Rothman Index: 26 EHR Variables & Acuity Score

Q: What is rothman index?

The Rothman Index (Rothman et al., 2013; commercialized by PeraHealth/Spok) is a continuous, real-time patient acuity score ranging from 100 (unimpaired health) down to -91 (extreme physiological derangement) calculated automatically from 26 EHR variables: 6 vital signs, 11 head-to-toe nursing flowsheet assessments, the Braden Scale score, cardiac rhythm, and 7 time-decayed laboratory values.

Q: How is rothman index used in clinical research and healthcare?

Hospitals integrate the Rothman Index into Epic, Oracle Health, MEDITECH, and Altera Sunrise EHRs to visualize continuous patient acuity trend lines (`PeraTrend`), trigger early warning alerts for sepsis and cardiopulmonary deterioration (`RI < 65` or `RI < 40`), guide ICU step-down and discharge readiness decisions, and risk-adjust inpatient clinical outcomes research.

Informational reference for hospital clinical informatics teams, rapid response system (RRS) medical directors, and predictive analytics researchers. This guide summarizes peer-reviewed validation studies and EHR integration specifications and does not provide individual patient care instructions.

Inpatient quality officers, critical care nursing informaticists, and clinical decision support (CDS) engineers use this reference to understand the Rothman Index (RI) (commercialized by PeraHealth, now part of Spok), inspect its 26 underlying EHR vital sign, nursing flowsheet, and laboratory variables, interpret its -91 to 100 continuous acuity trajectory, and compare it with vital-sign-only early warning scores such as MEWS and NEWS2.

What Is the Rothman Index? (Short Answer)

The Rothman Index (RI)—developed by Michael J. Rothman, Steven I. Rothman, and Joseph Beals IV (Journal of Biomedical Informatics, 2013)—is a continuous, general-purpose measure of inpatient physiological condition computed automatically in real time from routine electronic health record (EHR) data. Scored on a linear scale from 100 (unimpaired physiological status) down to a theoretical minimum of -91 (severe multi-system physiological derangement), the Rothman Index subtracts empirically derived excess 1-year post-discharge mortality risk weights across 26 clinical variables spanning vital signs, head-to-toe nursing flowsheet assessments, the Braden Scale pressure injury score, cardiac rhythm, and 7 routine blood laboratory tests.

The 26 EHR Input Variables of the Rothman Index

Unlike traditional early warning scores that rely solely on 5 to 7 vital signs, Rothman et al. (2013) demonstrated that nursing head-to-toe physical assessments captured every shift in EHR flowsheets carry independent, high-signal prognostic value for physiological deterioration. Each variable’s deviation from normal is mapped to an excess mortality risk function (computed via cubic spline regression against 1-year post-discharge mortality), summed, and rescaled from 100 downward:

EHR Data Category	Number of Variables	Specific Clinical Inputs & Temporal Weighting Rules
1. Vital Signs	6 variables	Temperature, Systolic Blood Pressure, Diastolic Blood Pressure, Heart Rate (Pulse), Respiration Rate, and Peripheral Oxygen Saturation (`SpO₂`)
2. Head-to-Toe Nursing System Assessments	11 binary system flags	Structured nursing flowsheet pass/fail (met vs. did-not-meet normal standard) across: Cardiac, Respiratory, Gastrointestinal, Genitourinary, Neurological, Skin/Tissue, Safety/Fall Risk, Peripheral Vascular, Food/Nutrition, Psychosocial, and Musculoskeletal systems
3. Braden Scale & Cardiac Rhythm	2 variables	Braden Scale total score (`6–23`) (assessing sensory perception, moisture, activity, mobility, nutrition, and friction/shear) plus Cardiac Rhythm classification (e.g., sinus rhythm, atrial fibrillation, paced)
4. Laboratory Biomarkers (Time-Decayed)	7 lab variables	Creatinine, Blood Urea Nitrogen (BUN), Chloride, Potassium, Sodium, White Blood Cell (WBC) count, and Hemoglobin; laboratory risk contributions linearly decay to zero over 48 hours if not re-drawn

Rothman Index Score Interpretation and Clinical Deterioration Thresholds

Every time a new vital sign, nursing assessment, or laboratory result is filed in the EHR (transmitted via HL7 v2 ORU^R01 / flowsheet interfaces or HL7 FHIR Observation resources), the PeraHealth engine recalculates the patient’s Rothman Index and plots it on a continuous time-series trend graph (PeraTrend / PeraWatch):

RI = 100: Maximum possible score; all 26 vital sign, nursing, and laboratory parameters are within their lowest-risk reference ranges.
RI ≥ 65 (Green / Low-to-Moderate Acuity): Typical baseline range for stable general medical-surgical floor inpatients.
RI 40 to 64 (Yellow / High Acuity Warning): Indicates significant physiological compromise; crossing below RI = 65 (or experiencing a rapid relative drop of ≥ 30% within 24 hours) commonly triggers automated nurse-driven sepsis screens or rapid response team (RRT) huddles.
RI < 40 (Red / Critical Acuity): Associated with high 24-hour mortality risk and ICU-level physiological instability (crossing below RI = 40 or a ≥ 40% drop triggers immediate physician and RRT escalation).

Rothman Index vs. MEWS vs. NEWS2 vs. Epic Deterioration Index (EDI)

In peer-reviewed comparative studies (such as Finlay, Rothman, & Smith, Journal of Hospital Medicine, 2014), the Rothman Index is evaluated alongside three alternative inpatient early warning systems:

Model / Score	Input Variables	Score Range & Polarity	Published 24-Hour Mortality Discrimination & Characteristics
PeraHealth Rothman Index (RI)	26 EHR variables (6 vitals, 11 nursing assessments, Braden score, rhythm, 7 labs)	`-91 to 100` (lower score = worse condition)	`AUC = 0.93` for 24-h mortality (Finlay et al., 2014); FDA 510(k)-cleared physiological monitoring / CDS software; captures subtle nursing-detected decline before vital signs crash
Modified Early Warning Score (MEWS)	5 variables: Systolic BP, Heart Rate, Respiratory Rate, Temperature, AVPU neurological score	`0 to 14` (higher score = worse condition)	`AUC = 0.82` for 24-h mortality (Finlay et al., 2014); simple bedside arithmetic table, but misses laboratory and nursing assessment trends
National Early Warning Score 2 (NEWS2)	7 variables: Respiratory Rate, SpO₂ (Scale 1 vs. hypercapnic Scale 2), Supplemental O₂, Systolic BP, Pulse, Consciousness (ACVPU), Temperature	`0 to 20` (higher score = worse condition)	Standardized across UK NHS hospitals (Royal College of Physicians, 2017); high sensitivity for acute respiratory/septic decompensation
Epic Deterioration Index (EDI)	Ordinal logistic regression model embedded in Epic using vitals, nursing assessments (GCS, Braden), labs, age, and oxygen requirements	`0 to 100` (higher score = higher deterioration risk)	Native to Epic Hyperspace; subject to local site threshold calibration and external validation requirements

How Is the Rothman Index Used in Clinical Research and Healthcare?

In hospital operations and health services research, the Rothman Index drives four primary clinical workflows:

Early Detection of Subtle Physiological Deterioration & Sepsis: Because nurses document changes in mentation, skin perfusion, and gastrointestinal/urinary function hours before hypotension or tachycardia develops, a downward-sloping Rothman Index trajectory alerts charge nurses and rapid response teams inside clinical decision support systems (CDSS).
ICU Transfer Readiness and Discharge Timing: Tracking whether an ICU patient’s Rothman Index has stabilized above unit-specific thresholds reduces premature floor transfers (“ICU bounce-backs”) and informs post-discharge readmission risk score stratification.
Pediatric Rothman Index (pRI): Age-adjusted vital sign and laboratory splines extend the Rothman Index to pediatric medical-surgical and PICU populations.
ONC HTI-1 Predictive DSI Governance (45 CFR § 170.315(b)(11)): When embedded inside certified EHRs, predictive acuity indices are governed by ONC HTI-1 Final Rule transparency requirements for intervention risk management and model validation attributes.

Frequently Asked Questions

What is rothman index?

The Rothman Index (Rothman et al., 2013; commercialized by PeraHealth/Spok) is a continuous, real-time patient acuity score ranging from 100 (unimpaired health) down to -91 (extreme physiological derangement) calculated automatically from 26 EHR variables: 6 vital signs, 11 head-to-toe nursing flowsheet assessments, the Braden Scale score, cardiac rhythm, and 7 time-decayed laboratory values.

How is rothman index used in clinical research and healthcare?