ICD-9-CM Diagnosis and Procedure Coding
The health care industry has experienced enormous change over the centuries. A change that will have a major impact on the entire industry is the implementation of the ICD-10 coding system as the standard code set under HIPAA for coding conditions and hospital procedures. The compliance date for implementation of ICD-10 was set for October 1, 2013. However, the Department of Health and Human Service (DHHS) has published a final rule that delays the ICD-10 compliance date to October 1, 2014. Hospital coding and billing professionals are required to have an understanding of the ICD-9-CM coding system and will need to transition to ICD-10. In an effort provide current and future knowledge required for hospital billing and coding professionals, this section will present concepts on both systems.
The objective of this chapter is to provide an overview of the history and purpose of coding medical conditions (diagnosis) and significant procedures using ICD-9-CM. A review of how coding relates to documentation, medical necessity, claim form submission, and reimbursement will demonstrate the importance of coding conditions and procedures in the hospital. The content of the ICD-9-CM coding manual is outlined to show how the coding system is organized. A discussion of ICD-9-CM coding conventions is important to understand how the conventions are used to communicate instructions to the coder. The chapter will close with a review of the basic steps of coding using ICD-9-CM diagnosis and procedure codes to provide an enhanced understanding of coding using this system. We will explore coding of diagnosis and procedures using the ICD-10, HCPCS Level I CPT and HCPCS Level II Medicare National coding systems in the next three chapters.
The evolution of classification systems for coding medical conditions dates back to the 17th century, when systems were originally developed to track the number of deaths in children. The classification and coding of medical conditions (diseases) began in England with the work of John Graunt. The London Bills of Mortality was developed by John Graunt in an attempt to estimate the proportion of live-born children who died before reaching the age of 6 years. As centuries passed, the attempts to classify causes of death and diseases continued. Many systems were developed, such as the International List of the Causes of Death, American Nomenclature of Diseases, International Classification of Diseases (ICD), Standard Nomenclature of Diseases and Operations (SNDO), and International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM). Figure 6-1 illustrates the evolution of diagnosis classification systems. Three major diagnosis classification systems that have been used over the years are the International List of the Causes of Death, the International Classification of Diseases (ICD), and the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM). The ICD-9-CM is the standard coding system used today to code patient conditions and significant procedures. Legislation was passed that requires the replacement of ICD-9-CM with the International Classification of Diseases, 10th Revision (ICD-10) diagnosis and procedure coding system, effective October 1, 2014.
The International List of the Causes of Death is a classification system of causes of death that was based on the London Bills of Mortality. A committee chaired by Jacques Bertillon developed the International List of Causes of Death using the London Bills of Mortality. The International List of the Causes of Death was presented at the International Statistical Institute and was adopted in 1893. Several countries adopted the list during the 19th century. Six revisions were made to the International List of the Causes of Death through 1948, and the sixth revision included a name change to the International Classification of Diseases.
The International Classification of Diseases (ICD) is a classification system that was used to collect data regarding the causes of death for statistical purposes. It was a revised version of the International List of the Causes of Death. The ICD was published by the World Health Organization (WHO). The Interim Commission of the WHO was given the responsibility for the sixth revision and also for the establishment of a list of causes of morbidity for international use. In 1948, WHO published ICD-6, which was a combined classification of causes of death (mortality) and disease (morbidity). With this publication came internationally accepted rules for selecting the underlying cause of death. The National Committee on Vital and Health Statistics (NCVHS) was established to serve as a liaison between national statistical institutions and WHO. From 1948 to today, there have been several revisions of the ICD. Information about WHO can be viewed on its Web site at www.who.int.
During the 1950s, hospitals began to describe diseases and procedures using the ICD-7. A revision was made in 1962 that included the first “Classification of Operations and Treatments” for hospital use. In 1968, the United States Public Health Service published ICD-8, and later the Commission on Professional and Hospital Activities (CHA) published the hospital adaptation of the ICD-A based on both the original ICD-8 and ICDA-8. The ICD-A system provided greater detail for coding of hospital and morbidity data. The hospital adaptation of the ICDA-8 was published in 1973, and it was referred to as the H-ICDA. The International Classification of Diseases (ICD-8) was the coding system used for coding diseases until the late 1970s, when the 9th revision of the ICD was published by the WHO. The United States clinically modified ICD-9 and adopted it as the diagnosis classification system for the United States in 1979. The modified version is known as the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM).
The International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) is the standard coding system currently used to describe a patient’s condition, injury, illness, disease, or other reasons the patient is receiving health care services and significant procedures performed during a hospital inpatient visit. Diseases listed in the ICD-9 were primarily acute and related to conditions resulting from infectious diseases. The types of conditions seen in Europe were different from those in the United States. A modification to the ICD-9 was required to include more detailed information regarding diseases and procedures that would be more reflective of the conditions seen in the United States. The ICD was “clinically” modified to enhance the classification and collection of morbidity data and for indexing medical records. The Department of Health and Human Services (DHHS) published the modified version of the ICD-9, called the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM), in 1979. The ICD-9-CM is the standard coding system currently used in the United States by hospitals and other providers to describe a patient’s condition, injury, illness, disease, or other reason the patient is receiving health care services. The ICD-9-CM classification allows advanced applications using the data for research, education, and administration of all aspects of health care such as indexing of patient records based on diagnosis and monitoring of health care costs. The ICD-9-CM allows for the collection of data regarding morbidity, mortality, and hospital procedures.
The term morbidity refers to the patient’s illness or disease. ICD-9-CM Volumes I and II are a classification of patient conditions, including signs, symptoms, illness, injury, diseases, and other reasons patients seek health care services. Data collected through ICD-9-CM can be retrieved and used to track diseases for various reasons such as the identification of possible epidemics or linking certain conditions with environmental factors. The term mortality refers to death. ICD-9-CM also classifies patient conditions that may be the cause of death. Tracking of patient conditions using ICD-9-CM also helps to identify other factors that contribute to death or health risk factors. Significant procedures performed in the hospital during a hospital stay are coded using ICD-9-CM Volume III procedure codes. Surgery is an example of a significant procedure. Data collected using Volume III can be used to conduct research or analysis of patient conditions and outcomes of treatments for those conditions.
Maintenance and update of the ICD-9-CM is the result of a collaborative effort of members of the ICD-9-CM Coordination and Maintenance Committee. The committee consists of representatives from four organizations: the National Center for Health Statistics (NCHS), the Centers for Medicare and Medicaid Services (CMS), the American Hospital Association (AHA), and the American Health Information Management Association (AHIMA). The organizations are referred to as cooperating parties. Table 6-1 outlines the cooperating parties and responsibilities of each organization. Information regarding the ICD-9-CM Coordination and Maintenance Committee can be viewed on their Web site at www.cdc.gov/nchs/icd/icd9cm_maintenance.htm.
|National Center for Health Statistics (NCHS)|
|Centers for Medicare and Medicaid Services (CMS)|
|American Hospital Association (AHA)|
|American Health Information Management Association (AHIMA)|
Data from Abdelhak M, Grostick S, Hanken MA, and associates (Eds): Health information: management of a strategic resource, ed 4, St Louis, 2012, Saunders.
The International Classification of Diseases, 10th Revision (ICD-10) is the standard code set for coding conditions and hospital procedures under HIPAA that is scheduled to replace ICD-9-CM effective October 1, 2014. ICD-10 was published in 1993 by the World Health Organization (WHO). The clinically modified version of ICD-10, referred to as ICD-10-CM, is the system that is scheduled to replace the ICD-9-CM Volume I and II for coding conditions. The ICD-10-PCS will replace ICD-9-CM Volume III procedure codes used for coding hospital significant procedures. The ICD-10 is currently used in many European countries. The United States has passed legislation requiring the implementation ICD-10. The Department of Health and Human Services released a final rule on January 16, 2009 mandating implementation of ICD-10 effective October 1, 2013. More recent legislation contains language that delays the compliance date to October 1, 2014. ICD-10 information can be viewed on the CDC Web site at www.cdc.gov/nchs/icd/icd10cm.htm.
Coding is the assignment of numeric or alphanumeric codes to all health care data elements of inpatient and outpatient care. All coding systems are encompassed in this definition. Coding systems are designed to provide a standardized system for describing and classifying data. The use of coding classification systems provides an efficient method to collect, track, research, and analyze specified data. Diagnosis coding is the process of translating written descriptions of signs, symptoms, illness, injury, diseases, conditions or other reasons for health care services, documented in the patient’s medical record, into codes. The purpose of diagnosis coding is to describe patient conditions and to explain the medical necessity for services and items provided, to third-party payers.
The process begins when the patient arrives at the hospital with a health care issue(s) that requires attention or for a service involving health care status. Chief complaint is the term used to describe the main reason (medical condition or symptom) why the patient is seeking health care services. A clinical interview is conducted with the patient for the purpose of obtaining information regarding the patient’s chief complaint and the history of the present illness. Details about the chief complaint can include when the condition occurred, how bad the condition is, and if it gets worse during certain activities or at particular times. Information regarding other conditions that may relate to the main condition is also obtained. The physician or other provider reviews the history, performs an examination, and prepares a plan of care. The written descriptions of the patient’s signs, symptoms, conditions, illness, injury, disease, or other reason for the visit, as well as procedures, services, and items, are recorded in the patient’s medical record. The coder translates descriptions of medical conditions into diagnosis codes. Information in the patient’s medical record that is used for diagnosis coding is illustrated in Figure 6-2.
Coded health care data was originally intended for use in research and study. Today the value of such data has expanded beyond just the classification of diseases. The primary key to reimbursement and statistical analysis by hospitals, insurance companies, health care facilities, and other relevant businesses is coded health care data. The resulting codes serve two major purposes: (1) statistical, in which patient information is aggregated by code number; and (2) clinical, in which the codes assigned to patient information are used individually. Statistical uses of codes include the study of etiology (cause) and incidences of disease, health care planning, and quality control of health care. The clinical use of codes includes completion of claim forms for reimbursement and indexing individual patient records; both are significant applications in the United States. Quality coding is critical to create an accurate and reliable data base for budgeting, clinical research, credentialing, peer review, education, financial analysis, marketing, patient care, quality assurance and risk management statistics, strategic planning, utilization management, and other internal or external facility purposes.
Data collected through the use of the ICD-9-CM coding system are used in a number of ways, as outlined in Figure 6-3. Various organizations and other entities such as government agencies, research organizations, medical associations, and insurance companies use ICD-9-CM data. Data collected are used for purposes such as research, education, and administration.
Researchers can monitor various treatments provided for specific conditions to determine outcomes. Research data are also used to study conditions and develop new treatments and technology. By monitoring these data, researchers can identify various risk factors related to specific procedures, services, or items. Analysis of health care data is critical in predicting trends in the health care industry.
Education of health care professionals can be enhanced through knowledge gained by analyzing ICD-9-CM data related to conditions and treatments. New treatments, supplies, and medications can be monitored for assessment of outcomes, both positive and negative. These data can also be used to identify and target specific educational needs of the public, such as risk factors related to heart disease or breast cancer. Standards for the prevention and treatment of disease are developed as a result of research using data from various coding systems.
There are various administrative uses of data collected from coding systems. Data can be used to evaluate, monitor, and pay for health care services. Utilization of services is a major focus area of data analysis to ensure quality of care and to control health care costs. Data are used to measure and assess the quality of health care services. The development and implementation of policies and procedures related to the provision of patient care services and payment for those services are the result of analysis of ICD-9-CM data. Many payers use data collected through these systems to determine appropriate services provided for specific conditions and to make payment determinations.
The Centers for Disease Control and Prevention (CDC) and the Centers for Medicare and Medicaid Services (CMS) are examples of two organizations that depend on the data collected through the use of ICD-9-CM and other coding systems for purposes of research, education, and administration.
The Centers for Disease Control and Prevention (CDC) is an agency of the U.S. government that provides facilities and services for the investigation, identification, prevention, and control of disease. The CDC is primarily concerned with communicable diseases, environmental health, and foreign quarantine activities. The CDC also works with state and local agencies, and it provides consultation, education, and training on communicable disease issues. For example, the CDC has established recommendations (standards) called “Universal Precautions” that specify how to minimize the risk of contracting communicable diseases such as acquired immunodeficiency syndrome (AIDS). The CDC uses ICD-9-CM coded data for many reasons, such as the identification of potential epidemics, including severe acute respiratory syndrome (SARS) or anthrax, and to predict trends regarding disease. Information regarding the CDC can be obtained from the Web site at www.cdc.gov/nchs/icd/icd9cm.htm.
The Centers for Medicare and Medicaid Services (CMS) is an agency within the Department of Health and Human Services that is responsible for the administration of Medicare and Medicaid programs. Data from ICD-9-CM are used by the CMS for many purposes, such as utilization and monitoring of health care costs and reimbursement. The government is one of the largest payers for health care services, and CMS is responsible for ensuring appropriate utilization of health care services and controlling health care costs. ICD-9-CM codes provide explanations for why services were provided. They are used by providers to communicate with payers regarding the medical necessity of services provided. CMS must also monitor health care costs for the Medicare and Medicaid programs to ensure that federal budgets are in balance. Reimbursement methods implemented under the Prospective Payment System (PPS) were developed using data from various coding systems. For example, Medicare Severity-Diagnosis Related Groups (MS-DRG) was developed through the classification of diseases, and payments are determined based on that classification. Information regarding CMS can be obtained from the Web site at www.cms.gov.
The ICD-9-CM is the standard coding system used by providers and facilities to describe a patient’s condition, injury, illness, disease, or other reasons the patient is receiving health care services. The coding of signs, symptoms, illness, injury, conditions, diseases, or other reasons that a patient seeks health care services requires knowledge of medical terminology, anatomy and physiology, pharmacology, and coding principles and guidelines. To code effectively, it is first important to have an understanding of how diagnosis coding relates to documentation, medical necessity, claim forms, and reimbursement (Figure 6-4).
Documentation is the term used to describe information regarding the patient’s condition, treatment, and response to treatment. This information is recorded in the patient’s medical record. The patient’s medical record is the foundation for coding. The Golden Rule in coding is IF IT IS NOT DOCUMENTED, DO NOT CODE IT. When coding patient conditions it is necessary to read the record to identify the condition(s) that is being treated and the condition(s) that can affect treatment. A code or codes are then selected from the ICD-9-CM manual that accurately describe the statement in the medical record. Examples of information recorded in the patient’s medical record and the code assignments are illustrated below. Each example illustrates the conditions that are identified for code assignment.
The challenge for coders is to be absolutely certain the code assignment represents what is in the record. It is important that the coder does not read into the scenario and code a condition that is not documented appropriately. If the record lacks specific information required to select a code, the coder should pursue more specific information from the physician or other provider. Remember, coders should always follow good coding habits, such as WHEN IN DOUBT, QUERY THE PHYSICIAN.
Medical necessity is the term used to describe procedures or services performed that are reasonable and necessary to address the patient’s medical condition. Medical necessity guidelines are generally determined based on standards of medical care. Payer guidelines regarding medical necessity will vary by payer. Coding conditions is the process used to communicate the condition(s) for which the patient is seeking health care services. Codes selected should be at the highest level of specificity in order to describe the patient’s condition completely and to establish medical necessity.
The CMS-1500 and CMS-1450 (UB-04) are the two universal claim forms used for submission of charges to payers for reimbursement. The primary claim form used by hospitals is the CMS-1450 (UB-04); however, there may be circumstances when a CMS-1500 is required. The CMS-1450 (UB-04) contains 81 fields, referred to as form locators (FL). Codes that describe services provided are listed on the claim form. Diagnosis codes that explain the patient’s condition or other reason why the services were provided are also required on the claim form. Figure 6-5 illustrates CMS-1450 (UB-04) fields designated for reporting conditions and procedures using ICD-9-CM codes. The codes assigned for Mr. Jammes’s case in Example #2 are reported as follows: 722.0 “Displacement of cervical intervertebral disc” is reported in FL 67 and FL 69 since the herniated disc is the admitting and principal diagnosis. The external cause of injury code E881.00 “Fall on or from ladder” is reported in FL 72a. Diagnosis codes reported on the claim form may represent the principal diagnosis, other secondary diagnoses, admitting diagnosis, patient’s reason for visit diagnosis, or an external cause.
The principal diagnosis is the condition determined after study to be chiefly responsible for the admission. Study refers to the examination and other diagnostic testing used to determine the diagnosis. Figure 6-6 illustrates the principal diagnosis code assignment for the medical record of Daniel Steins. The patient presented with chest pain; however, the condition determined after study is atherosclerosis, and therefore 414.01 “Coronary atherosclerosis of native coronary artery” is recorded as the principal diagnosis in FL 67.
A complication is a disease or condition that develops during the course of a hospital stay. Complications may prolong the patient’s length of stay, usually by 1 day in 75% of cases. Complications generally have an impact on the MS-DRG assignment. Figure 6-6 illustrates an example of a complication where the patient developed an infection of a surgical wound. Code 998.59 is assigned to describe the “Postoperative infection”. Codes that describe complications are recorded in FL 67A-Q. A comorbidity is a secondary condition that coexists with the condition for which the patient is seeking health care services. Comorbidities may prolong the patient’s length of stay, usually by 1 day in 75% of cases, which will have an impact on the MS-DRG assignment. An example of comorbidity is a patient presenting with atherosclerosis of an extremity who also has malignant hypertension. Malignant hypertension would be coded, 401.0, as the secondary diagnosis as illustrated in Figure 6-6. Codes that describe comorbidities are recorded in FL 67 A-Q.
The admitting diagnosis is the major most significant reason why the patient is being admitted. For example, if a patient is admitted because he or she is experiencing chest pain and fatigue, the chest pain is the major most significant reason for the admission and therefore is the admitting diagnosis as illustrated in Figure 6-6. The admitting diagnosis is reported in FL 69.
The patient reason for visit is the major most significant reason why the patient is seeking outpatient health care services. Hospital outpatient cases require the patient’s reason for visit to be recorded on the claim form. A code is selected that describes the condition, sign, symptom, illness, injury, disease, or other reason why the patient is receiving outpatient services. The patient’s reason for visit is recorded on outpatient claims in FL 70.
Hospital cases frequently involve the treatment of an injury, poisoning, or other conditions that are caused by an auto accident, falling object, or other external circumstances. These cases require the coder to report an external cause of injury code(s) in addition to the patient’s condition. The ICD-9-CM coding manual contains codes that describe injury, poisoning, and certain other consequences of external causes, as well as external causes of morbidity. Payer guidelines regarding reporting of external causes may vary. External cause of injury codes are recorded in FL 72a-c. It is important for coders to remember that external cause codes are never listed as a principal, admitting, or patient’s reason for visit or first-listed diagnosis on the claim form.
Reimbursement is the term used to describe payment from payers for services provided. Claim forms are submitted to third-party payers, such as insurance companies, Medicare, and other government payers, to obtain reimbursement for services provided. Diagnosis codes are used on the claim form to explain why the services were provided. They are also used to explain the medical necessity for the services. Payers provide reimbursement for services covered by the patient’s plan that are considered medically necessary based on standards of medical care. Therefore, it is critical to ensure that the codes submitted completely describe the patient’s medical condition(s) to establish medically necessity. Figure 6-7 highlights an example of a medical record that contains information required to establish medical necessity. The patient has a lump in her left breast and she has a family history of breast cancer. If the claim was submitted with a diagnosis of pain in the left breast, the payer might not consider the puncture aspiration medically necessary. The submission of diagnosis codes describing the lump and family history of breast cancer provides a clear explanation of why the aspiration was required.
The International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) consists of three sections referred to as Volumes. Volumes I and II are used to code descriptions of the patient’s signs, symptoms, injury, illness, disease, or other reason the patient is seeking health care services. Volume III is used to code descriptions of significant procedures performed during a hospital inpatient stay. Physician and outpatient providers use Volumes I and II. Hospitals and other facilities use Volumes I, II, and III of the ICD-9-CM to report patient conditions and significant procedures performed during the hospital visit. The ICD-9-CM can be purchased with Volume I and II only for physician and outpatient coding or with all three Volumes for use by hospitals and facilities (Figure 6-8).
Volume I is the Tabular List of Diseases generally located in the middle of the ICD-9-CM coding manual. It is listed in the middle of the manual because the coder will reference Volume II, the alphabetic index, first to identify possible codes. Volume I is used to review codes identified in the index (Volume II) for selection of the code that most accurately describes the diagnostic statement in the record. Volume I contents include the Tabular List of Diseases, two supplemental classifications, and appendices, as outlined in Table 6-2.
|1||Infectious and Parasitic Diseases||001–139|
|3||Endocrine, Nutritional, and Metabolic Diseases and Immunity Disorders||240–279|
|4||Diseases of the Blood and Blood-Forming Organs||280–289|
|5||Mental, Behavioral, and Neurodevelopment Disorders||290–319|
|6||Diseases of the Nervous System and Sense Organs||320–389|
|7||Diseases of the Circulatory System||390–459|
|8||Diseases of the Respiratory System||460–519|
|9||Diseases of the Digestive System||520–579|
|10||Diseases of the Genitourinary System||580–629|
|11||Complications of Pregnancy, Childbirth, and the Puerperium||630–679|
|12||Diseases of the Skin and Subcutaneous Tissue||680–709|
|13||Diseases of the Musculoskeletal System and Connective Tissue||710–739|
|15||Certain Conditions Originating in the Perinatal Period||760–779|
|16||Symptoms, Signs, and Ill-Defined Conditions||780–799|
|17||Injury and Poisoning||800–999|
|1.||Factors Influencing Health Status and Contact with Health Services||V01–V89|
|2.||External Causes of Injury and Poisoning||E000–E999|
Only gold members can continue reading. Log In or Register to continue
Premium Wordpress Themes by UFO Themes
You may also need
WordPress theme by UFO themes