Table 3

Adjusted ORs of recording zero as the last digit for both systolic and diastolic blood pressure by patient and site characteristics

EffectIndex groupReference groupCanadaUK
OR95% CIP valueOR95% CIP value
Age (years)18–3980+1.0881.063 to 1.112<0.0010.7840.773 to 0.795<0.001
40–5980+1.0120.990 to 1.0340.2940.7880.777 to 0.798<0.001
60–7980+0.9420.923 to 0.963<0.0010.7830.772 to 0.794<0.001
SexFemaleMale1.1001.089 to 1.112<0.0011.1561.148 to 1.163<0.001
BMIUnderweight (BMI<18.5)Obesity class III (BMI>40)1.3161.267 to 1.366<0.0011.0471.019 to 1.0740.001
Normal (BMI 18.5–24.9)Obesity class III1.2261.192 to 1.258<0.0010.9600.939 to 0.980<0.001
Overweight (BMI 25–29.9)Obesity class III1.1351.104 to 1.166<0.0010.9470.926 to 0.966<0.001
Obesity class I (BMI 30–34.9)Obesity class III1.0651.036 to 1.096<0.0010.9530.932 to 0.973<0.001
Obesity class II (BMI 35–39.9)Obesity class III1.0080.978 to 1.0400.6180.9670.943 to 0.9920.007
DiabetesYesNo0.9820.964 to 0.9990.0471.0251.008 to 1.0420.004
HypertensionYesNo0.8920.877 to 0.908<0.0010.7900.780 to 0.799<0.001
Hypertension medicationsYesNo0.9670.947 to 0.9860.0011.0571.047 to 1.068<0.001
Practice site sizeFirst quartile (smallest site)Fourth quartile (largest site)1.9501.908 to 1.990<0.0010.8160.809 to 0.823<0.001
Second quartileFourth quartile (largest site)1.0751.058 to 1.094<0.0010.8930.885 to 0.900<0.001
Third quartileFourth quartile (largest site)1.0871.074 to 1.100<0.0010.8910.883 to 0.899<0.001
Measurement year200620151.9101.833 to 1.990<0.0011.6471.625 to 1.668<0.001
200720151.9231.857 to 1.989<0.0011.4731.451 to 1.494<0.001
200820151.8401.790 to 1.895<0.0011.3761.357 to 1.396<0.001
200920151.8581.815 to 1.903<0.0011.3211.300 to 1.341<0.001
201020151.5821.548 to 1.617<0.0011.2571.238 to 1.275<0.001
201120151.3791.352 to 1.407<0.0011.1781.161 to 1.196<0.001
201220151.2391.216 to 1.262<0.0011.1121.094 to 1.129<0.001
201320151.0961.077 to 1.116<0.0011.0521.038 to 1.067<0.001
201420151.0371.021 to 1.052<0.0011.0161.000 to 1.0300.041
  • ORs were adjusted for patient age, sex, presence of hypertension and/or diabetes, BMI, use of hypertensive medications. ORs were also adjusted for the size of the practice panels and year of measurement.

  • BMI, body mass index (weight in kg/height in m2).