General effect on high-risk persons when general practitioners are trained in intensive treatment of type 2 diabetes

Figures & data

Figure 1.  The ADDITION study design at the general practice level. Note: Number of practice refers to the population with IFG or IGT. Eight practices in the standard group and two in the intervention group dropped out of the study between screening and follow-up visits.

Figure 2.  Attendance at the follow-up visits of individuals with IFG or IGT in the ADDITION study, Denmark. Note: Fasting and two-hour blood glucose were measured at all follow-up visits. The three-year visit (or at study end for those more recently screened) was extended to include anthropometric measurements, blood samples, and a questionnaire with focus on changes in lifestyle since screening. The GP stopped: individuals attending GPs who after randomization stopped participation in the ADDITION study or were unable to do OGTT.

Table I.  Progression rates and baseline characteristics of individuals with IFG or IGT in the standard and intervention groups.

	IFG			IGT
	Standard	Intervention	p^1	Standard	Intervention	p^1
n	248	359		397	506
Person-years; median (interquartile range)	2.3 (81.4–2.9)	2.6 (1.1–3.0)	0.401	2.1 (0.6–2.9)	2.1 (0.8–2.9)	0.927
Progression rate, %/py (95% CI)	12.6 (9.4–15.7)	11.4 (8.9–13.8)		18.0 (14.7–21.2)	16.3 (13.6–19.0)
Age, years; mean±SD	59.8±6.7	60.0±6.1	0.654	61.2±6.7	61.3±6.6	0.846
BMI, kg/m^2; mean±SD	29.1±4.8	29.1±4.6	0.932	29.8±5.1	29.5±5.0	0.402
Systolic BP, mmHg; mean±SD	141±19	139±18	0.188	142±18.1	142±18.5	0.806
Total cholesterol, mmol/l; mean±SD	5.7±1.0	5.7±1.0	0.940	5.9±1.1	5.8±1.1	0.540
HDL, mmol/l; mean±SD	1.6±0.4	1.6±0.4	0.240	1.5±0.5	1.5±0.4	0.556
LDL, mmol/l; mean±SD	3.4±0.8	3.5±0.9	0.868	3.6±1.0	3.6±0.9	0.821
Triglyceride, mmol/l; mean (CV)^2	1.2 (0.5)	1.2 (0.5)	0.568	1.5 (0.5)	1.4 (0.5)	0.072
Women; % (n)	43.2 (107)	42.6 (153)	0.897	59.7 (237)	52.8 (267)	0.037
Known hypertension; % (n)	48.9 (115)	40.7 (138)	0.051	53.3 (204)	52.7 (251)	0.727
Low physical activity; % (n)	74.0 (176)	77.4 (267)	0.340	80.7 (314)	83.0 (405)	0.385
Daily smoker; % (n)	27.4 (68)	26.3 (93)	0.754	20.6 (80)	27.5 (137)	0.016

Notes: ¹Student's t-test (continuous variables) or chi-squared test (proportions) between standard and intervention groups. ²Geometric mean (coefficient of variation). Numbers may differ because of missing data in known hypertension (5.7%), low physical activity (3.3%) and daily smoker (1.4%).

Table II.  Change in risk-factor level in individuals with IFG or IGT: Absolute intra-individual change in the standard and intervention groups, difference in rate of change per observation time, and difference in change after one year.

Changes in risk factors	Standard care group mean (95% CI)	Intervention group mean (95% CI)	Difference in rate of change per observation time, between randomization groups^1	Difference in change after one year, between randomization groups^1 (fixed effect)	Between practice variation in change after one year (difference in change between practices)^2 (random effect)
n	445	557
Weight, kg	−0.35 (−0.79, 0.08)	−0.50 (−0.93, −0.06)	0.47 (−0.99, 1.94)	−0.50 (−1.88, 0.87)	1.21
Waist, cm	0.29 (−0.37, 0.96)	0.75 (0.11, 1.39)	0.17 (−1.99, 2.33)	−0.08 (−1.96, 1.80)	2.07
Systolic BP, mmHg	−4.4 (−6.2, −2.6)	−2.7 (−4.1, −1.3)	−0.8 (−5.4, 3.7)	1.8 (−3.1, 6.7)	2.31
Total Cholesterol, mmol/l	−0.19 (−0.29, −0.10)	−0.16 (−0.25, −0.08)	−0.08 (−0.36, 0.20)	0.06 (−0.25, 0.38)	0.17
HDL, mmol/l	0.05 (0.02, 0.07)	0.05 (0.02, 0.07)	0.03 (−0.04, 0.11)	−0.02 (−0.09, 0.05)	0.03
LDL, mmol/l)	−0.22 (−0.30, −0.14)	−0.22 (−0.30, −0.14)	−0.09 (−0.32, 0.15)	0.04 (−0.22, 0.31)	0.06
Triglyceride, mmol/l	−0.04 (−0.11, 0.02)	0.03 (−0.03, 0.10)	−0.04 (−0.22, 0.15)	0.07 (−0.11, 0.25)	0.02

Notes: Differences were analysed in a mixed model controlling for the initial value of the measurement, and with random effect of general practices as well as a random slope per general practice. ¹Mean (95% CI), ²median (95% CI).

Table III.  Proportions of persons who reported change in habits from screening to follow-up in the standard and intervention groups for individuals with IFG or IGT.

	Standard	Intervention	p^1
New BP medication; % (n)	18.1 (70)	18.9 (88)	0.980
New cholesterol medication; % (n)	13.5 (51)	16.0 (76)	0.300
My GP influenced me; % (n)	22.7 (101)	27.8 (155)	0.063
More leisure activity; % (n)	28.0 (116)	26.2 (138)	0.556
Less smoking; % (n)	8.9 (32)	10.9 (51)	0.331
Less quantity of food; % (n)	30.3 (128)	28.4 (153)	0.522
More vegetables; % (n)	44.8 (191)	44.3 (242)	0.873
More fruit; % (n)	42.2 (179)	41.2 (225)	0.752
Less sugar; % (n)	51.7 (219)	51.5 (276)	0.961
Less fat; % (n)	60.0 (255)	60.7 (329)	0.825
Less meat; % (n)	18.3 (78)	17.5 (96)	0.762
More fish; % (n)	27.9 (116)	30.9 (167)	0.315
Less alcohol; % (n)	17.7 (74)	18.8 (98)	0.673

Notes: ¹Chi-squared test between standard and intervention groups. Numbers may differ because of missing data: new BP medication (16.4%), new cholesterol medication (15.0%), more leisure time activity (6%), less smoking (17%), less quantity of food (4%), more vegetables (3%), more fruit (3%), less sugar (4%), less fat (3%), less meat (3%), more fish (5%), less alcohol (6%).