B

Evidence Review Strategy

This appendix presents the committee’s approach to identifying and evaluating the scientific literature reviewed in addressing the committee’s statement of task. In addressing its task of identifying types of health-care utilizations that might be good proxies for “listing-level” severity and examining factors that affect the use of health-care services, committee members collaborated with staff to identify key words, and to define and refine the search strategy. The committee used an iterative process in conducting the literature searches. In total, the committee and staff screened more than 60,000 articles from the peer-reviewed scientific literature and selected 708 for careful review. Additionally, for background information and to address the task order objective of providing a general description of the health-care delivery system, the committee searched relevant government and nongovernment research organization websites. The committee’s search included papers published in the past 10 years.

The committee’s search strategies are described in this appendix.

LITERATURE SEARCH STRATEGY: HEALTH-CARE UTILIZATIONS AS PROXIES FOR IMPAIRMENT SEVERITY

In January 2016, the PubMed database was searched using a combination of key words related to health-care utilizations, impairment severity, and disability.

Key words searched in combination with the National Library of Medicine’s Medical Subject Headings (MeSH) keywords for each body system in the Social Security Administration’s Listing of Impairments included

• “Health care utilization”[All Fields] OR “Healthcare utilization”[All Fields]
• “Hospitalization”[Mesh] OR (“Emergency Service, Hospital/statistics and numerical data”[Mesh] OR “Emergency Service, Hospital/trends”[Mesh] OR “Emergency Service, Hospital/utilization”[Mesh])
• (“Disabled Persons/nursing”[Mesh] OR “Disabled Persons/rehabilitation”[Mesh] OR “Disabled Persons/standards”[Mesh] OR “Disabled Persons/statistics and numerical data”[Mesh] OR “Disabled Persons/surgery”[Mesh] OR “Disabled Persons/therapy”[Mesh] OR “Disabled Persons/trends”[Mesh] OR “Disabled Persons/utilization”[Mesh])

Additionally, the following key words were searched without combining with MeSH terms for body systems:

• “Work disability”[All Fields]
• (“Primary Health Care/utilization”[Mesh] AND “Chronic Disease”[Mesh])

The following filters were applied:

• Last 10 years (ending February 13, 2017)
• English language
• Adults 19 through 65 years of age

The initial search resulted in 36,606 papers. The staff’s screening resulted in a final count of 800 papers.

Staff screened papers for relevance to the statement of task. The following topics were screened in:

• Affordable Care Act
• Disability
• Disparities in health care (diagnosis, admissions, treatment, etc.)
• Factors that affect return to work
• Functional status
• Gender disparities
• Health care laws
• Health care utilizations
• Hospital utilizations
• Hospitalizations
• Length of stay
• Measures of disability
• Medicare/Medicaid
• Predictors of disease severity/Measures to predict severity
• Predictors of emergency department visits
• Predictors of hospital readmission
• Racial disparities
• Rehabilitation
• Re-hospitalizations/readmissions
• Work disability

Populations and topics screened out included

• Adolescents
• Children
• Drug treatments
• Drug trial outcomes
• Elderly
• Hospitalizations due to childbirth
• Hospitalizations for influenza, pneumonia, virus infections, C. difficile
• Infants
• Not American
• Patient perceptions of facilities, treatment, doctors/nurses
• Prenatal hospitalizations

• Safety and efficacy of surgery, surgical procedures
• Studies from foreign countries
• Surgical procedure comparisons
• Surgical procedures
• Treatment (surgical, drug) comparisons

The screened-in papers were categorized into health-care utilizations by body system and types of factors affecting health-care use. The committee members then examined abstracts in their areas of expertise. Their subsequent screening resulted in a final count of 575 articles. The most common categories of health-care utilization found in this body of literature were cardiovascular, mental health, neurologic, and respiratory.

After reading the full text of the 575 articles retrieved from the search, the committee members developed an additional search strategy to capture articles they believed might have been missing from the original search. The new topics and key words included

• Additional concepts of impairment severity: “Injury Severity Score OR Trauma Severity Indices OR Severity of Illness Index OR Abbreviated Injury Scale OR Simplified Acute Physiology Score OR Patient Acuity OR Risk Adjustment OR APACHE OR Neoplasm Grading OR severity[tiab] OR mortality”
• Ability to work: “Employment OR work[MAJR] OR unemployment OR public assistance OR work[ti]”
• Musculoskeletal injuries: “Wounds and Injuries”[Mesh]
• Medications, devices, and telehealth: “Prescription Drugs”[Mesh], (“Durable Medical Equipment”[Mesh] OR “Infusion Pumps”[Mesh] OR “Radiation Equipment and Supplies”[Mesh] OR “Airway Management”[Mesh] OR “Catheterization”[Mesh] OR “Renal Dialysis”[Mesh]), “Telemedicine”[Mesh]

Those additional searches were performed in June 2017, applying the same filters as the original search, resulting in 24,309 unique hits after deduplication with the original search. From those 24,309 titles, staff identified 445 that were potentially useful to the statement of task. The committee then carefully reviewed those abstracts and kept 133 articles.

In sum, the committee screened in 708 articles out of 60,915 found in the two searches. Those 708 articles were carefully reviewed to determine whether they could be used to inform an association between health-care utilizations and impairment severity. The selected papers (a total of 80) are discussed in Chapter 4 and Appendix C.

LITERATURE SEARCH STRATEGY: BACKGROUND READING AND HEALTHCARE DELIVERY SYSTEM

In addition to PubMed, the following government and nongovernment research organizations’ websites were searched for background materials on disability, health-care utilization, and changes in the health-care delivery landscape relevant to the task order objective:

• Agency for Healthcare Research and Quality (AHRQ)
• American Medical Association (AMA)
• Cochrane Reviews
• Congressional Research Service (CRS)
• Dartmouth Atlas of Healthcare

• Government Accountability Office (GAO)
• Health Affairs
• Journal of Occupational and Environmental Medicine
• Kaiser Family Foundation (KFF)
• Lexis Law Reviews
• Mathematica Policy Research
• National Academies of Sciences, Engineering, and Medicine (the National Academies)
• National Center for Health Statistics (CDC-NCHS)
• RAND Corporation
• Social Security Bulletin
• US Congressional Budget Office (CBO)
• US Social Security Administration (SSA)
• World Health Organization (WHO)

Staff searched these websites using the following terms:

• “Health care utilization”
• “Disability” OR “Disabled Persons”
• “Patient Protection and Affordable Care Act”
• “Delivery of Health Care”
• “Medical homes”
• “Patient-Centered Care”
• “Bundled payments”
• “Health services”
• “Social security”