OBJECTIVES: In poorly-controlled patients with NITDM the Structured Testing Protocol (STeP) study has shown improved HbA1c outcomes of a structured testing group (STG) versus enhanced usual care that included unstructured SMBG (active control group (ACG)) at overall cost neutrality over one year. This work analyzes HbA1c and testing frequencies in previously non active testers. METHODS: The underlying assumption of this exploratory analysis is that not active testers (STG: n=80; ACG: n=61) - the study participants who did not test in the week before the study – do in general not test systematically and might be particularly responsive to structured SMBG. For both groups HbA1c  and the testing frequencies were calculated based on meter download data. RESULTS: At baseline both groups did not differ in any characteristic. Baseline HbA1c was 9.1 (Standard deviation1.2)%. In not active testers ITT analysis revealed a 0.59% (95%-CI: 0.07 to 1.11; p<0.03) larger HbA1c difference in STG than in ACG (STG: -1.71% (-2.06, -1.37); ACG: -1.12% (-1.51, -0.73)). STG performed significantly fewer tests/day than ACG (mean = 0.72 vs. 0.96, p=0.04). This equates to a -25% difference in annual test strip consumption between the STG (263 tests/year) and ACG (350 tests/year). While a relatively high test frequency was imposed by the study protocol in the beginning of the STeP study, in last study quarter average testing was 0.63 per day in STG and 0.79 per day in ACG (n.s.) (equivalent to 230 vs. 288 per year). CONCLUSIONS: Structured SMBG in not active testers was associated with higher reductions in HbA1c compared to standard SMBG use and compared to the overall STeP population. The use of structured SMBG may be especially cost-effective in terms of HbA1c reduction per test strips used in patients with poorly controlled NITDM who do not show a history of consistent SMBG use.