Table 2.
GRADE table reporting evidence certainty for HbA1c, TIR, TAR, TBR and PROM outcomes summarized from this umbrella review of systematic reviews evaluating the effectiveness of CGM from 2011 to 2024
| CONTINUOUS GLUCOSE MONITORING IN THE MANAGEMENT OF TYPE 2 DIABETES | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Population | Patients with Type 2 Diabetes in a Community Setting | |||||||||||
| Intervention | Continuous Glucose Monitoring | |||||||||||
| Comparator | Self-Monitoring of Blood Glucose | |||||||||||
| Certainty assessment | № of patients | Certainty | Key Message | |||||||||
| № of studies | Study design | Risk of bias | Inconsistency | Indirectness | Imprecision | Other considerations | CGM | SMBG |
Absolute (95% CI) |
|||
| pre-post HbA1c (%) change (follow-up: mean 5.08 months) | ||||||||||||
| 28 | randomized trials | serious [a] | not serious | not serious | not serious | none | 1434 | 1261 |
MD 0.42% lower (0.60 lower to 0.24 lower) |
⨁⨁⨁◯ Moderate |
HbA1c reduction was significantly greater amongst type 2 diabetes patients using CGM over SMBG/UC | |
| pre-post TIR (% day) change (follow-up: mean 5.26 months) | ||||||||||||
| 14 | randomized trials | serious [a] | not serious | not serious | not serious | none | 813 | 639 |
MD 6.00% higher (3.13 higher to 8.88 higher) |
⨁⨁⨁◯ Moderate |
TIR increase was significantly greater amongst type 2 diabetes patients using CGM over SMBG | |
| pre-post TAR (% day) change (follow-up: mean 4.62 months) | ||||||||||||
| 11 | randomized trials | serious [a] | not serious | not serious | serious | none | 653 | 460 |
MD 4.33% lower (8.37 lower to 0.28 lower) |
⨁⨁◯◯ Low |
TAR decrease was significantly greater amongst type 2 diabetes patients using CGM over SMBG | |
| pre-post TBR (% day) change (follow-up: mean 4.65 months) | ||||||||||||
| 14 | randomized trials | serious [a] | not serious | not serious | serious | none | 723 | 531 |
MD 0.33% lower (0.75 lower to 0.09 higher) |
⨁◯◯◯ Very low |
No difference in TBR changes betweem T2DM patients using CGM or SMBG/UC | |
| pre-post PROMs change [Adherence] (follow-up: mean 4 months) | ||||||||||||
| 1 | randomized trials | serious [a] | very serious [b] | serious [c] | serious [d] | none | 51 | 48 |
SMD 0.06 SD higher (0.33 lower to 0.46 higher) |
⨁◯◯◯ Very low |
No significant difference in treatment adherence change between CGM or SMBG/UC | |
| pre-post PROMs change [Distress] (follow-up: mean 6.43 months) | ||||||||||||
| 7 | randomized trials | serious [a] | very serious [b] | serious [c] | serious [d] | none | 511 | 427 |
SMD 0.66 SD higher (0.79 lower to 2.11 higher) |
⨁◯◯◯ Very low |
No significant difference in diabetes-related distress change between CGM or SMBG/UC | |
| pre-post PROMs change [Empowerment] (follow-up: mean 7.67 months) | ||||||||||||
| 3 | randomized trials | serious [a] | very serious [b] | serious [c] | serious [d] | none | 246 | 239 |
SMD 0.10 SD higher (0.24 lower to 0.45 higher) |
⨁◯◯◯ Very low |
No significant difference in patient empowerment change between CGM or SMBG/UC | |
| pre-post PROMs change [Patient Education] (follow-up: mean 5 months) | ||||||||||||
| 1 | randomized trials | serious [a] | very serious [b] | serious [c] | serious [d] | none | 20 | 10 |
SMD 0.26 SD higher (0.46 lower to 0.97 higher) |
⨁◯◯◯ Very low |
No significant difference in patient education change between CGM or SMBG/UC | |
| pre-post PROMs change [Quality-of-Life] (follow-up: mean 6.90 months) | ||||||||||||
| 5 | randomized trials | serious [a] | very serious [b] | serious [c] | serious [d] | none | 339 | 328 |
SMD 0.43 SD higher (0.14 lower to 0.99 higher) |
⨁◯◯◯ Very low |
No significant difference in quality-of-life change between CGM or SMBG/UC | |
| pre-post PROMs change [Satisfaction] (follow-up: mean 6.13 months) | ||||||||||||
| 8 | randomized trials | serious [a] | very serious [b] | serious [c] | serious [d] | none | 479 | 385 |
SMD 1.32 SD higher (0.65 lower to 3.29 higher) |
⨁◯◯◯ Very low |
No significant difference in treatment satisfaction change between CGM or SMBG/UC | |
| pre-post PROMs change [Self-Management] (follow-up: mean 6.17 months) | ||||||||||||
| 6 | randomized trials | serious [a] | very serious [b] | serious [c] | serious [d] | none | 290 | 288 |
SMD 0.68 SD higher (0.37 lower to 1.73 higher) |
⨁◯◯◯ Very low |
No significant difference in diabetes self-management change between CGM or SMBG/UC | |
CGM continuous glucose monitoring, CI confidence interval, MD Mean difference, PROMs Patient-reported outcome measure, SMBG/UC Self-monitoring of blood glucose or usual care, SD Standard deviation, SMD Standardized mean difference
Explanations
aPrimary studies poorly documented, or did not carry out, proper allocation concealment, and some studies had incomplete outcome reporting
bPrimary studies assessing quality-of-life used different quality-of-life questionnaires, which led to inconsistencies in data collection and outcome measurement, even within domains. This is especially so given the content and objectives of the questionnaires deployed were significantly different (e.g. comparing the PAID and DDS), which constitutes as heterogenous exposure to experience recall and outcome measurement amongst participants
cSome primary studies used questionnaires that studied not quality-of-life, but related constructs such as diabetes-related distress
dWithin-study variance was significant, and extensive subgroup analysis was unable to identify sources of heterogeneity across studies, leading to unexplained imprecision of results