Patient reporting of self-measured blood pressure in logbooks showed substantial observer error compared to device memory, with under-reporting averaging 36% and precision at 76%.
Observational (n=30)
Is patient reporting of self-measured blood pressure values in a logbook reliable compared to automatically stored device readings in hypertensive patients?
There is substantial observer error, primarily under-reporting, when hypertensive patients manually record self-measured blood pressure, highlighting the need for memory-equipped devices.
For self-measurement of blood pressure to be useful, patient reporting of test results must be reliable and accurate. Until now no study directly measured the accuracy and reliability of patients' reporting of self-measured blood pressure values. Thirty hypertensive patients (69 +/- 11 years) were instructed to measure blood pressure at home over 14 days with the highly accurate Omron IC monitor and to keep a record of all readings in a patient logbook. To assess the reliability of the records, patients were not informed about the memory capacity of the device. We compared automatically stored blood pressure readings with the respective logbook entries to analyze deletion (under-reporting), addition (over-reporting), and precision of reporting of test results. The prevalent pattern was under-reporting, averaging 36% +/- 24% (3% to 89%), which occurred significantly more than over-reporting (9% +/- 11%; 0% to 38%). The precision of reporting (identical values at corresponding times) was 76% +/- 34% (0% to 100%). This observer error did not affect group comparisons of automatically stored values and logbook entries, although the estimated limits of agreement were wide. Blood pressure control, duration of hypertension, age, or previous use of self-measurement and patterns of logbook entries were not found to be predictive of the patients' reliability. Our results demonstrate a substantial observer error in the reporting of self-measured blood pressure values. This bias may be reduced by memory-equipped blood pressure devices.
Mengden et al. (Tue,) conducted a observational in Hypertension (n=30). Patient logbook reporting vs. Automatically stored device memory was evaluated on Accuracy and reliability of reporting (deletion, addition, and precision). Patient reporting of self-measured blood pressure in logbooks showed substantial observer error compared to device memory, with under-reporting averaging 36% and precision at 76%.