Table 3. Subgroup analysis
Co-efficient95% CI
LowerUpper
2015–2016 QP in bottom 80% of prescribers-0.116-0.125-0.106
Effect of 2015–2016 QP in top 20% of prescribers-0.200-0.210-0.187
Top 20% of prescribers0.3090.3020.316
Months since QP0.0130.0130.014
SeasonWinterRefRefRef
Spring-0.046-0.049-0.044
Summer-0.148-0.151-0.145
Autumn-0.124-0.126-0.121
 Comorbidities prevalence per 100 patientsRespiratory diseases0.0130.0110.015
Diabetes (<3.93%)0.0970.0890.106
Diabetes (≥3.93% to ≤7.59%)0.0150.0120.017
Diabetes (≥7.60% to ≤11.28%) before QP0.0160.0120.021
Diabetes (≥7.60% to ≤11.28%) after QP0.0070.0020.011
Diabetes (>11.28%)0.0410.0300.052
 GPHC per 10 000 patients, spline termsGPHC1 (<4.91) before QP0.0150.0130.017
GPHC1 (<4.91) after QP0.0070.0050.009
GPHC2 (≥4.91 to ≤9.80) before QP-0.007-0.009-0.005
GPHC2 (≥4.91 to ≤9.80) after QP-0.005-0.007-0.003
GPHC3 (≥9.81 to ≤14.72)0.005-0.0000.010
GPHC4 (>14.72)-0.007-0.0220.008
Benzodiazepine anxiolytics prescription0.0930.0890.097
Benzodiazepine hypnotics prescription0.1180.1150.121
  • Effects of diabetes are per 1% higher within each spline term. Effects of GPHC are per 1 higher per 10 000 patients within each spline term. GPHC = GP headcount. QP = Quality Premium.