End-digit preference and related factors in blood pressure recording

Objective To investigate the status of end-digit preference ( EDP ) in blood pressure ( BP ) recording in different hospitals and departments. Methods In December 2011 , the BP recordings of 21medical units , including five tertiary hospitals ( TH ), nine county secondary hospitals ( CH ) and seven primary community health centers ( HC ), were investigated. The BP data of hospitals were collected from the medical recording in ward , and those of the HC were the health records of the last two months. A total of 3560BP records from 1793males and 1767 females were collected. The percentage of odd number end-digital ( nonstandard recording ) was calculated and the percentage of zero end-digital ( 0-EDP ) was calculated when the records ended with even numbers or zero. Results Compared with that of TH , the percentages of nonstandard records [ systolic blood pressure ( SBP ): 21.7% , 16.4% vs 11.8% ; diastolic blood pressure ( DBP ): 22.1% , 14.8% vs 12.8% , all P0.05 ] and 0-EDP ( SBP : 82.2% , 74.9% vs 71.8% ; DBP : 80.5% , 71.6% vs 72.5% , all P0.05 ) of CH and HC were higher.In the comparison between different departments , the 0-EDP of SBP in general surgery department was higher than that in internal medicine department ( TH : 74.5% vs 70.2% ; CH : 80.5% vs 70.7% ; all P0.05 ) . Logistic regression analysis showed that the increase of age , higher BP level , lower hospital grade and surgery department were the precipitating factors for 0-EDP. Conclusion There is high proportion of nonstandard BP recording in medical services of hospitals and primary community health centers , and the zero end-digit preference is very common.