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IPD Source Information

Methodology Overview

Our analysts review the full text and references of hundreds of medical journals, trade journals, audits, online databases, registries, and market investment reports each month and summarize the data into our Article Reviews. Full source citations are provided for each review. We also compile data from the most recent surveys of the National Center for Health Statistics (NCHS) in our U.S. Patient Discharges reports.

Our analysts go beyond our core sources to constantly monitor larger disease areas and therapeutic areas in which the data is hard to find. In addition, we conduct ongoing special searches for subscribers requiring broader or more specialized searches.

Article Review Sources


Our analysts review English-language medical journals that publish epidemiology-related data on an ongoing basis. Below is an abridged listing of journals we cover in specific therapeutic areas.

An aphabetical list is also available by clicking here.

Allergy and Immunology

Allergy: European Journal of Allergy and Clinical Immunology
Allergology International
Annals of Allergy, Asthma, and Immunology
International Archives of Allergy and Immunology
Journal of Allergy and Clinical Immunology


Anesthesia and Analgesia

Cardiovascular and Circulatory Medicine

American Heart Journal
American Journal of Cardiology
BMC Cardiovascular Disorders
Circulation Journal (Japan)
European Heart Journal
European Journal of Heart Failure
Heart Asia
International Heart Journal
International Journal of Cardiology
International Journal of Stroke
Journal of the American College of Cardiology
Pace (Pacing and Clinical Electrophysiology)

Critical and Emergency Care

American Journal of Emergency Medicine
Annals of Emergency Medicine
Critical Care Medicine
International Wound Journal
Journal of Trauma


BMC Dermatology
British Journal of Dermatology
International Journal of Dermatology
JAMA Dermatology
Journal of the American Academy of Dermatology
Journal of the European Academy of Dermatology and Venereology

Epidemiology, Infectious Disease, and Vaccines

American Journal of Epidemiology
American Journal of Tropical Medicine and Hygiene
Annals of Epidemiology
Clinical Infectious Diseases
Emerging Infectious Diseases
Epidemiology and Infection
European Journal of Clinical Microbiology and Infectious Diseases
European Journal of Epidemiology
Expert Review of Vaccines
Health Protection Report (England and Wales)
HIV/AIDS Surveillance Report
Human Vaccines and Immunotherapeutics
International Journal of Epidemiology
International Journal of STD and AIDS
Journal of Clinical Epidemiology
Journal of Epidemiology
Journal of Epidemiology and Community Health
Journal of Infectious Diseases
Lancet Infectious Diseases
Morbidity and Mortality Weekly Report
Preventing Chronic Diseases
Public Health Reports
Surveillance Summaries (CDC)
Weekly Epidemiological Review


Alimentary Pharmacology and Therapeutics
American Journal of Gastroenterology
Clinical Gastroenterology and Hepatology
Digestive Diseases and Sciences
Diseases of the Colon and Rectum
BMC Gastroenterology
European Journal of Gastroenterology and Hepatology
Inflammatory Bowel Diseases
Journal of Crohn's and Colitis
Journal of Gastroenterology and Hepatology
Scandinavian Journal of Gastroenterology
World Journal of Gastroenterology
World Journal of Hepatology

General and Internal Medicine

American Journal of Medicine
American Journal of Physical Medicine and Rehabilitation
American Journal of Public Health
American Journal of the Medical Sciences
Annals of Family Medicine
Annals of Internal Medicine
BMC Medicine
BMJ Open
British Medical Journal (BMJ)
Bulletin of the World Health Organization
Canadian Medical Association Journal
Chinese Medical Journal
Cleveland Clinic Journal of Medicine
IASR (Japan)
International Journal of the Medical Sciences
JAMA (Journal of the American Medical Association)
JAMA Internal Medicine
Journal of Family Practice
Journal of General Internal Medicine
Journal of Internal Medicine
Journal of the American Board of Family Medicine
Mayo Clinic Proceedings
Medical Care
Medical Journal of Australia
MMWR Surveillance Summaries
New England Journal of Medicine
PLOS Medicine
Postgraduate Medical Journal
Southern Medical Journal

Genetics and Rare Diseases

American Journal of Medical Genetics Part A
BMC Medical Genomics
Intractable and Rare Diseases Research
Genetics in Medicine
Genome Medicine
Orphanet Journal of Rare Diseases
Rare Diseases


BMC Geriatrics
Journal of Gerontology
Journal of the American Geriatrics Society

Healthcare Administration

American Journal of Managed Care
Health Affairs
Hospitals and Health Networks


British Journal of Haematology
Seminars in Hematology

Metabolism and Endocrinology

BMC Endocrine Disorders
Clinical Endocrinology
Diabetes Care
Endocrine Reviews
Journal of Clinical Endocrinology and Metabolism


American Journal of Kidney Diseases
BMC Nephrology
Clinical Nephrology
Journal of the American Society of Nephrology
Kidney International
Nephrology Dialysis Transplantation

Neurology and Psychiatry

American Journal of Psychiatry
Annals of General Psychiatry
Annals of Neurology
BMC Neurology
BMC Psychiatry
Brain and Behavior
British Journal of Psychiatry
Comprehensive Psychiatry
European Archives of Psychiatry and Clinical Neuroscience
European Journal of Neurology
European Neurology
European Psychiatry
JAMA Neurology
JAMA Psychiatry
Journal of Clinical Psychiatry
Journal of Nervous and Mental Disease
Journal of Neurology
Journal of Neurology, Neurosurgery, and Psychiatry
Journal of the American Academy of Child and Adolescent Psychiatry
World Psychiatry

Nutritional Sciences

American Journal of Clinical Nutrition
International Journal of Eating Disorders
International Journal of Obesity
Journal of Nutrition
Journal of the American Dietetic Association

Obstetrics and Gynecology

American Journal of Obstetrics and Gynecology
British Journal of Obstetrics and Gynaecology
International Journal of Gynecology and Obstetrics
Journal of Obstetrics and Gynaecology
Obstetrics and Gynecology


Annals of Oncology
Asia Pacific Journal of Clinical Oncology
BMC Cancer
British Journal of Cancer
CA -- A Cancer Journal for Clinicians
Cancer Epidemiology, Biomarkers and Prevention
European Journal of Cancer
Gynecologic Oncology
International Journal of Cancer
Journal of Clinical Oncology
Journal of the National Cancer Institute
Leukemia and Lymphoma
Seminars in Oncology


American Journal of Ophthalmology
BMC Ophthalmology
British Journal of Ophthalmology
Investigative Ophthalmology and Visual Science
JAMA Ophthalmology
Retina Today
Survey of Ophthalmology

Oral Medicine

Journal of Oral and Maxillofacial Surgery
Journal of the American Dental Association
Oral Oncology
Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology


Bone and Joint Journal
BMC Musculoskeletal Disorders
European Spine Journal
Joint Bone Spine
Journal of Bone and Joint Surgery
Journal of Bone and Mineral Research


Acta Oto-Laryngologica
Annals of Otology, Rhinology, and Laryngology
BMC Ear, Nose, and Throat Disorders
JAMA Otolaryngology--Head and Neck Surgery
Journal of Laryngology and Otology
Otolaryngology - Head and Neck Surgery

Pain Medicine

European Journal of Pain


American Journal of Pathology
Journal of Clinical Pathology


Acta Paediatrica
Archives of Disease in Childhood
Archives of Disease in Childhood (Fetal and Neonatal Edition)
BMC Pediatrics
Clinical Pediatrics
European Journal of Pediatrics
JAMA Pediatrics
Journal of Pediatrics
Pediatric Infectious Disease Journal


American Journal of Health-System Pharmacy
US Pharmacist

Pulmonary and Respiratory Medicine

American Journal of Respiratory and Critical Care Medicine
BMC Pulmonary Medicine
European Respiratory Journal

Reproductive Medicine

Family Planning Perspectives
Fertility and Sterility
International Family Planning Perspectives
Perspectives on Sexual and Reproductive Health
Reproductive Health


Annals of the Rheumatic Diseases
Arthritis and Rheumatism
Arthritis Care and Research
Arthritis Research and Therapy
International Journal of Rheumatic Diseases
Journal of Rheumatology
Scandinavian Journal of Rheumatology
Seminars in Arthritis and Rheumatism


American Journal of Surgery
Annals of Surgery
Annals of Thoracic Surgery
British Journal of Surgery
JAMA Surgery
Journal of the American College of Surgeons
Journal of Thoracic and Cardiovascular Surgery
Journal of Vascular Surgery
Plastic and Reconstructive Surgery

Transplantation and Transfusion

Transplantation Proceedings


BJU International
BMC Urology
European Urology
International Journal of Urology
Journal of Urology
Scandinavian Journal of Urology and Nephrology
World Journal of Urology

Websites, Surveys, and Associations

Agency for Healthcare Research and Quality (AHRQ)
Alan Guttmacher Institute
American Assocation of Blood Banks (AABB)
American Cancer Society (ACS)
American Heart Association (AHA)
American Hospital Association (Health Forum LLC) - Hospital Statistics (US)
American Lung Association
Annual Report of the American Association of Poison Control Centers Toxic Exposure Surveillance System (TESS)
Assisted Reproductive Technology Surveillance
British Heart Foundation - European Cardiovascular Disease Statistics
Cancer Research UK - “Cancer Stats”
Centers for Disease Control and Prevention (CDC)
Centers for Disease Control and Prevention (CDC) HIV/AIDS Surveillance Report
Centers for Medicare and Medicaid Services
Central Brain Tumor Registry of the US (CBTRUS)
EUCAN database (from the International Association of Cancer Registries)
European Centre for Disease Prevention and Control – The First European Communicable Disease Epidemiological Report
GLOBOCAN (from the International Agency for Research on Cancer)
Health Forum LLC (an affiliate of the American Hospital Association)
Healthcare Cost and Utilization Project (HCUP)
International Bone Marrow Transplant Registry and the Autologous Blood and Marrow Transplant Registry (IBMTR/ABMTR) and National Marrow Donor Program (NMDP)
International Society of Aesthetic and Plastic Surgery
Medscape Week in Review
MMWR Surveillance Summaries
National Cancer Center
National Center for Health Statistics
National Health and Nutrition Examination Survey (NHANES)
National Heart, Lung, and Blood Institute
National Institutes of Health (NIH)
National Organization for Rare Diseases (NORD)
NIH Consensus Statements
Pan American Health Organization
Plastic Surgery Information Service
Public Health Laboratory Service (PHLS)
Society for Assisted Reproductive Technology (SART)
Substance Abuse and Mental Health Services Administration (SAMHSA)
Surveillance, Epidemiology, and End Results (SEER) data
Toxic Exposure Surveillance System (TESS)
UK Renal Registry
UK Transplant
United Network for Organ Sharing (UNOS)
United States Renal Data System (USRDS) Annual Data Report
World Health Organization (WHO)

U.S. Patient Discharges

TDR Database Audit type Data source Facilities included Facilities excluded Size of audit**

Patient Volume Databases

(formerly the HIP, ER, HOP, POP)
Inpatient - (Diagnoses & Procedures) National Hospital Discharge Survey (NHDS)

Full documentation (pdf)
Short-stay hospitals (hospitals with an average length of stay for all patients of less than 30 days) or those whose specialty is general (medical or surgical) or children's general are included in the survey. Federal, military, and Veterans Administration hospitals 2010: 239 hospitals

A total of 151,551 patient records were used to the 2010 dataset.
Emergency Room (Diagnoses) National Hospital Ambulatory Medical Care Survey (NHAMCS)

Full documentation (pdf)
Hospitals with an average length of stay for all patients of less than 30 days (short-stay) or hospitals whose specialty was general (medical or surgical) or children's general were eligible. Federal hospitals, hospital units of institutions, and hospitals with less than six beds staffed for patient use. 2009: 412 Emergency Departments

A total of 34,942 patient records were used for the 2008 dataset.
Hospital Outpatient (Diagnoses) National Hospital Ambulatory Medical Care Survey (NHAMCS)

Full documentation (pdf)
Hospitals with an average length of stay for all patients of less than 30 days (short-stay) or hospitals whose specialty was general (medical or surgical) or children's general were eligible. Federal hospitals, hospital units of institutions, and hospitals with less than six beds staffed for patient use. 2009: 900 clinics within 220 outpatient departments

A total of 33,551 patient records were used for the 2008 dataset.
Physician Office (Diagnoses) National Ambulatory Medical Care Survey (NAMCS)

Full documentation (pdf)
-- Office-based, as defined by the AMA and AOA;

-- Principally engaged in patient care activities;

-- Nonfederally employed;

-- Not in specialties of anesthesiology, pathology, and radiology.
2010: 1,228 physicians responded with patient records.

A total of 31,229 patient records were used for the 2010 dataset.


National Survey of Ambulatory Surgery (Procedures) National Survey of Ambulatory Surgery (NSAS)
Full documentation (pdf)
Ambulatory surgery procedures performed in short-stay hospitals and freestanding ambulatory surgery centers. Federal, military, and Department of Veteran’s Affairs hospitals. A total of 52,233 Patient records were used for the 2006 dataset.

** Numbers in this column are unweighted. However, data output in TDR's databases are weighted to estimate discharges for all U.S. facilities that correspond to the inclusion criteria.

How does the National Hospital Discharge Survey (NHDS) differ from the National Inpatient Sample published by HCUP?

The NIS uses a larger sample and is created by combining datasets from individual states.  However, not all U.S. states are represented in the sample.  For an in-depth comparison, see: Comparative Analysis of HCUP (NIS) and NHDS Inpatient Discharge Data.

Current Medical Diagnosis and Treatment (CMDT)

CMDT is the most comprehensive, reliable, and timely reference available to answer common questions in everyday clinical practice. Written in a concise, easy-to-read style, the text covers all aspects of outpatient and inpatient care as well as authoritative descriptions of new developments in medicine. It includes information on over 1,000 diseases and disorders with an emphasis on prevention and cost-effective treatments. CMDT also features updated information on drug dosages and updated therapeutic options in HIV, including an approach to multi-drug antiretroviral therapies. CMDT is updated annually.