Zero and Five End-Digit Preference and Blood Pressure Quality of Care Revisited

To determine the rate of zero and five end-digit preference (EDP) for systolic and diastolic blood pressures (SBP and DBP, respectively) and risk factors amongst a representative sample of Iranian adults in the year 2011.

Data gathered from 7997 Iranian adults aged 25-70 were extracted from the database of the sixth Survey of Surveillance of Risk Factors of Non-communicable Diseases, which surveyed a total of 11,864 individuals aged 6 to 70 years. Multilevel multiple logistic regression was used to identify the independent factors associated with zero or five EDP.

The prevalence of three serial zero or five EDP for SBP and DBP were 18.5% (95% CI: 11.3%-25.7%). SBP ≥140 mmHg (OR = 0.78; 95% CI: 0.65-0.95), DBP ≥90 mmHg (OR = 0.71; 95% CI: 0.58-0.88), and a positive family history of diabetes (OR = 0.77; 95% CI: 0.66-0.9) were found as protective factors against zero or five EDP in blood pressure recording the male gender (OR = 1.18; 95% CI: 1.04-1.35) was found to be its independent risk factor.

Sex, SBP, DBP and family history of diabetes were found to be the main independent determinants of EDP in our country which underscores the importance of assessing the many patient-related factors in the studies involving EDP as part of BP monitoring in public health care.