SKIP TO CONTENT
Save the date! ACG System User Conference October 26-28, 2025

DOCUMENTS

Documents

The impact of influenza vaccination on hospitalizations and mortality among frail older people

J Am Med Dir Assoc 15:256-260. National Yang-Ming University, Taipei, Taiwan OBJECTIVES: The objective of this study was to evaluate the benefits of influenza vaccination […]

Federally qualified health center efficacy study

Montpelier, VT, USA: Vermont Program for Quality in Health Care. Vermont Program for Quality in Health Care, Montpelier, VT, USA OBJECTIVE: The objective of the […]

Homecare after pediatric traumatic brain injury: what do they use and how much does it cost?

Arch Phys Med Rehabil 96:e38. University Health Network, Toronto, ON, Canada Objective(s): To determine, by sex, the predictors, types, and direct cost of publicly funded […]

Trends in abdominal aneurysm surgery, 2002-2014

Toronto, ON, Canada: Institute for Clinical Evaluative Sciences (internal report). Institute for Clinical Evaluative Sciences, Toronto, ON, Canada Methods: We conducted a population-based cohort study […]

Building a predictive model for 30-day inpatient readmission using PROC PHREG

Presented at NESUG 2012. Baltimore, MD, USA: North East SAS User Group. Department of Health Policy and Management, Bloomberg School of Public Health, Johns Hopkins […]

Adverse selection, welfare and the optimal pricing of employer-sponsored health plans

St. Paul, MN, USA: University of Minnesota and NBER. University of Minnesota, St. Paul, MN, USA We assess the welfare impact of adverse selection in […]

Patterns of regional mental illness disorder diagnoses and service use in Manitoba: a population-based study

Winnepeg, MB, Canada: Manitoba Centre for Health Policy. Manitoba Centre for Health Policy, University of Manitoba, Winnipeg, MB, Canada Mental illness is a profound problem […]

Ambulatory Care Groups: an evaluation for military health care use

Fort Sam Houston, TX, USA: United States Army Center for Healthcare Education and Studies, publication #HR 94-004. United States Army Center for Healthcare Education and […]

Models for Medicare payment system reform based on group-specific volume performance standards (GVPS)

Waltham, MA, USA: Brandeis University. Brandeis University, Waltham, MA, USA This report discusses potential policy options for Medicare based on Group-Specific Volume Performance Standards (GVPS). […]

Aging in Ontario: an ICES chartbook of health service use by older adults

Toronto, ON, Canada: Institute for Clinical Evaluative Sciences. Institute for Clinical Evaluative Sciences, Toronto, ON, Canada Recent investments by the Ontario Ministry of Health and […]

Impacto economico de las enfermedades y pacientes atendidos en atencion primaria adaptacion de los Grupos Clinicos Adjustados (ACGs) en nuestro medio

Barcelona, Spain: University of Barcelona (doctoral dissertation). Published in Spanish. University of Barcelona, Barcelona, Spain El objetivo general de este trabajo es medir el impacto […]

Outcomes of care for South Carolina Medicaid managed care enrollees, state fiscal year 2007

Final report to the South Carolina Department of Health and Human Services. Columbia, SC, USA: University of South Carolina. University of South Carolina, Columbia, SC, […]

Primary health care reimbursement based on socioeconomics or disease burden

Primärvårdsersättning efter socioekonomi eller sjukdomsbörda. [Primary health care reimbursement based on socioeconomics or disease burden. Registry study from Östergötland shows different results depending on analysis […]

Implementation of electronic medical records and preventive services: a mixed methods study

Toronto, ON, Canada: University of Toronto (masters thesis). University of Toronto, Toronto, ON, Canada The implementation of Electronic Medical Records (EMRs) may lead to improved […]

Primärvården som koordinator för de mest sjuka äldre – implikationer för mål och indikatorer

In: Karlsson AK, Winberg H, ed. På väg mot en värdefull styrning. LHC Report: #1, 2012. Stockholm, Sweden: Stiftelsen Leading Health Care:150-172. Published in Swedish. […]

Demand for health among Canadians: roles of immigration status, country of origin, and year since migration

Toronto, ON, Canada: University of Toronto (doctoral dissertation). University of Toronto, Toronto, ON, Canada This thesis investigates the effects of immigration status, country of origin, […]

Complications following total joint arthroplasty in patients with rheumatoid arthritis

Toronto, ON, Canada: University of Toronto (doctoral dissertation). University of Toronto, Toronto, ON, Canada BACKGROUND: Total joint arthroplasty (TJA) is indicated in persons with end-stage […]

Working for Better Health in Wandsworth -The ACG System’s role in transforming services through innovative care models

Working for Better Health in Wandsworth -The ACG System’s role in transforming services through innovative care models

Leicester City CCG Case Study 1

Use of ACG® System output to support practices in participating in the Unplanned Admissions DES 2014-15

Predictive Models in the ACG® System: Recalibration of Existing Models and Development of New Ones

This short report provides details of the second recalibration of the existing models and the development of new models that was carried out by the […]

Health Care Reform In the US and England

The Johns Hopkins University Health Care Reform In the US and England: Commonalities and potential contribution of case-mix & predictive risk modeling tools Jonathan Weiner, […]

Applying the ACG® System to a Retrospective Electronic Database

Applying the Johns Hopkins ACG Applying the Johns Hopkins ACG Casemix Casemix System to a Retrospective Electronic Database: A 5 to a Retrospective Electronic Database: […]

Patient Identification with Incomplete Data

DST Health Solutions Patient Identification with Incomplete Data Kelsey Rauch

Tuesday(C6)-Refining Patient Risk Assessment with Clinical Lab Results-Lemke

Refining Patient Risk Assessment with Clinical Lab Results-Klaus Lemke

Tuesday(P3)-Moving the Chronic Care Model into the Future-Wagner

Moving the Chronic Care Model into the Future Ed Wagner, MD, MPH, MACP  MacColl Center for Health Care Innovation  Group Health Research Institute 

The ACG System’s Inception

Donald Steinwachs, PhD, Professor, Health Policy and Management, Johns Hopkins Bloomberg School of Public Health goes through the history of the ACG System, the importance […]

Care Management Program Case Study-Payer

Clalit Health (an integrated delivery system in Israel) used the ACG System to identify high-risk patients for enrollment in a comprehensive complex care management program for its multimorbid population. This led to a reduction in length of time spent in the hospital, reductions in readmission rates and lower costs.

Outcomes of patients with chronic obstructive pulmonary disease diagnosed with or without pulmonary function testing

Background: A small number of people with chronic obstructive pulmonary disease (COPD) receive pulmonary function testing around the time of diagnosis. Because omitting testing increases […]

Defining and Assessing Geriatric Risk Factors and Associated Health Care Utilization Among Older Adults Using Claims and Electronic Health Records

Abstract Background: Using electronic health records (EHRs), in addition to claims, to systematically identify patients with factors associated with adverse outcomes (geriatric risk) among older […]

A Canadian Population-Based Cohort to the Study Cost and Burden of Surgically Resected Hidradenitis Suppurativa

Abstract Background: Hidradenitis suppurativa (HS) is a chronic debilitating disease with long-lasting comorbidities that impose direct and indirect costs on the health care system. However, […]

Medicaid trends in prescription opioid and non-opioid use by HIV status

Abstract   Background Pain is more common among people living with HIV (PLWH) than their counterparts; however, it is unclear whether analgesic use differs by […]

Supporting general practice to make timely decisions for better health care: a population health approach

Abstract Primary Health Networks (PHNs) are tasked to enhance the efficiency and effectiveness of general practice. Gold Coast Primary Health Network (GCPHN) has been collecting […]

Is Post-discharge Rehabilitation Timing Associated with 90-Day Readmission in Primary Total Joint Arthroplasty?

Abstract Background Physical therapy (PT) is an accepted standard of care after total joint arthroplasty (TJA) and essential to maximizing joint functionality and minimizing complications […]

Prediction of 30-day pediatric unplanned hospitalizations using the Johns Hopkins Adjusted Clinical Groups risk adjustment system

Abstract Background The Johns Hopkins ACG System is widely used to predict patient healthcare service use and costs. Most applications have focused on adult populations. […]

Impact of comprehensive care on health care use among a cohort of marginalized people living with hepatitis C in Toronto, Canada

Abstract Background The majority of new hepatitis C (HCV) cases occur among people who inject drugs. In recent years, multidisciplinary models of HCV treatment have […]

Association of Follow-Up Care With Long-Term Death and Subsequent Hospitalization in Patients With Atrial Fibrillation Who Receive Emergency Care in the Province of Ontario

Abstract Background Currently, 11% of patients seen in the emergency department for atrial fibrillation die within 1 year of the visit. Our objective was to […]

Measuring multimorbidity beyond counting diseases: systematic review of community and population studies and guide to index choice

Abstract Objectives To identify and summarise existing indices for measuring multimorbidity beyond disease counts, to establish which indices include mental health comorbidities or outcomes, and […]

Health characteristics of reproductive-aged autistic women in Ontario: A population-based, cross-sectional study

Abstract While an increasing number of girls and women are being identified with autism, we know little about the health of reproductive-aged autistic women. Our […]

The effect of frailty on postoperative readmissions, morbidity, and mortality in endometrial Cancer surgery

Abstract Objectives To determine the impact of frailty on postoperative readmission, morbidity, and mortality among patients undergoing surgery for endometrial cancer. Methods Patients with endometrial […]

Association between mental health comorbidity and health outcomes in type 2 diabetes mellitus patients

Abstract Background Type 2 diabetes mellitus (T2D) is often accompanied by chronic diseases, including mental health problems. We aimed at studying mental health comorbidity prevalence […]

Analysis of modifiable and nonmodifiable risk factors in patients undergoing pituitary surgery

Abstract OBJECTIVE Pituitary adenomas (PAs) are among the most common intracranial tumors. Understanding the clinical effects of various modifiable risk factors (MRFs) and nonmodifiable risk […]

Health care service use and costs for a cohort of high-needs elderly diabetic patients

Abstract Aims To describe the impact of diabetes comorbidities on the health care services use and costs of a cohort of elderly patients with diabetes […]

Management and outcomes of patients with chronic obstructive lung disease and lung cancer in a public healthcare system

Abstract Hypothesis There is limited data on the care and outcomes of individuals with both chronic obstructive pulmonary disease (COPD) and lung cancer, particularly in […]

Guideline interval: A new time interval in the diagnostic pathway for symptomatic cancer

Abstract Background: A standard measure of the cancer diagnostic pathway, diagnostic interval, is the time from “first presentation of cancer” to diagnosis. Cancer presentation may be […]

Impact of Frailty on Clinical and Financial Outcomes Following Minor Lower Extremity Amputation: A Nationwide Analysis

Abstract Objective Frailty has been shown to portend worse outcomes in surgical patients. Our goal was to identify the impact of frailty on outcomes and […]

The clinical impact of frailty on the postoperative outcomes of patients undergoing gastrectomy for gastric cancer: a propensity-score matched database study

Abstract Background Frailty aggregates a composite of geriatric and elderly features that is classified into a singular syndrome; literature thus far has proven its influence […]

Outcomes of SARS-CoV-2 infection in cancer versus non-cancer-patients: A population-based study in northeastern Italy

Abstract Introduction This study assesses the risk of infection and clinical outcomes in a large consecutive population of cancer and non-cancer patients tested for SARS-CoV-2 […]

Comparing and validating medication complexity from insurance claims against electronic health records

ABSTRACT BACKGROUND Patient effort to comply with complex medication instructions is known to be related to nonadherence and subsequent medical complications or health care costs. […]

Surgeon factors but not hospital factors associated with length of stay after colorectal surgery – A population based study

Abstract Aim Length of stay (LOS) after colorectal surgery (CRS) is a significant driver of healthcare utilization and adverse patient outcomes. To date, there is […]

Predicting Health Utilities Using Health Administrative Data: Leveraging Survey-linked Health Administrative Data from Ontario, Canada

Abstract Background The quality-adjusted life year (QALY) is widely used to measure health outcome that combines the length of life and health-related quality of life […]

Impact of a nurse-based intervention on medication outcomes in vulnerable older adults

Abstract Background Medication-related problems are common in older adults with multiple chronic conditions. We evaluated the impact of a nurse-based primary care intervention, based on […]

Big Data Byte: Jonathan Weiner on analytics in population health

Dr. Jonathan Weiner participated as a featured presenter in the 2015 Big Data & Health Care Analytics forum in New York City. Watch the below […]

ACG System Version 12.0

This presentation discusses the various v12.0 features such as refined risk assessment variables and enhanced analytics. Presented by Dr. Stephen Sutch. Learn more.

Family members of people with alcohol or drug dependence: health problems and medical cost compared to family members of people with diabetes and asthma

Addiction 104:203-214. Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA AIMS: To compare the medical costs and prevalence of health conditions of family […]

Comparative analysis of outcome measures used in examining neurodevelopmental effects of early childhood anesthesia exposure

Anesthesiology 120:1319-1332. Columbia University, New York, NY, USA; University of Western Australia, Perth, Australia; Princess Margaret Hospital for Children, Perth, Australia; New York State Psychiatric […]

Inequities in ambulatory care and the relationship between socioeconomic status and respiratory hospitalizations: a population-based study of a Canadian city

Ann Fam Med 12:402-407. University of Manitoba, Winnipeg, MB, Canada PURPOSE: Individuals of lower socioeconomic status have higher rates of hospitalization due to ambulatory care-sensitive […]

Neurodevelopment of children exposed to anesthesia: design of the Mayo Anesthesia Safety in Kids (MASK) study

Contemp Clin Trials 41:45-54. Mayo Clinic, Rochester, MN, USA; Baylor College of Medicine, Houston, TX, USA; National Center for Toxicological Research, Food and Drug Administration, […]

Diagnosis and treatment of incident hypertension among patients with diabetes: a U.S. multi-disciplinary group practice observational study

J Gen Intern Med 30:768-776. University of Wisconsin, Madison, WI, USA BACKGROUND: Early hypertension control reduces the risk of cardiovascular complications among patients with diabetes […]

Comorbidity burden and health services use in community-living older adults with diabetes mellitus: a retrospective cohort study

Can J Diabetes 40:35-42. University of Alberta, Edmonton, AB, Canada; Institute for Clinical Evaluative Sciences, Toronto, ON, Canada; Women’s College Hospital, Toronto, ON, Canada; McMaster […]

Exploring indicators of use of costly health services in community-dwelling adults with multiple chronic conditions

Prof Case Manag 20:3-11. Mayo Clinic College of Medicine, Rochester, MN, USA; Mayo Clinic, Rochester, MN, USA; Case Western Reserve University, Cleveland, OH, USA Although […]

Comorbidity and the use of primary care and specialist care in the elderly

Ann Fam Med 3:215-222. Department of Health Policy and Management, Johns Hopkins School of Public Health, Baltimore, MD, USA PURPOSE: The impact of comorbidity on […]

All-cause mortality and serious cardiovascular events in people with hip and knee osteoarthritis: a population based cohort study

PLoS One 9:e91286. Women’s College Hospital, Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Institute for Clinical Evaluative Sciences, Toronto, ON, Canada BACKGROUND: Because […]

Development and application of a population-oriented measure of ambulatory care case-mix

Med Care 29:452-472. Department of Health Policy and Management, Johns Hopkins University School of Hygiene and Public Health, Baltimore, MD, USA This article describes a […]

Adjusted Clinical Groups (ACGs) explain the utilization of primary care in Spain based on information registered in the medical records: a cross-sectional study

Health Policy 76:38-48. Centro de Salud Astrabudua, Consulado Bilbao, Bizkaia, Spain BACKGROUND: Previous studies have shown the validity of Adjusted Clinical Groups (ACGs) in the […]

Diabetes quality of care and outpatient utilization associated with electronic patient-provider messaging: a cross-sectional analysis

Diabetes Care 32:1182-1187. Department of Health Services, University of Washington School of Public Health and Community Medicine, Seattle, WA, USA OBJECTIVE: To test the hypothesis […]

Imputation of 10-year osteoporotic fracture rates from hip fractures: a clinical validation study.

J Bone Miner Res 25:388-392. Faculty of Medicine, University of Manitoba, Winnipeg, MB, Canada The World Health Organization (WHO) fracture risk assessment system (FRAX) allows […]

Differences in referral rates to specialised health care from four primary health care models in Klaipeda, Lithuania

BMC Fam Pract 9:63. Lund University, Department of Clinical Sciences in Malmö, General Practice/Family Medicine, Malmö, Sweden BACKGROUND: Lithuanian primary health care (PHC) is undergoing […]

Managing the gap: evaluating the impact of Medicaid managed care on preventive care receipt by child and adolescent minority populations

J Health Care Poor Underserved 21:92-111. St. Mary’s College of Maryland, St. Mary’s City, MD, USA The increased use of managed care in Medicaid warrants […]

Patient web services integrated with a shared medical record: patient use and satisfaction

J Am Med Inform Assoc 14:798-806. Center for Health Studies, Group Health Cooperative, Seattle, WA, USA OBJECTIVES: This study sought to describe the evolution, use, […]

Using the Johns Hopkins’ Aggregated Diagnosis Groups (ADGs) to predict 1-year mortality in population-based cohorts of patients with diabetes in Ontario, Canada

Diabet Med 29:1134-1141. Institute for Clinical Evaluative Sciences, University of Toronto, ON, Canada AIMS: There are limited validated methods to ascertain comorbidities for risk adjustment […]

Quantifying morbidity burdens and medical utilization of children with intellectual disabilities in Taiwan: A nationwide study using the ACG case-mix adjustment system

Res Dev Disabil 33:1270-1278. Department of Medical Affairs and Planning, Taipei Veterans General Hospital, Taipei City, Taiwan, ROC The purpose of this study was to […]

Is it necessary that some patients come to see us so often? Factors associated with primary care use in pediatrics

Gac Sanit 14:195-202. Published in Spanish. Centro de Salud de Astrabudúa (Bizkaia), Osakidetza-Servicio Vasco de Salud, Bilbao, Spain OBJECTIVES: To analyze the relationship between pediatric […]

Development of a claims-based risk score to identify obese individuals

Popul Health Manag 13:201-207. Division of General Internal Medicine, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA Obesity is underdiagnosed, hampering system-based health promotion […]

Comparison of health care expenditures among insured users and nonusers of complementary and alternative medicine in Washington State: a cost minimization analysis

J Altern Complement Med 16:411-417. Department of Health Services, University of Washington, Seattle, WA, USA OBJECTIVES: The purpose of this analysis was to compare health […]

Guided care: cost and utilization outcomes in a pilot study

Dis Manag 11:29-36. Johns Hopkins HealthCare, Glen Burnie, MD, USA Guided Care (GC) is an enhancement to primary care that incorporates the operative principles of […]

Identifying frail older people using predictive modeling

Am J Manag Care 18:e392-e397. Department of Geriatric Medicine, Maccabi Healthcare Services, Tel Aviv, Israel OBJECTIVES: To determine whether a designation of frailty using the […]

A randomized study to decrease the use of potentially inappropriate medications among community-dwelling older adults in a southeastern managed care organization

Am J Manag Care 10:761-768. Department of Medicine and Center for Healthcare Improvement, Medical College of Georgia, Atlanta, Ga, USA BACKGROUND: Despite progress in describing […]

Development and validation of a model for predicting inpatient hospitalization

Med Care 50:131-139. Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health and School of Medicine, Baltimore, MD, USA BACKGROUND: Hospitalizations […]

Involuntary unemployment and mortality in Taiwan

J Formos Med Assoc 103:900-907. Institute of Public Health, National Yang-Ming University, Taipei, Taiwan. BACKGROUND AND PURPOSE: Unemployment is known to be associated with increased […]

Case-control study of antibiotic use and subsequent Clostridium difficile-associated diarrhea in hospitalized patients

Infect Control Hosp Epidemiol 29:44-50. Permanente Medical Group, Oakland, CA, USA OBJECTIVE: To determine which antibiotics increase or decrease the risk of Clostridium difficile-associated diarrhea […]

More preventive care, and fewer emergency room visits and prescription drugs–health care utilization in a consumer-driven health plan

Benefits Q 24:46-54. Healthcare Informatics, Blue Cross Blue Shield of Minnesota, USA. Although consumer-driven health plans (CDHPs) have grown dramatically, the question of whether CDHPs […]

Assessing comorbidity using claims data: an overview

Med Care 40:IV-26-IV-35. Health Services and Economics Branch, Applied Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, MD, USA Comorbidity, […]

Pharmacy- and diagnosis-based risk adjustment for children with Medicaid

Med Care 43:1155-1159. Center for Child and Adolescent Health Policy, MassGeneral Hospital for Children, Department of Pediatrics, Harvard Medical School, Boston, MA, USA BACKGROUND: Risk […]

The influence of incidental abdominal aortic aneurysm monitoring on patient outcomes

J Vasc Surg 54:1290-1297.e2. Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada BACKGROUND: Incidental abdominal aortic aneurysms (AAAs) are identified when the abdomen is […]

Population based study of long-term rates of surgery for urinary incontinence after radical prostatectomy for prostate cancer

J Urol 188:502-506. Division of Urology, Sunnybrook Health Sciences Centre, Sunnybrook Research Institute, Toronto, ON, Canada PURPOSE: Urinary incontinence can be a significant complication of […]

Prescribing of psychotropic medications to the elderly population of a Canadian province: a retrospective study using administrative databases

PeerJ 1:e168. Faculty of Pharmacy, University of Manitoba , Winnipeg, MB, Canada BACKGROUND. Psychotropic medications, in particular second-generation antipsychotics (SGAs) and benzodiazepines, have been associated […]

Comparative safety and effectiveness of sitagliptin in patients with type 2 diabetes: retrospective population based cohort study

BMJ 346:f2267. Department of Public Health Sciences, School of Public Health, University of Alberta, Edmonton, AB, Canada OBJECTIVE: To determine if the use of sitagliptin […]

Association between fee-for-service expenditures and morbidity burden in primary care

Eur J Health Econ 15:599-610. Faculty of Health Sciences, COHERE-Centre of Health Economics Research, Institute of Public Health, University of Southern Denmark, Odense, Denmark BACKGROUND: […]

Using risk-adjustment models to identify high-cost risks

Med Care 41:1301-1312. Center for Health Research, Northwest and Hawaii, Kaiser Permanente Northwest, Portland, OR, USA BACKGROUND: We examine the ability of various publicly available […]

Predicting persistently high primary care use

Ann Fam Med 3:324-330. Division of Health Care Policy & Research, Department of Health Sciences Research, Mayo Clinic College of Medicine, Rochester, MN, USA PURPOSE: […]

Specialty use among patients with treated hypertension in a patient-centered medical home

J Gen Intern Med Division of General Internal Medicine and Geriatrics, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA BACKGROUND: Little is known about […]

One-year outcomes associated with using observation services in triaging patients with nonspecific chest pain

Clin Cardiol 37:591-596. Division of Management, Policy and Community Health, University of Texas School of Public Health, Houston, Texas. BACKGROUND: Observation services are provided in […]

Changes in office visit use associated with electronic messaging and telephone encounters among patients with diabetes in the PCMH

Ann Fam Med 12:338-343. Group Health Research Institute, Seattle, WA, USA PURPOSE: Telephone- and Internet-based communication are increasingly common in primary care, yet there is […]

Measuring morbidity in populations: performance of the Johns Hopkins Adjusted Clinical Group (ACG) case-mix adjustment system in Manitoba

Winnipeg, MB, Canada: Manitoba Centre for Health Policy. Manitoba Centre for Health Policy, Winnipeg, MB, Canada This study examined the performance of the Johns Hopkins […]

Creating meaningful composite scores for primary care

2015 North American Primary Care Research Group Annual Meeting, October 2015, Cancun, Mexico. Context: Composite scores (CSs) provide a global measure of quality. CS development […]

LinkedIn

© The Johns Hopkins University, The Johns Hopkins Hospital, and Johns Hopkins Health System.
All rights reserved. Terms of Use Privacy Statement

Back to top