Department of Biomedical Informatics University of Utah Practice-Based Evidence: A New Paradigm for Comparative Effectiveness Research October 23, 2014 by Susan D.
Download ReportTranscript Department of Biomedical Informatics University of Utah Practice-Based Evidence: A New Paradigm for Comparative Effectiveness Research October 23, 2014 by Susan D.
Department of Biomedical Informatics University of Utah Practice-Based Evidence: A New Paradigm for Comparative Effectiveness Research October 23, 2014 by Susan D. Horn, Ph.D Institute for Clinical Outcomes Research 699 East South Temple, Suite 215 Salt Lake City, Utah 84102 801-466-5595 (V) 801-718-9149 (C) [email protected] www.isisicor.com 1 History of the Problem • How best to treat the patient in your office right now? • “Scientific studies” (i.e., RCTs) provide imperfect guidance • Clinical medicine is untidy; innumerable variables describe patients, providers, practices, and outcomes • Must consider clinical variability of patient populations, intervention combinations, and outcomes 2 Objectives of Presentation 1. Present examples of findings from PBE studies in stroke, traumatic brain injury, and RSV infections in children 2. Describe PBE study designs used in these examples and compare PBE to other designs used in CER 3 Post-Stroke Rehabilitation Study 2001 – 2003; 1,161 patients Study Objectives PBE study designed to discover what combinations of medical devices, therapies, medications, feeding approaches, and their interactions worked best for specific types of stroke patients treated in realworld practices. 4 Post-Stroke Rehabilitation Study Trans-Disciplinary Project Clinical Team • • • • • Physicians Nurses Social Workers Psychologists Physical Therapists • • • Occupational Therapists Recreation Therapists Speech/Language Pathologists 5 Post-Stroke Rehabilitation Study Examples of OUTCOME VARIABLES • Change in FIM score • Deep vein thrombosis • Length of rehab stay • Major bleeding • Discharge disposition • Pulmonary embolism • Contracture • Pressure ulcer • Death • Pneumonia 6 Post-Stroke Rehabilitation Study Examples of PROCESS VARIABLES • • • • • Medications • Intensity, frequency, and duration of OT interventions • Intensity, frequency, and duration of SLP interventions • Other therapy interventions and dosage Nutritional process Pain management Time to first rehab Intensity, frequency, and duration of PT interventions 7 Post-Stroke Physical Therapy Form P hysical T herapy R ehabilitation A ctivities 6649 Patient ID: Date of Therapy Session: S a m p l e / / Time session begins: Therapist: : INTERVENTION CODES D uration of A ctivity: Neuromuscular Interventions: Enter in 5 minute increments. 01. Balance training 02. Postural awareness Pre-Functional Activity 03. M otor learning 04. PNF Bed M obility 05. NDT 06. Gait with body weight support 07. Involved upper extremity addressed Sitting 08. Constrained induced movement therapy Musculoskeletal Interventions: 09. Strengthening Transfers 10. M obilization 11. PROM /Stretching 12. M anual Therapy Sit-to-Stand 13. M otor Control Cardiopulmonary Intervention: 14. Breathing W heelchair M obility 15. Aerobic/Conditioning exercises Cognitive/Perceptual/Sensory Interventions: 16. Cognitive training Pre-gait 17. Perceptual training 18. Visual training G ait 19. Sensory training Education Interventions: 20. Patient Advanced Gait 21. Family/Caregiver 22. Staff Equipment Interventions: Community M obility 23. Prescription/Selection 24. Application 25. Fabrication Intervention not related 26. Ordering Modality Interventions: 27. Electrical Stimulation 28. Biofeedback 29. Ultrasound Pet Therapy: 30. Use of dog 31. Use of other animal Assistive Device: 32. Ankle dorsi flex assist 33. Cane - Large base 34. Cane - Small base 35. Cane - Straight 36. Crutches - Axillary 37. Crutches - Forearm 38. Crutches - Small base forearm 39. Dowel 40. Grocery cart 41. Hemirail 42. Ironing board 43. KAFO 44. Lite gait 45. 46. M irror Parallel bars Interventions: Enter one intervention code per group of boxes. to functional activity Intervention #2 not related to functional activity Platform (parallel bars or FW W ) 48. Standing frame 49. Steps (various heights) 50. Step ladder 51. Swedish knee cage 52. Swiss ball 53. Tray table 54. W alker - FW W 55. W alker - Hemiwalker 56. W alker - Rising Star 57. W alker - Standard 58. W heelchair O ther: 59. Co-T reat: 47. Area Involved/non-functional: 60. Upper Extremity 61. Lower Extremity 62. Trunk 63. Head/Neck Disciplines: No. of minutes: Patient Assessm ent: Formal Assessment (initial, re-evaluation, discharge): minutes Home Evaluation: minutes W ork Site Evaluation: minutes Physical T herapy T im e: Physical Therapist PT Assistant PT Aide/Tech PT Student minutes minutes minutes minutes G roup Physical T herapy T im e: PT Group/Dovetail: minutes Enter the number of each that participated in the Group PT: Patients Therapists Assistants Aides/Techs Students 8 Traumatic Brain Injury What treatments are associated with better outcomes at rehabilitation discharge for patients with traumatic brain injury? 9 Children Hospitalized with RSV What treatments are associated with better outcomes for children hospitalized with RSV infections, controlling for child differences? 10 What We Have and What We Need We have Efficacy trials that determine whether an intervention produces a specified result(s) under well controlled conditions in a selected population – includes randomized controlled trials (RCTs). We need Effectiveness trials that measure outcomes of an intervention under “real world” conditions in an unselected clinical population. Hypotheses and study designs for an effectiveness trial are formulated based on conditions of routine clinical practice and on outcomes essential for clinical decisions. 11 Databases for Effectiveness Trials • RCT databases • Large claims databases, e.g., Medicare, Medicaid, CDC • HMO or VA databases from claims and electronic medical records • Specific condition registries, such as arthritis registry • Practice-based evidence study registries PBE studies overcome limitations of RCTs (that limit patient types and treatments) More detailed patient, process, and outcome evaluation than is possible with 12 traditional registries or large claims datasets RCT Databases for Comparative Effectiveness Research • RCT databases – gold standard for efficacy and value of interventions • Advantages include: High internal validity Causal inferences can be made since patients with known confounders are excluded and randomization eliminates unknown confounders 13 RCT Databases for Comparative Effectiveness Research (cont) • Limitations include: Small sample sizes – too small to detect uncommon risks Follow-up periods too short to assess long-term benefits/risks Higher-risk patients are excluded typically; limited external validity Level of monitoring is more rigorous than done in routine practice High rates of treatment discontinuation 14 Non-RCT Databases for Comparative Effectiveness Research • Advantages include: Cover thousands to millions of people including minority and elderly Ability to provide treatment exposures and adverse events, including hospitalizations and mortality, over extended periods of time Provide population and subpopulation-based estimates for various outcomes Better suited to evaluate safety as opposed to effectiveness Many exist in electronic form so some data elements may be exported for use in comparative effectiveness research analyses 15 Non-RCT Databases for Comparative Effectiveness Research • Limitations include: Restricted ability to capture patients’ severity of illness, functional and cognitive status, health behaviors (other than smoking), pain, etc. These can be important unmeasured confounders Restricted access for CER unless researcher is part of organization that owns the data Often required variables are in text format so are not exportable 16 Issues to Address in CER Studies • Minimizing Bias in drawing conclusions from existing databases • Capturing variation in patients • Capturing variation in interventions/ intervention combinations • Capturing variation in outcomes 17 Basic Problem in Non-Randomized Studies • Confounding by Indication « Therapies are administered in non-random fashion « Prognostic characteristics influence therapy used « Recipients of therapy are at high risk for outcomes « Users differ from non-users in key respects 18 Propensity Score Theory to Address Confounding by Indication • PS is a multivariable scoring method that collapses multiple observed predictors of treatment into a single value (a probability score) » PS represents the probability that a subject with given characteristics receives specified treatment » Used to: match, stratify, or model » Assumption is by matching on propensity score, it removes confounding by components included in the score » Sensitive to unobserved predictor variables such as missing severity of illness measures 19 Overcoming Selection Bias/ Confounding by Indication • Statistical adjustments: –Matching –Propensity score or instrumental variables –Covariate adjustments (Severity of Illness) • Ongoing debate about the adequacy of adjustments 20 PBE Methodology What makes this approach different? Why do a PBE study? 21 History of PBE • Started with development of Comprehensive Severity Index (CSI) to measure risk-adjusted outcomes at The Johns Hopkins Hospital • CSI found to explain up to 50% of the variation in outcomes of cost, LOS, mortality • Found patients with the similar CSI scores for a condition could have very different treatments • This stimulated development of PBE study design to account for patient heterogeneity treatment heterogeneity outcome heterogeneity 22 CER Issues Addressed Using PBE • Both patients and providers report data • Data come from existing EMR with standardized structured data elements about patient characteristics, treatments, processes, patient-reported data, and multiple outcomes • Data are part of routine documentation, so not an ‘add-on’ • Rapid patient accrual since documentation is standard of care • Longitudinal and ongoing 23 CER Issues Addressed Using PBE (cont) • Patient comparability is addressed with the Comprehensive Severity Index (CSI): disease-specific, physiologic-based, >2,200 criteria, >5,500 disease-specific criteria sets • CSI addresses confounding by indication and selection bias • Database includes all treatments with date/dose/intensity/route. Many details collected in point-of care (POC) documents. • Can assess drug and non-drug combination therapies • Findings of PBE-CER are more readily translated into practice 24 Components of Practice-Based Evidence Designs Standardize documentation for : Process Factors • Patient Education and Management Strategies • Interventions and surgeries • Medications Control for: Patient Factors • Psychosocial/demographic Factors • Co-occurring Conditions • Severity of Illness and Injury • Genetic information • Measured at Multiple Points in Time Measure: Primary Outcomes • • • • • • Clinical Health Status Functional Cost/LOS/Encounters Discharge Disposition Post-discharge Outcomes 25 7 Signature Features of PBE Studies 1. Hypotheses can be focused or broad 2. All interventions are considered to determine the relative contribution of each 3. Broad patient selection criteria maximize generalizability and external validity 4. Detailed characterization of the patient by robust measures of patient severity, genetic information, and functional status 26 7 Signature Features of PBE Studies 5. Patient differences controlled statistically rather than through randomization 6. Facility and clinical/patient buy-in through use of trans-disciplinary Clinical Practice Team 7. Strength of evidence built through the research process PBE findings are more generalizable and transportable than RCT findings 27 PBE Study Hallmarks • Decisions are made by front-line clinicians vs. researchers • “Bottom-up” vs. “Top-down” approach • Guidance from researchers (scientific advisory board) and patient experience 28 PBE Study Hallmarks –Non-experimental: Follows outcomes of treatments actually prescribed –Inclusive: Uses patient populations undergoing routine clinical care –Pragmatic: Uses actual clinical outcomes –Lower Cost than RCTs –Faster than RCTs 29 Practice-Based Evidence Study Design • High external validity - Includes essentially all patients with specific condition or in specific setting(s) - Captures confounders that could affect relevant treatment responses - Reduces accidental associations between treatments and outcomes 30 Components of Practice-Based Evidence Designs Standardize documentation for : Process Factors •Patient Education and Management Strategies •Interventions and surgeries •Medications Control for: Patient Factors •Psychosocial/demographic Factors •Co-occurring Conditions •Severity of Illness and Injury •Measured at Multiple Points in Time Measure: Primary Outcomes •Change in CSI/discharge CSI •Discharge Disposition •Length of Stay •Post-discharge Outcomes 31 Examples of Severity Systems to address Selection Bias/Confounding by Indication Diagnostic/Procedure Based Systems • Clinical definition of severity • Body Systems Count • Charlson Comorbidity Index (1-yr death) Physiologic/Clinically Based Systems • 2 Apache II & III (ICU death) • 2 Medisgroups (Atlas) (hosp death) • 3 Disease Staging (hosp death) • Patient Management Categories (hosp death) • Resource definition of severity • Case Mix Groups[CMGs] (rehab LOS, $) • Acuity Index Method (LOS) • APR DRGs (hosp $) • Patient Management Categories (hosp $) • Refined DRGs (hosp LOS, $) CSI® 32 Comprehensive Severity Index (CSI®) used to account for selection bias or confounding by indication • Severity defined as “physiologic complexity presented to medical personnel due to the extent and interactions of a patient’s diseases” • Disease-specific: 5,500 disease-specific groups; over 2,200 distinct criteria. ICD-9 codes trigger disease-specific patient signs, symptoms, and physical findings used to score disease-specific and overall severity levels • • • No treatments used as criteria Comprehensive (all diseases) Clinically credible: computes disease-specific and overall severity levels • Can measure severity at multiple time points • Allows statistical comparison of interventions without confounding by severity of illness 33 CSI Severity Indicators Physiological signs and symptoms of a disease - Vital signs - Laboratory values - Radiology findings - Other physical findings Severity indicators are specific to each disease based on ICD-9-CM coding 34 Pneumonia Criteria Set 480.0-486; 506.3; 507.0-507.1; 516.8; 517.1; 518.3; 518.5; 668.00-668.04; 997.3; 112.4; 136.3; 055.1 CATEGORY 1 2 3 Cardiovascular pulse rate 51-100; ST segment changes-EKG; systolic BP 90mmHg pulse rate 100-129; 41-50; PACs, PAT, PVCs-EKG; systolic BP 80-89mmHg pulse rate 130; 31-40; systolic BP 61-79mmHg pulse rate 30; asystole, VT, VF, V flutter; systolic BP 60 mmHg Fever 96.8-100.4 and/or chills 100.5-102.0 oral; 94.0-96.7 102.1-103.9; 90.1-93.9 and/or rigors 104.0 90.0 Labs ABGs pH 7.35-7.45 pH >7.46 7.25-7.34 pH 7.10-7.24 pH 7.09; pO2 51-60mmHg pO2 50mmHg WBC 11.1-20.0K/cu mm; 2.4-4.4K/cu mm; bands 10-20% WBC 20.1-30.0K/cu mm; 1.0-2.3K/cu mm; bands 21-40% WBC 30.1K/cu mm; 1.0K/cu mm; bands 40% chronic confusion acute confusion unresponsive 9-11 6-8 5 Radiology Chest X-Ray or CT Scan infiltrate and/or consolidation in 1 lobe; pleural effusion infiltrate and/or consolidation in >1 but 3 lobes; infiltrate and/or consolidation in >3 lobes; cavitation or lung necrosis Respiratory dyspnea on exertion; stridor; rales 50%/3 lobes; decreased breath sounds 50%/3 lobes; positive for fremitus; stridor hemoptysis NOS; blood tinged or purulent or frothy sputum cyanosis present dyspnea at rest; rales >50%/ 3 lobes; decreased breath sounds >50%/ 3 lobes apnea absent breath sounds >50%/ 3 lobes Hematology pO2 61mmHg WBC 4.5-11.0K/cu mm; bands <10%; Neuro Status Lowest Glasgow coma score 12 white, thin, mucoid sputum 4 frank hemoptysis 35 Copyright 2006. Susan D. Horn. All rights reserved. Do not quote, copy or cite without permission. Stroke Criteria Set page 1 430-438.9, 648.6-648.64, 671.5-671.54, 674-674.04 Category Indicator Digestive Nausea/Vomiting No nausea or Neurology Neurological Status No unresponsiveness or confusion GCS vomiting 2 4 N/A Chronic confusion GCS>=12 GCS=9-11 GCS=6-8 GCS<=5 Seizures Focal tremors/Seizures NOS Focal/Petit Mal Seizures Grand Mal/Status Epilepticus NOS Status Epilepticus w/ >2 Hrs Drug therapy Pupil Reaction Normal Pupil Reaction Unilateral Pupil Dilation Coordination/Balance Severe Ataxia N/A N/A Aphasia Unsteady on Feet/Clumsiness Dizziness/Mild to Moderate NOS Ataxia Sensation Alteration NOS Complete loss of Sensation/Parathesia or Dysesthesia No Aphasia Mild Aphasia Bilateral Pupil Dilation N/A Dysarthria No/mild Dysarthria Dysphonia Dysarthria Incomprehensible Speech No Speech Dysphagia Dysphagia NOS Unable to swallow liquids Unable to swallow solids N/A Headache Headache NOS, No Headache Moderate/severe headache Intense headache N/A Copyright Vomiting 3 Persistent Vomiting Acute confusion Sensation alteration Pain 1 2006. Susan D. Horn. All rights reserved. Do not quote, copy or cite without permission. Unresponsive Moderate/Severe Aphasia Global Aphasia 36 Stroke Criteria Set page 2 430-438.9, 648.6-648.64, 671.5-671.54, 674-674.04 Category Indicator Respiratory Dyspenea Breathing Difficulties NOS Dyspnea on exertion Dyspnea at Rest N/A Rales No Rales Rales <=50% /<3 Lobes Rales >=50% />=3 lobes N/A Breath Sounds No decreased breath sounds Decreased Breath in <=50% / <3 lobes Decreased Breath in >=50% Absent Breath sounds />=3 lobes in >50% />=3 lobes Apnea No Apnea N/A N/A Senses Perceptual impairment No perceptual impairment Acute Decline in perceptual N/A impairment Vitals Highest Systolic BP <=180 mm Hg Highest Diastolic BP <=99 mm Hg Chronic Perceptual impairment requiring external/internal cues 181-219 mm Hg 100-109 mm Hg >=220 mm Hg >=110 mm Hg N/A N/A Lowest Systolic BP >=90 mm Hg 80-89 mm Hg 61-79 mm Hg <=60 mm Hg Highest Pulse rate <=99 Beats/min 100-129 Beats/min >=130 Beats/min N/A Lowest Pulse Rate >=51 Beats/min 41-50 Beats/min 31-40 Beats/min <=30 Beats/min Highest Temp <=100.4 Oral F >=100.5 Oral F N/A N/A Lowest Temp >=96.8 Oral F <=96.7 Oral F N/A N/A O2 Saturation No supplemental Oxygen, O2 Oxygen 22-50%, able to obtain Oxygen> 50% and able to Sat >= 90 O2 Sat >=90 Obtain O2 Sat >= 90% or Oxygen 22-50% and unable to obtain O2 sat >=90% No EKG Ectopy, Non Bigeminy/ 6 PVCs/min, SVT sustained Ventricular trigeminy/Quadrigeminy/Atrial Junctional ectopic Tachycardia fibrillation tachycardia EKG Rhythm Copyright 1 2 2006. Susan D. Horn. All rights reserved. Do not quote, copy or cite without permission. 3 4 Apnea Oxygen >50% and unable to obtain O2 Sat >=90 Runs of ventricular tachycardia 37 Post-Stroke Rehabilitation Study 2001 – 2003; 1,161 patients Study Objectives PBE study designed to discover what combinations of medical devices, therapies, medications, feeding approaches, and their interactions worked best for specific types of stroke patients treated in realworld practices. 38 Outcome: Discharge Motor FIM Severe Stroke – Full Stay General Assessment – Age PT Interventions – Formal assessment – Bed mobility + Mild motor impairment + Gait + Admission Motor FIM + Advanced gait + Admission Cognitive FIM – Black race OT Interventions + Home management SLP Interventions – Swallowing – Orientation + Reading comprehension Medications General Interventions – Days onset to rehab + Enteral feeding – Anti-Parkinsons – Modafinil – Old SSRIs + Atypical antipsychotics 39 Outcome: Discharge Motor FIM Severe Stroke–1st 3 hour Therapy block only General Assessment PT Interventions OT Interventions SLP Interventions – Age – Bed mobility + Home management st – Severe motor impairment time in 1 3 hrs + Gait time in 1st 3 + Admission Motor FIM hrs + Admission Cog. FIM + Advanced gait + No Dysphagia time in 1st 3 hrs + Neurotropic Impairments Medications General treated with meds Interventions – Other Antidepressant – Days onset to rehab – Old SSRIs + LOS + Atypical antipsychotics Horn et al., Arch Phys Med Rehabil 2005;86(12 Supplement + Enteral feeding 40 2):S101-S114 Policy Changes from Stroke PBE Study Early Rehabilitation Admission – get patient into rehabilitation as soon as possible after stroke onset; possibly start in Neuro ICU Early gait in PT – start gait as soon as possible after rehab admission; put patient in harness on treadmill for safety Early Feeding – continue or start enteral nutrition at rehab admission if patient is not able to eat full meals Use Opioids for Pain – continue or start opioids at rehab 41 admission if patient misses therapy due to pain Traumatic Brain Injury What treatments are associated with better outcomes at rehabilitation discharge for patients with traumatic brain injury? 42 TBI Admission FIM Cognitive Subgroups (N=2130) Ns decrease due to non-consent for follow up, death, or incarceration Adm FIM Cognitive N during Rehab N at 3 months N at 9 months Score <=6 339 286 262 Score 7-10 374 312 302 Score 11-15 495 411 394 Score 16-20 408 326 311 Score >=21 504 401 373 Total 2120* 1742** 1649*** *N=10, **N=6, ***N=7 Missing Admission FIM cognitive score 43 43 Point-of-Care (POC) documentationPhysical Therapy 44 Discharge Rasch-Adjusted FIM Motor Regression: Variance Explained Step R² Adm Cog Adm Cog Adm Cog Adm Cog Adm Cog <=6 7-10 11-15 16-20 >=21 Pat/Inj 0.38 0.48 0.48 0.54 0.71 Pat/Inj + POC total 0.41 0.49 0.48 0.56 0.72 Pat/Inj + POC act/ LOE 0.74 0.70 0.62 0.62 0.76 Pat/Inj + meds 0.41 0.48 0.48 0.55 0.72 0.74 0.70 0.63 0.63 0.76 0.74 0.71 0.63 0.65 0.78 Pat/Inj + POC act/ LOE + meds Pat/Inj + POC act/ LOE + meds + sites 45 45 All Regressions Summary: Patient and Injury Significant Covariates Red = negative coeff, p<.05; Green = positive coeff, p<.05 Covariate FIM Cog FIM Motor Age Avg LOE Inj to Adm Cog <=6 Black Race Rehab Length of Stay (LoS) Discharge to Home (dcH) Cog 11-15 Cog 16-20 dcC LoS dcM dcM dcC dcH fuM fuC dcM dcC dcH fuM fuC LoS dcM dcC fuM HS, No Dplma BI CSI non-BI CSI Cog 7-10 dcM LoS dcC dcM dcH fuC dcM dcH fuM fuC dcM dcC dcH dcM dcC fuM fuC LoS dcM dcC dcH fuM fuC dcM dcC dcH fuM LoS dcM fuM fuC fuC fuM fuC LoS LoS LoS LoS dcH LoS dcM fuM LoS fuM Discharge FIM Motor (dcM) 9-Month FIM Motor (fuM) LoS dcM dcC LoS dcM fuM dcM dcH fuM LoS dcM dcC dcH fuM fuC LoS fuM Cog >=21 dcC LoS dcM LoS dcM dcC dcH fuM fuC dcC fuC LoS fuM fuM fuC LoS fuM Discharge FIM Cognitive (dcC) 9-Month FIM Cognitive (fuC) LoS dcH LoS dcM fuM 46 All Regressions Summary: Regressions Summary: Treatment Significant Covariates Red = negative coeff, p<.05; Green = positive coeff, p<.05 Covariate Adm Cog <=6 OT Education/Sexuality Min/Wk dcH fuM fuC Adm Cog 7-10 Adm Cog 11-15 Adm Cog 16-20 Adm Cog >=21 dcH LoS dcH OT Home IADLs Min/Wk dcM dcH OT Physical Impairments Min/Wk dcM fuM dcM fuM dcM fuM PT Advanced Gait, Gait, Community Mobility, Stairs Min/Wk dcM fuM dcM dcH dcM fuM fuC LoS dcM PT Equip Mgmt, WC/Bed Mobility, Casting, Sitting, Trnsfrs, Develop Seq Min/Wk dcM LoS LoS dcM dcC dcM dcH dcM dcC PT Formal Assessment Min/Wk LoS fuM LoS fuM LoS dcH fuM LoS ST Education Min/Wk dcH LoS dcH fuC LoS dcH dcC dcH dcH ST Basic Motor/Speech Min/Wk dcM dcM fuM LoS dcM dcC fuM ST Problem Solving, Math, Money, Memory, Orientation Min/Wk dcM dcC fuM fuC % Stay Atypical Antipsychotics LoS dcM dcC Rehab Length of Stay (LOS) 9-Month FIM Motor (fuM) Discharge FIM Motor (dcM) 9-Month FIM Cognitive (fuC) dcM dcC fuM dcM dcC Discharge FIM Cognitive (dcC) Red = negative coeff, p<.05 fuC Discharge to Home (dcH) Green = positive coeff, p<.05 47 Children Hospitalized with RSV What treatments are associated with better outcomes for children hospitalized with RSV infections, controlling for child differences? 48 Pediatric Bronchiolitis Study Outcome = Cost n=722; Assessment - Age in months (.0001) + MCSIC (.0001) R2=0.73 Procedures + Admitted to PICU (.0001) + Arterial line (.04) + Central line (.003) + Continuous nebulization (.0002) + Interaction: chest pt & atelectasis (.005) + Intubation (.0001) + Ipratropium bromide (.005) + Lasix (.0001) + Ribavirin (.0001) + Steroids (.0003) Willson, et al. PEDIATRICS 2001;108(4):851-855. 49 Prematurity and RSV Hospital Outcomes Significant Differences by Gestational Age Groups 33-35 week GA infants had highest hospital resource use < 32 wks 33-35 wks 36 wks > 37 wks p-value Intubation 21.4% 38.7% 20% 12.1% 0.002 ICU LOS 5.8 days 7.7 days 4.2 days 3.8 days 0.021 Hospital LOS 6.8 days 8.4 days 4.9 days 4.1 days <0.0001 Admitted to ICU 39.3% 48.4% 30.0% 27.9% 0.101 HX of Hosp. for RSV /Bronchiolitis 14.3% 16.1% 6.7% 6.1% 0.137 50 RSV Hospital Outcomes and Policy Changes Conclusions • 33-35 week GA infants had highest hospital resource use • 36 week infants have risk similar to full term infants • Changed guidelines for immunoprophylaxis for 33-35 week infants • Changed guidelines for intubation – try ‘stimulating’ first 51 Summary • PBE methodology provides a structured way to design studies of patients in routine care settings • PBE studies develop comprehensive databases of patient, treatment, and outcome differences • PBE findings associated with better outcomes are easily transferable for use in other sites because all patients with a condition can be included in a PBE study 52