT: impaired glucose tolerance; IRR: incidence rate ratio; NA: not applicable; N/M: fewer than 3 studies or calculation of the 95% prediction interval did not provide a meaningful estimate; OR: odds ratio; T2DM: type 2 diabetes mellitus. | ||||
| GRADE Working Group grades of evidence High quality: further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: we are very uncertain about the estimate. | ||||
aWith phase 2 explanatory studies aiming to confirm independent associations between the prognostic factor and the outcome, GRADE starts with 'high quality' (Huguet 2013). We assumed the GRADE factor publication bias was inherent with this type of research (phase 2 design), so we did not use it as a potential downgrading factor bDowngraded by one level because of study limitations (many studies did not adequately adjust for confounders, if at all) and by one level because of imprecision (CIs were wide) and inconsistency (wide 95% prediction intervals)