Table 1

ITSA of monthly prescribing data on sodium-containing medications and control medications between 2012 and 2013 versus 2014 and 2015, THIN data

Baseline level (95% CI)Baseline slope (95% CI)Change in level (95% CI)P valueChange in slope (95% CI)P value
Prescribing rate
 Sodium overall69.2 (65.9 to 72.5)0.03 (−0.13 to 0.18)0.59 (−2.19 to 3.37)0.678−0.26 (−0.45 to −0.07)0.009
 Non-sodium overall (control)765.1 (728.8 to 801.3)1.58 (−0.08 to 3.24)22.3 (−8.14 to 52.7)0.1511.14 (−0.99 to 3.27)0.294
 Sodium analgesics35.1 (33.8 to 36.4)−0.11 (−0.17 to −0.05)0.59 (−0.53 to 1.71)0.303−0.03 (−0.10 to 0.05)0.510
 Sodium calcium supplements7.95 (7.48 to 8.41)0.01 (−0.01 to 0.03)0.36 (−0.01 to 0.73)0.059−0.03 (−0.06 to −0.01)0.014
 Sodium GI motility agents22.9 (21.6 to 24.2)0.10 (0.04 to 0.16)0.05 (−1.08 to 1.19)0.927−0.17 (−0.24 to −0.09)<0.001
 Sodium corticosteroids2.5 (2.3 to 2.7)0.02 (−0.30 to 0.11)−0.10 (−0.30 to 0.11)0.370−0.03 (−0.05 to −0.02)<0.001
Proportion of patients
 Sodium overall56.4 (54.2 to 58.6)0.03 (−0.08 to 0.13)0.56 (−1.29 to 2.41)0.554−0.22 (−0.35 to −0.09)<0.001
 Non-sodium overall (control)554.4 (534.9 to 573.8)1.07 (0.18 to 1.96)15.3 (−1.02 to 31.6)0.071.13 (−0.01 to 2.28)0.052
 Sodium analgesics27.5 (26.8 to 28.3)−0.09 (−0.13 to −0.06)0.32 (−0.36 to 0.99)0.36−0.01 (−0.05 to 0.04)0.716
 Sodium calcium supplements6.40 (6.15 to 6.64)0.01 (−0.01 to 0.02)0.31 (0.11 to 0.52)0.003−0.03 (−0.05 to −0.02)<0.001
 Sodium GI motility agents20.62 (19.6 to 21.7)0.09 (0.05 to 0.14)0.18 (−0.69 to 1.05)0.691−0.16 (−0.22 to −0.10)<0.001
 Sodium corticosteroids2.20 (1.99 to 2.41)0.01 (0.01 to 0.02)−0.10 (−0.28 to 0.09)0.302−0.03 (−0.04 to −0.02)<0.001
 Sodium user man39.10 (37.61 to 40.59)0.04 (−0.02 to 0.11)0.36 (−0.94 to 1.65)0.590−0.16 (−0.26 to −0.09)<0.001
 Sodium user woman73.38 (70.51 to 76.25)0.01 (−0.01 to 0.01)0.77 (−1.64 to 3.18)0.532−0.27 (−0.44 to −0.10)0.002
 Sodium user age <45 years12.96 (12.29 to 13.63)−0.03 (−0.06 to 0.00)0.23 (−0.35 to 0.81)0.439−0.03 (−0.07 to 0.01)0.113
 Sodium user age 45–54 years43.77 (42.03 to 45.51)0.04 (−0.04 to 0.11)−0.17 (−1.71 to 1.38)0.833−0.12 (−0.22 to −0.02)0.020
 Sodium user age 55–64 years81.07 (78.21 to 83.92)−0.07 (−0.19 to 0.06)−0.41 (−2.95 to 2.14)0.754−0.21 (−0.38 to −0.05)0.011
 Sodium user age 65–74 years128.34 (123.23 to 133.46)0.30 (0.07 to 0.53)−2.28 (−6.72 to 2.16)0.314−0.68 (−0.98 to −0.39)<0.001
 Sodium user age 74–84 years226.90 (219.18 to 234.62)−0.05 (−0.40 to 0.30)3.18 (−3.52 to 9.87)0.352−0.71 (−1.15 to −0.26)0.002
 Sodium user age ≥85 years304.96 (293.46 to 316.46)−0.37 (−0.88 to 0.13)9.45 (−0.78 to 19.69)0.070−0.69 (−1.35 to −0.03)0.041
  • Bold values signify p<0.05

  • ITSA, interrupted time series analysis; THIN, The Health Improvement Network.