The quality of vital signs measurements in electronic medical records varies by hospital, specialty, and patient demographics
Authors: Jackson Niall , Woods Jessica , Watkinson Peter , Brent Andrew , Peto Tim EA , Walker A Sarah , Eyre David W 
Published: January 2022

Objective

To assess the frequency of digit preference in recording of vital signs in electronic healthcare records (EHRs) and associated patient and hospital factors.

Study Design and Setting

We used EHR data from Oxford University Hospitals, UK, between 01-January-2016 and 30-June-2019 and multivariable logistic regression to investigate associations between temperature readings of 36.0°C or systolic and diastolic blood pressure (SBP/DBP) readings both ending in zero and patient age, sex, ethnicity, deprivation, comorbidities, calendar time, hour of day, days into admission, hospital, day of week and speciality.

Results

In 4,305,914 records from 143,352 patients, there was an excess of temperature readings of 36.0°C (15.1%, 649,976/4,305,914), compared to an expected 4.9% from the underlying distribution. 2.2% (95,215) BP readings had a SBP and DBP both ending in zero vs. 1% expected by chance. Digit preference was more common in older and male patients, as length of stay increased, following a previous normal set of vital signs and typically more common in medical vs. surgical specialities. Differences were seen between hospitals, however, digit preference reduced over calendar time.

Conclusion

Vital signs may not always be accurately documented. Allowances and adjustments may be needed in observational analyses using these factors as outcomes or exposures.

What’s New?

Key findings

▪

Digit preference in the recording of vital signs in electronic healthcare records is common, affecting approximately 10% of temperature measurements and 1% of blood pressure recordings in a large UK teaching hospital group

▪

These findings were obtained in hospitals using a semi-automated data capture system that required manual re-entry of vital signs into a tablet computer prior to automated upload to electronic patient records

▪

Digit preference was associated with patient characteristics and was more common in older and male patients, as length of stay increased and following previously normal vital signs

▪

Digit preference varied between hospitals, but decreased over time

▪

Digit preference was generally more common in medical compared to surgical specialties

What this adds to what is known

▪

Most previous studies of data quality in electronic patient records have focused on the accuracy of coding

▪

This study focuses on the accuracy of numeric values in patient records, and also adds new data on patient and hospital factors associated with the accuracy of values in electronic patient records

Implications

▪

Clinicians and researchers need to be aware that vital signs may not always be accurately documented

▪

Appropriate allowances and adjustments for digit preference should be considered in observational analyses using these factors as outcomes or exposures.

▪

Further work is required to understand the mechanisms behind values preference on a systems, patient and clinician level