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

BACKGROUND: 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.

METHODS: 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.

RESULTS: 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.

CONCLUSION: 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.