12 months before and after switching from premix to glargine (A), mean change in HbA
after switch (B), mean use of bolus insulin before and after switch (C) and mean total daily insulin dose before and after switch (D) (unadjusted data). The last measurement for premix is at -3 months (indicated by vertical dotted line). During period -12 m to -3 m patients are taking premix only. During the 3 month switch time point (0 months) patients may be prescribed premix and glargine. During period +3 m to +12 m patients are only prescribed glargine (± prandial boluses). Linearly interpolated data were used to graphically depict the change in each parameter. Linearly interpolated data affords a clearer graphical interpretation but may bias estimates of variance; as such error bars (95% confidence intervals for the means) are not reported. Total daily insulin dose was calculated according to the number of units prescribed divided by the number of days covered by the prescription.