Rajakumar.M,
Manager-Medical Records,
Aravind Eye Care System.

The number of people working in the health care field has increased tremendously. This fact, coupled with an increase in the number and kinds of health care specialists, makes it imperative that there is clear communication about a patients condition. Use of standardized terminology to describe clinical progress and treatment procedures is one of the means for ensuring that all people involved in patient care have a common understanding of the patients disease. Numerous attempts have been made over the years to compile accurate descriptions and identifications of all known diseases. Prior to the nineteenth century, results of such attempts produced some rudimentary classification systems.

Classification of diseases and operations is one of the most important functions of the medical records department. A well-organized department selects one of the best-suited International Classification Systems to code and index diseases and operations for the collection of morbidity and mortality information. A classification of diseases is a system of grouping together morbid entities according to some established criteria.

What is coding?
It is the translating of narrative descriptions of diseases, injuries and procedures into numeric codes. The coding process involves assigning numbers to disease and procedural terms. The principal source of coded information is the medical record. The face sheet lists final diagnoses and operations and is completed by the attending physician. A code number for each disease and operation is recorded on the face sheet by a coder.

Why do we need to code?
Coding is done in order to group conditions and procedures that are similar for statistical tabulation. Medical and health statistics are generally used to:

• Plan appropriate health services
• Classify patterns of disease in a health care facility
• Forecast health needs of communities, regions and nations
• Study epidemiology (incidence rates of diseases, etc)
• Standardize reporting systems for easy assimilation
• Provide teaching material for medical education
• Evaluate health care with appropriate measures.

In order to develop the best possible health care delivery system with preventive, curative, primitive and rehabilitative components, it is necessary to have comprehensive information or morbidity and mortality. Therefore there is a need for the disease classification standard to be acceptable throughout the globe. Hence the development of ICD came into existence.

Code numbers:
The code numbers that follow the terms refer to categories and subcategories under which the terms should be classified. If the code has only three characters, it can be assumed that the category has not been subdivided. In most instances where the category has been subdivided, the code number in the index will give the fourth character. A dash in the fourth position (003.-) means that the category has been subdivided and that the fourth character can be found by referring to the tabular list. In listing inclusions and exclusion terms in the tabular list, the ICD employs some special conventions relating to the use of the abbreviations NOS, NEC use of parentheses, square brackets, colons, braces, the word and in titles. These need to be clearly understood both by coders, and by anyone wishing to interpret statistics based on the ICD.

Introduction to Ophthalmology ICD-9-CM:
This ophthalmology coding book is divided into three sections. The first section contains the introduction, guidelines for use and the outline of the ICD-9-CM, showing the major categories of diseases and where they may be found in the tabular columns. The second section is an Alphabetical Index of specific diseases entries. The third section is the most important for proper coding, the tabular list. This section will guide you for proper and accurate coding. While searching for a specific code, it is always easy to refer an alphabetical index. Here most of the diseases are cross referenced in several ways making it easier. One can refer to the tabular list for more precise guidelines of coding. When one becomes more familiar with the coding process one may find that one refers to the alphabetical index less often. However, coding will be more accurate if one refers to the tabular list since it has more precise guidelines.

Introduction of ICD- 10:
Volume 1 of the ICD contains the classification itself. It indicates the categories into which diagnoses are to be allocated, facilitating their sorting and counting for statistical purposes. It also provides those using statistics with a definition of the content of the categories, subcategories and tabulation list items they may find included in statistical tables. Although it is theoretically possible for a coder to arrive at the correct code by the use of volume 1 alone, this would be time-consuming and could lead to errors in assignment. An alphabetical index as a guide to the classification is contained in volume 3. The introduction to the index provides important information about its relationship with volume 1.

Volume 2 of the Tenth Revision of the International Statistical Classification of Diseases and Related Health Problems contains guidelines for recording and coding, together with much new material on practical aspects of the classifications use, as well as an outline of the historical background to the classification. Volume 2 is presented as a separate volume for ease of handling when reference needs to be made at the same time to the classification (Volume 1) and the instructions for its use. Detailed instructions on the use of the Alphabetical Index are contained in the introduction to Volume 3.

On the other hand, Volume 3 of the International Statistical Classification of Diseases and Related Health Problems is an alphabetical index to the Tabular List of Volume 1. Although the index reflects the provisions of the Tabular List with regard to the notes varying the assignment of a diagnostic term when it is reported with other conditions, or under particular circumstances (e.g., certain conditions complicating pregnancy), it is not possible to express all such variations in the index terms. Volume 1 should therefore be regarded as the primary coding tool. The Alphabetical Index is however, an essential adjunct to the tabular list, since it contains a great number of diagnostic terms that do not appear in Volume 1. Therefore the two volumes must be used together.

Classification of Diseases:
All medical files of patients treated in both the outpatient and the inpatient department must be coded for disease classification by the medical record department according to the latest International Classification of Diseases. A classification system for grouping by like diagnoses must be used. Various classification systems have been used, but one in common use today is the International Classification of Diseases adapted for use in the United States (ICD-9-CM) 2003 coding. This classification is an adaptation of the World Health Organizations clinical modification, 9th revision of International Classification of Diseases and is designed to serve various statistical purposes including hospital indexing.

Classification of Operations:
All medical files of patients treated in both the outpatient and inpatient departments must be coded for operation classification by the medical record department according to the latest International Classification of Operations. Usually ICP-9 is in use today to code the medical records for the minor and major procedures done.

Manual Index:
An important function of the medical record department is the compilation of patient care data from medical records. This means that certain information about patient care was extracted from medical records and hand posted on ledger sheets or cards. Indexing manually means that disease and operation code numbers are entered on each appropriate disease or operative index cards. The disease conditions for which patients were treated were coded and then posted on a set of index cards, which comprised the disease index. A third set of cards contained the names of all physicians attached to a health facility and listed the names of every patient those physicians treated. The majority of facility personnel, while maintained and containing valuable information, often knew these three indexes. While there are many manually maintained indexes still in existence, the trend is the increasing computerization of this activity.

A manual disease and operation index can be maintained on lined 5-inch-by-8-inch cards in a vertical or visible filing cabinet or on 8 1/2-inch-by-11-inch lined paper in a three-ring, loose-leaf binder. The minimum data for each diagnosis is posted on the appropriate card or sheet labeled for that diagnosis. When a patient has more than one diagnosis, the diagnoses are cross referenced. For example, if the diagnosis on a discharged patients record were astigmatism and cataract, each diagnosis would be posted on its card or sheet and each would show the other condition as an associated disease.

Automated indexes:
Many health care facilities have incorporated or are considering the inclusion of the disease and operation indexes in their data processing system. Abstracts should be designed to correspond to the procedure for retrieval of information from the patients health records. The indexing is usually done on the computer to reduce workload and to increase speed in computing data. The disease and operation indexes are the most expensive indexes to maintain in the department. The indexing clerk must not only be a capable individual, but also extremely accurate in making the entries. Indexing systems may be effectively designed for computerized entry into a data processing system. Programs can be written to extract information and routine printouts; however, the needs of the persons using the stored information should be considered of prime importance. Related patient information on printouts should be grouped together for easy retrieval.

Disease and Operation Index:
A disease index lists diseases and conditions according to the classification system or code numbers assigned by medical record department personnel. The operation index is comprised of a listing of surgical and procedural code numbers. A physician or a medical staff committee might use the disease and operation indexes to retrieve medical records for the following purposes:

1. To review previous cases of a given disease in order to provide insight into the management of current patients health problems.
2. To test theories and compare data on certain diseases and/or treatments in order to conduct research and prepare scientific papers.
3. To procure data on the utilization of hospital facilities and to establish a hospitals need for new equipment, beds, staff, etc., in various departments.
4. To evaluate the quality of care in the hospital.
5. To conduct epidemiological and infection control studies on the work environment.
6. To accumulate risk management data, such as the incidence of medical and surgical complications.

Disease and operation indexes should be modified to meet the needs of the institutions they serve. The indexes basically need to contain only two items of information the medical records number and the disease or operative codes. The indexes should provide sufficient detail to comply with required medical and statistical reports and requests. Anticipated special requests for information may be easily incorporated into indexing procedures and promptly retrieved at the appropriate time.

Physicians Index:
The physician index provides a record of the patients he has treated for every medical staff member. Entries on physicians index cards usually list the name and medical records number of the patient, but may include other data such as the hospital service which treated the patient, and audit or utilization review proceedings. It may also indicate those cases for which a physician served as surgeon or consultant, the end results of hospitalization, and any other information which might be desirable. In addition to physicians use of the indexes, numerous requests for patient care data are received from hospital administrators and authorized personnel, planning agencies, educational programs, and health care agencies and organizations.

Filing Equipment for Manual Indexes:
Small indexes may be conveniently filed in visible filing equipment where the titles of all cards are visible because the edge of one card projects the width of one line beyond the edge of the previous card. The cards may be inserted in pockets which have a celluloid edge, hinged to card holders, or hung from rods. Such files enable the indexing clerk to quickly locate a desired index card. Errors made while filing cards are minimal because all card titles are readily visible. In vertical indexes, cards stand upright in the file. It is necessary to place guides throughout the file to aid the clerk in finding a desired index card. Special tags which facilitate rapid card location may be attached to those index cards which are used frequently. Because vertical files required less space than do visible files, they are more suitable for large indexes.

Indexing Control:
There must be some method for ensuring that every record is indexed. If the indexing is done before the records are sent to the incomplete file, a complete days disposed or discharged record may be put on the indexing persons desk at one time. Indexing may be done after the physician has completed the record and it has been checked for completion by medical record personnel. Indexing at that time is the last step before the record is sent to the permanent file. Incorrect coding, as well as incorrect indexing, results in a loss of research material. Ideally one or two persons can be appointed exclusively to do all the indexing as this fixes responsibility for the work and should result in a more consistent index.

Quality Control:
Diagnosis and operation code are not simply used to provide data for physicians research. Once an appropriate classification system has been chosen and implemented in a health care facility, it is extremely important that continuous internal quality control measures are used to ensure the accuracy of the collected information. Because of the vast usage of recorded information, it is essential that coded diagnoses and operations are accurate and readily retrievable. The codes used should describe the patients condition and treatment as definitively as the classification system will allow. Classification of diseases and operations should be accurate in three areas individual codes should correctly classify patient information according to the classification system used. The collection of code numbers for each patient should reflect the totality of his medical condition at the time of treatment. Finally, the code numbers must be assigned in proper sequence to reflect the principal reason for the episode of care and any contributing secondary diagnoses and operations.