Quantifying effects of blood pressure control on neuroimaging utilization in a large multi-institutional healthcare population

Abstract

Objectives: Essential hypertension is a common chronic condition that can exacerbate or complicate various neurological diseases that may necessitate neuroimaging. Given growing medical imaging costs and the need to understand relationships between population blood pressure control and neuroimaging utilization, we seek to quantify the relationship between maximum blood pressure recorded in a given year and same-year utilization of neuroimaging CT or MR in a large healthcare population.

Methods: A retrospective population-based cohort study was performed by extracting aggregate data from a multi-institutional dataset of patient encounters from 2016, 2018, and 2020 using an informatics platform (Cosmos) consisting of de-duplicated data from over 140 academic and non-academic health systems, comprising over 137 million unique patients. A population-based sample of all patients with recorded blood pressures of at least 50 mmHg DBP or 90 mmHg SBP were included. Cohorts were identified based on maximum annual SBP and DBP meeting or exceeding pre-defined thresholds. For each cohort, we assessed neuroimaging CT and MR utilization, defined as the percentage of patients undergoing ≥1 neuroimaging exam of interest in the same calendar year.

Results: The multi-institutional population consisted of >38 million patients for the most recent calendar year analyzed, with overall utilization of 3.8-5.1% for CT and 1.5-2.0% for MR across the study period. Neuroimaging utilization increased substantially with increasing annual maximum BP. Even a modest BP increase to 140 mmHg systolic or 90 mmHg diastolic is associated with 3-4-fold increases in MR and 5-7-fold increases in CT same-year imaging compared to BP values below 120 mmHg / 80 mmHg.

Conclusion: Higher annual maximum recorded blood pressure is associated with higher same-year neuroimaging CT and MR utilization rates. These observations are relevant to public health efforts on hypertension management to mitigate costs associated with growing imaging utilization.

Fig 1. Neuroimaging utilization increases with increasing annual maximum DBP based on multi-institutional data accessed via Cosmos.

Error bars denote 95% confidence intervals based on the normal approximation to the binomial.

Fig 2. Neuroimaging utilization increases with increasing annual maximum SBP based on multi-institutional data accessed via Cosmos.

Error bars denote 95% confidence intervals based on the normal approximation to the binomial.

Fig 3. Same-year neuroimaging utilization within various age ranges increases with increasing annual maximum DBP based on multi-institutional data accessed via Cosmos.

Error bars denote 95% confidence intervals based on the normal approximation to the binomial.

Fig 4. Same-year neuroimaging utilization within various age ranges increases with increasing annual maximum SBP based on multi-institutional data accessed via Cosmos.

Error bars denote 95% confidence intervals based on the normal approximation to the binomial.

Fig 5. Age-adjusted same-year mortality rates for the DBP and SBP cohorts.

Error bars denote 95% confidence intervals based on the normal approximation to the binomial.

Fig 6. Same-year neuroimaging utilization stratified by payor type increases with increasing annual maximum DBP.

Fig 7. Same-year neuroimaging utilization stratified by payor type increases with increasing annual maximum SBP.

Fig 8. Same-year neuroimaging utilization stratified by encounter type increases with increasing annual maximum DBP.

Fig 9. Same-year neuroimaging utilization stratified by encounter type increases with increasing annual maximum SBP.