13.3 Research Methodology, Biostatistics & Evidence-Based Practice

ABPMR Physical Medicine and Rehabilitation Board Exam Study Guide Exam

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1 Chapter 1: Introduction & Exam Overview

1.1 ABPMR Part I Exam Overview & Format 1.2 Board Review Strategy & Content Blueprint Breakdown

2 Chapter 2: Musculoskeletal Medicine

2.1 Shoulder & Upper Extremity Diagnostics 2.2 Knee, Hip & Lower Extremity Conditions 2.3 Spine Pathology, Radiculopathy & Myelopathy 2.4 Inflammatory Arthritis, Tendinopathies & Concussion 2.5 Bone Health, Osteoporosis & Metabolic Bone Disease 2.6 Thoracic Outlet Syndrome & Peripheral Nerve Entrapment 2.7 Fracture Rehabilitation & Immobilization Complications 2.8 Overuse Tendinopathies & Regenerative Medicine 2.9 Gait Analysis & Abnormal Gait Patterns

3 Chapter 3: Spinal Cord Injury Rehabilitation

3.1 ASIA Examination & Impairment Scale 3.2 Spinal Cord Injury Syndromes 3.3 Autonomic Dysreflexia & Acute Complications 3.4 Neurogenic Bladder, Bowel & Secondary Complications

4 Chapter 4: Stroke & Neuromuscular Rehabilitation

4.1 Stroke Vascular Syndromes & Acute Assessment 4.2 Stroke Motor Recovery & Hemiplegic Complications 4.3 Spasticity Assessment & Multimodal Management 4.4 ALS, GBS, CIDP & Neuromuscular Disease Rehab 4.5 Multiple Sclerosis & Demyelinating Disease Rehabilitation 4.6 Parkinsonism, Movement Disorders & Functional Neurologic Disorder

5 Chapter 5: Electrodiagnostics (EMG/NCS)

5.1 Nerve Conduction Studies Principles & Physics 5.2 Needle Electromyography & MUAP Analysis 5.3 Mononeuropathies & Radiculopathy Patterns 5.4 Neuromuscular Junction Disorders & Myopathies

6 Chapter 6: Traumatic Brain Injury

6.1 TBI Severity Classification, Glasgow Coma Scale, and Pathophysiology 6.2 Rancho Los Amigos Levels of Cognitive Functioning and Disability Rating Scale 6.3 Neurobehavioral Sequelae and Agitation Management 6.4 Concussion Evaluation, Vestibular-Ocular Dysfunction, and Return-to-Play/Work Protocols

7 Chapter 7: Chronic Pain & Interventional Spine

7.1 Fluoroscopic Spine Interventions 7.2 Opioid Stewardship & Controlled Substance Compliance 7.3 Complex Regional Pain Syndrome, Fibromyalgia & Myofascial Pain 7.4 Spinal Cord Stimulation & Intrathecal Therapy

8 Chapter 8: Amputee Rehabilitation & Prosthetics

8.1 Amputation Surgical Levels & Medicare K-Levels 8.2 Socket Designs & Suspension Systems 8.3 Prosthetic Feet & Microprocessor Knee Mechanisms 8.4 Post-Amputation Care, Residual Limb & Phantom Pain

9 Chapter 9: Pediatric Rehabilitation

9.1 Cerebral Palsy Classification & GMFCS 9.2 Spina Bifida & Myelomeningocele Management 9.3 Muscular Dystrophies & Neuromuscular Disease in Children 9.4 Pediatric Brachial Plexopathy & Congenital Disorders

10 Chapter 10: Prosthetics, Orthotics & Assistive Technology

10.1 Lower Limb Orthoses — AFOs & KAFOs 10.2 Spinal & Upper Extremity Orthoses 10.3 Upper Limb Prosthetics — Body-Powered vs Myoelectric 10.4 Wheelchairs, Seating Systems & Pressure Mapping

11 Chapter 11: Medical Rehabilitation & Outcomes

11.1 Dysphagia Assessment & Management 11.2 Neurogenic Bladder & Bowel Management 11.3 Pressure Injuries & Wound Management 11.4 Outcome Measures & Medical Complications 11.5 Cancer Rehabilitation & Oncologic Rehabilitation 11.6 Burns, Endocrine/Metabolic & Medical Complications Rehabilitation

12 Chapter 12: Cardiopulmonary Rehabilitation

12.1 Cardiac Rehabilitation Phases & Metabolic Equivalents 12.2 Pulmonary Rehabilitation & COPD Management

13 Chapter 13: Foundational Rehabilitation Concepts

13.1 Kinesiology, Biomechanics & Functional Anatomy 13.2 Rehabilitation Pharmacology & Medication Management 13.3 Research Methodology, Biostatistics & Evidence-Based Practice 13.4 Nutrition, Metabolism & Energy Expenditure in Rehabilitation 13.5 Diagnostic Procedures: Imaging, MSK Ultrasound, Urodynamics & Neuropsych Assessment

13.3 Research Methodology, Biostatistics & Evidence-Based Practice

Key Takeaways Explain This Topic AI

Study designs span a hierarchy from case reports (weakest) to randomized controlled trials and systematic reviews/meta-analyses (strongest); blinding, randomization, and allocation concealment reduce bias in RCTs.

Sensitivity (true positive rate) and specificity (true negative rate) characterize a test independent of prevalence; positive/negative predictive values depend on disease prevalence.

A p-value is the probability of observing data as extreme as observed if the null hypothesis is true; a 95% confidence interval that excludes the null (e.g., 0 for differences, 1 for relative risks/odds ratios) indicates statistical significance.

Evidence-based practice integrates the best research evidence, clinical expertise, and patient values; GRADE and levels of evidence rate recommendation strength.

Last updated: July 2026

Research Methodology, Biostatistics & Evidence-Based Practice

Research and statistics is a Domain A applied-science topic that recurs in item stems requiring interpretation of study design, diagnostic test performance, and effect estimates.

Study Design Hierarchy Case report/series < Case-control < Cohort < Randomized Controlled Trial < Systematic Review / Meta-analysis

Design Strength Key Feature / Limitation

Case-control Observational, retrospective Odds ratio; prone to recall and selection bias; efficient for rare diseases

Cohort Observational, prospective/retrospective Relative risk; temporal relationships; confounding
RCT Experimental Randomization, blinding, allocation concealment reduce bias; gold standard for therapy
Systematic review/meta-analysis Synthesis Pooled estimates; heterogeneity must be assessed (I-squared)

Bias to recognize: selection, recall, measurement/observer, publication (in meta-analysis). Confounding is mitigated by randomization (RCT) or multivariable adjustment (observational).

Diagnostic Test Performance

Metric Definition

Sensitivity (Sn) Proportion with disease who test positive (true positive rate); high sensitivity → rules OUT (SnNOUT)

Specificity (Sp) Proportion without disease who test negative (true negative rate); high specificity → rules IN (SpPIN)

PPV Proportion testing positive who truly have disease; rises with prevalence
NPV Proportion testing negative who truly lack disease; falls with prevalence

Likelihood ratio LR+ = sensitivity/(1-specificity); LR- = (1-sensitivity)/specificity; combine with pretest probability Disease + Disease -

Test + a (TP) b (FP)
Test - c (FN) d (TN)
Sensitivity = a/(a+c); Specificity = d/(b+d); PPV = a/(a+b); NPV = d/(c+d)

Sensitivity and specificity are intrinsic to the test and do not change with prevalence; PPV and NPV do change with prevalence.

Hypothesis Testing & Confidence Intervals

Null hypothesis (H0): no effect/difference; alternative (H1): an effect exists.

p-value : probability of observing results as extreme as observed if H0 is true; a small p (commonly <0.05) leads to rejecting H0, but does not measure effect size or clinical importance.

Type I error (alpha) : false positive (finding an effect that does not exist); Type II error (beta) : false negative (missing a real effect); power = 1 - beta.

95% confidence interval : range that, over repeated samples, would contain the true parameter 95% of the time; if it excludes the null (0 for absolute differences, 1 for ratios), the result is statistically significant at the 0.05 level.

Effect size : clinical importance differs from statistical significance—a large trial can detect trivial differences; report and interpret effect sizes and CIs.

Common Statistical Tests

Comparison Test
Two group means (parametric) t-test
>2 group means ANOVA
Categorical association Chi-square / Fisher exact (small samples)
Paired/repeated measures Paired t-test, repeated-measures ANOVA
Correlation Pearson (linear), Spearman (nonparametric)
Time-to-event Kaplan-Meier, log-rank, Cox regression
Evidence-Based Practice (EBP)

EBP integrates (1) the best available research evidence, (2) clinical expertise, and (3) patient values and preferences. GRADE rates the certainty of evidence and strength of recommendations, considering risk of bias, inconsistency, indirectness, imprecision, publication bias, and magnitude of effect. Appraisal tools (CASP) structure critical reading. Candidates should distinguish statistical significance from clinical importance and interpret CIs and LRs.

Observational vs Experimental Designs & Confounding

Observational studies (cohort, case-control) cannot fully exclude confounding even with adjustment; RCTs, through randomization, balance known and unknown confounders. When RCTs are unethical or impractical (e.g., effect of a harmful exposure), well-designed observational studies with techniques like propensity-score matching provide evidence, interpreted with caution. Recognizing residual confounding is essential to applying evidence to individual patients.

Likelihood Ratios & Clinical Application

Likelihood ratios combine test performance with pretest probability to generate post-test probability, independent of prevalence-driven PPV/NPV limitations: Pretest Probability ──► Pretest Odds ──► x LR ──► Post-test Odds ──► Post-test Probability

An LR+ >10 or LR- <0.1 meaningfully shifts probability. This framework helps the physiatrist decide when an additional test (e.g., imaging before injection) changes management, versus when it is low-value.

Effect Size & Clinical Significance

Statistical significance (p<0.05) does not imply clinical importance. A large trial can detect a trivial between-group difference; conversely, a small trial may miss a clinically important effect (underpowered). Candidates should interpret effect sizes (mean difference, relative risk, odds ratio, NNT) and confidence intervals together, distinguishing "statistically detectable" from "clinically meaningful." Number-needed-to-treat (NNT = 1/absolute risk reduction) communicates practical impact.

Critical Appraisal & Applying Evidence

Appraisal Question What to Check
Validity Randomization, blinding, allocation concealment, ITT analysis
Importance Effect size, confidence interval, NNT, clinical relevance
Applicability Patient similarity, setting, feasibility, patient values

Evidence-based practice integrates appraisal with clinical expertise (judging applicability, technical skill) and patient values (preferences, goals, risk tolerance). GRADE rates certainty of evidence (high/moderate/low/very low) and strength of recommendations (strong/weak), incorporating consistency, directness, precision, and magnitude. The physiatrist applies this to rehab interventions—many of which are complex, multimodal, and benefit from individualized application of group-level evidence.