Longitudinal outcomes
chronic illness, non-shared HbA1c goalHbA1c, diabetes
CHRONIC ILLNESS, DIABETES
After two years (T4), 235 (43%) achieved the HbA1c goal, and 312 (57%) missed the goal. As with baseline HbA1c, patients with a shared HbA1c goal also show slightly lower HbA1c at T4 (see Table 
Follow-up characteristics (T4) including bivariate comparisons of the samples shared vs. non-shared HbA1c goalHbA1c glycated haemoglobin; SD standard deviation; SDM-Q-9 shared decision making (9 items scored 0–5, total score is the sum 0–45, more SDM with higher score); PACIC patient assessment of chronic illness care (11 items scored 1–5, score is the mean 1–5, better care with higher score); PAID problem areas in diabetes (20 items scored 0–4, total score is the sum multiplied by 1.25 = 0-100, more distress with higher score); EQ-5D-3 L quality of life (5 items with 3 levels, total score is the weighted EQ-5D index from low negative values to 1.0, better QoL with higher score)Multivariable analysis (Table 
Multivariable influences on outcome „HbA1c goal missed”*Generalized Estimating Equation with cluster effect “GP practice”, binomial, logit link*higher outcome = higher risk of missing the goal (measured HbA1c at T4 is > 0.5 above goal); T0 baseline, T4 two years after baselineSensitivity analyses are shown in Additional file 2 tables. The direction and pattern of results is robust: Shared vs. non-shared HbA1c use shows no association with goal achievement, whereas living with a partner and taking no insulin are associated with better goal achievement. With T2 criterion (1 year after baseline), higher age is also slightly associated with better goal achievement.Concerning the overall diabetes outcome (composite score), shared vs. non-shared use of an HbA1c goal also shows no association (Table 
Multivariable influences on outcome „T4 composite score [HbA1c/distress/QoL]”*Generalized Estimating Equation with cluster effect “GP practice”, normal, identity link*composite of HbA1c/PAID/reversed EQ-5D, higher composite score = worse outcome T0 baseline, T4 two years after baseline