Systematic review of the literature
| Study . | Patients . | Intervention . | Control . | Face-to-face consultations . | Study design . | Outcome . |
|---|---|---|---|---|---|---|
| Pediatric patients | ||||||
| Marrero et al., 1995 (26) | 106 type 1 diabetic pediatric patients on multiple daily insulin injections with inadequate control. | Modem transmission every 2 weeks, with clinician feedback (algorithm triggered). | No scheduled intervisit contacts or data transmission. | Every 3 months. | Parallel RCT. No report of loss to follow-up. Outcome: HbA1c at 6 and 12 months. | Telecare: Mean HbA1c (nl 6.5–8.0%) changed from 9.4% to 9.6 (6 months) and to 10.0 (12 months). Control: Changed from 9.9% to 9.7 (6 months.) and to 10.3 (12 months.). Difference: NS |
| Pregnant patients | ||||||
| Wojcicki et al., 2001 (27) | 32 pregnant type 1 diabetic patients using intensive insulin therapy and with inadequate control. | Nightly modem transmission, with daily clinician feedback. | No scheduled intervisit contacts or data transmission. | Every 3 weeks. | Parallel RCT. Two patients were excluded from analysis because of illness after randomization. Outcome: HbA1c at 6 months. | Telecare: Mean HbA1c (nl NR) changed from 7.9% to 6.8. Control: Changed from 8.1% to 6.7. Difference: NS |
| Adult patients | ||||||
| Ahring et al., 1992 (24) | 42 type 1 diabetic patients not using intensive insulin therapy and with inadequate control. | Modem transmission every week, with clinician feedback | No scheduled intervisit contacts or data transmission. | At baseline, 6 weeks, and 12 weeks. | Parallel RCT. Two patients lost to follow-up from each arm. Outcome: HbA1c at 3 months. | Telecare: Mean HbA1c (nl 4.5–9.0%) changed from 10.6% to 9.2. Control: Changed from 11.2% to 10.2. Difference: NS |
| Gómez et al., 2002 (28) | 10 type 1 diabetic patients with inadequate glycemic control. | Modem transmission every 2 weeks, with clinician feedback within the 24 h following each transmission. | No scheduled intervisit contacts or data transmission. | Every 6 months. | Crossover RCT (period duration of 6 months). No data reported on loss to follow-up. Outcome: HbA1c at 6 months. | Telecare: Median HbA1c (nl NR) changed from 8.4% to 7.9. Control: Changed from 8.1% to 8.2. Difference: NS |
| Bierdmann et al., 2002 (22,23) | 48 type 1 diabetic patients using intensive insulin therapy and with inadequate control. | Modem transmission at least every 2 weeks, with clinician feedback every 2 to 4 weeks. | Face-to-face visits at least every month. | Every 2 months. | Parallel RCT. Five patients lost to follow-up at 4 months. Outcome: HbA1c at 4 months (data at 8 months available for only 21 patients). | Telecare: Mean HbA1c (nl NR) changed from 8.3% to 6.9. Control: Changed from 8.0% to 7.0. Difference: NS |
| Chase et al., 2003 (25) | 70 type 1 diabetic patients with some receiving intensive insulin therapy and with a wide range of glycemic control. | Every 2 weeks, with clinician feedback. | No scheduled intervisit contacts or data transmission. | Every 3 months (omitting the mid-third month visit in the intervention group). | Parallel RCT. Seven patients were excluded from analysis (five from the intervention arm because of failure to transmit data and three from the control arm for failure to attend the 3-month visit). Outcome: HbA1c at 6 months. | Telecare: Mean HbA1c (nl 3.2–6.2%) changed from 9.0% to 8.6. Control: Changed from 8.9% to 8.6. Difference: NS |
| Welch et al., 2003 (29) | 52 type 1 diabetic patients with poor glycemic control. | Every 2 to 4 weeks, with clinician feedback. | No scheduled intervisit contacts or data transmission. | Every 3 months. | Parallel RCT. Of 52 patients, 18 (10 from the control arm) and 28 (16 from the control arm) were lost to follow-up at 6 and 12 months, respectively. Outcome: HbA1c at 6 and 12 months. | Telecare: Mean HbA1c changed from 8.9% to 8.6 (6 months) and to 8.5 (12 months). Control: Changed from 9.1% to 8.9 (6 months) and to 9.0 (12 months). Difference: NS at 6 and 12 months. |
| Montori et al., 2004 (present study) | 31 type 1 diabetic patients using intensive insulin therapy and with inadequate control. | Modem transmission at least every 2 weeks, with clinician feedback. | Modem transmission at least every 2 weeks, with clinician feedback on demand. | Every 3 months. | Parallel RCT. Three patients lost to follow-up (two from the intervention arm). Outcome: HbA1c at 6 months. | Telecare: Mean HbA1c (4.0–6.1%) changed from 9.1% to 7.8. Control: Changed from 8.8% to 8.2. Difference (after adjusting for baseline difference in HbA1c): P = 0.03. |
| Study . | Patients . | Intervention . | Control . | Face-to-face consultations . | Study design . | Outcome . |
|---|---|---|---|---|---|---|
| Pediatric patients | ||||||
| Marrero et al., 1995 (26) | 106 type 1 diabetic pediatric patients on multiple daily insulin injections with inadequate control. | Modem transmission every 2 weeks, with clinician feedback (algorithm triggered). | No scheduled intervisit contacts or data transmission. | Every 3 months. | Parallel RCT. No report of loss to follow-up. Outcome: HbA1c at 6 and 12 months. | Telecare: Mean HbA1c (nl 6.5–8.0%) changed from 9.4% to 9.6 (6 months) and to 10.0 (12 months). Control: Changed from 9.9% to 9.7 (6 months.) and to 10.3 (12 months.). Difference: NS |
| Pregnant patients | ||||||
| Wojcicki et al., 2001 (27) | 32 pregnant type 1 diabetic patients using intensive insulin therapy and with inadequate control. | Nightly modem transmission, with daily clinician feedback. | No scheduled intervisit contacts or data transmission. | Every 3 weeks. | Parallel RCT. Two patients were excluded from analysis because of illness after randomization. Outcome: HbA1c at 6 months. | Telecare: Mean HbA1c (nl NR) changed from 7.9% to 6.8. Control: Changed from 8.1% to 6.7. Difference: NS |
| Adult patients | ||||||
| Ahring et al., 1992 (24) | 42 type 1 diabetic patients not using intensive insulin therapy and with inadequate control. | Modem transmission every week, with clinician feedback | No scheduled intervisit contacts or data transmission. | At baseline, 6 weeks, and 12 weeks. | Parallel RCT. Two patients lost to follow-up from each arm. Outcome: HbA1c at 3 months. | Telecare: Mean HbA1c (nl 4.5–9.0%) changed from 10.6% to 9.2. Control: Changed from 11.2% to 10.2. Difference: NS |
| Gómez et al., 2002 (28) | 10 type 1 diabetic patients with inadequate glycemic control. | Modem transmission every 2 weeks, with clinician feedback within the 24 h following each transmission. | No scheduled intervisit contacts or data transmission. | Every 6 months. | Crossover RCT (period duration of 6 months). No data reported on loss to follow-up. Outcome: HbA1c at 6 months. | Telecare: Median HbA1c (nl NR) changed from 8.4% to 7.9. Control: Changed from 8.1% to 8.2. Difference: NS |
| Bierdmann et al., 2002 (22,23) | 48 type 1 diabetic patients using intensive insulin therapy and with inadequate control. | Modem transmission at least every 2 weeks, with clinician feedback every 2 to 4 weeks. | Face-to-face visits at least every month. | Every 2 months. | Parallel RCT. Five patients lost to follow-up at 4 months. Outcome: HbA1c at 4 months (data at 8 months available for only 21 patients). | Telecare: Mean HbA1c (nl NR) changed from 8.3% to 6.9. Control: Changed from 8.0% to 7.0. Difference: NS |
| Chase et al., 2003 (25) | 70 type 1 diabetic patients with some receiving intensive insulin therapy and with a wide range of glycemic control. | Every 2 weeks, with clinician feedback. | No scheduled intervisit contacts or data transmission. | Every 3 months (omitting the mid-third month visit in the intervention group). | Parallel RCT. Seven patients were excluded from analysis (five from the intervention arm because of failure to transmit data and three from the control arm for failure to attend the 3-month visit). Outcome: HbA1c at 6 months. | Telecare: Mean HbA1c (nl 3.2–6.2%) changed from 9.0% to 8.6. Control: Changed from 8.9% to 8.6. Difference: NS |
| Welch et al., 2003 (29) | 52 type 1 diabetic patients with poor glycemic control. | Every 2 to 4 weeks, with clinician feedback. | No scheduled intervisit contacts or data transmission. | Every 3 months. | Parallel RCT. Of 52 patients, 18 (10 from the control arm) and 28 (16 from the control arm) were lost to follow-up at 6 and 12 months, respectively. Outcome: HbA1c at 6 and 12 months. | Telecare: Mean HbA1c changed from 8.9% to 8.6 (6 months) and to 8.5 (12 months). Control: Changed from 9.1% to 8.9 (6 months) and to 9.0 (12 months). Difference: NS at 6 and 12 months. |
| Montori et al., 2004 (present study) | 31 type 1 diabetic patients using intensive insulin therapy and with inadequate control. | Modem transmission at least every 2 weeks, with clinician feedback. | Modem transmission at least every 2 weeks, with clinician feedback on demand. | Every 3 months. | Parallel RCT. Three patients lost to follow-up (two from the intervention arm). Outcome: HbA1c at 6 months. | Telecare: Mean HbA1c (4.0–6.1%) changed from 9.1% to 7.8. Control: Changed from 8.8% to 8.2. Difference (after adjusting for baseline difference in HbA1c): P = 0.03. |
nl, normal range; NR, not reported; RCT, randomized controlled trial.