MICROBIOLOGY

Basic coding guidelines apply for both morbidity and mortality coding

1.     Identify the type of statement to be coded and refer to the appropriate section of the alphabetical index (diseases/nature of injury, external causes, drugs & chemical, procedures)

2.     Locate the lead term.  For diseases and injuries this is usually a noun for the pathological condition. However, some conditions expressed as adjectives or eponyms are included in the Index as lead terms.  

The Lead terms describe the patient’s actual condition or disease or an eponyms, not the site or type some useful lead terms include: complication anomaly delivery, labour, puerperal, pregnancy sequelae admission, examination, history of, observation, status

3.     Read and be guided by any note that appears under the lead term

4.     Read any terms enclosed in parentheses after the lead term, as well as any terms indented under the lead term, until all the words in the diagnostic term have been accounted for. 

 

Examples of lead terms and Modifiers

Lead Term         Modifiers

Malaria              Plasmodium falciparum , Vivax                                  (type of condition)

Fracture               Spine (site of the condition)

Gonorrhea        Acute, Chronic (Nature of                                             condition)

Infection           Upper (site) respiratory (system                                   involved)

Otitis                   Acute (stage of condition) media                              (location)

 

Follow carefully any cross-references ("see" and "see also") found in the Index.

6. Refer to the Tabular List to verify the suitability of the code number selected.

7. Be guided by any inclusion or exclusion terms under the selected code or under the chapter, block or category heading.

8. Assign the code.

Rules for Morbidity Coding

Morbidity Coding is the assignment of diagnoses written in a medical record or other source document at the end of an episode of care, to the ICD standard.

an episode of care is a period of admitted patient care between an admission and a discharge or death or series of contacts with health practitioner regarding the same problem or its immediate consequences

Underlying Cause of Death Importance

Why is it important to identify the underlying cause of death?

•           To prevent death, it is necessary to break the chain of events that lead to death, or to effect a cure of the underlying cause.

•           The most effective public health objective is to prevent the precipitating cause.

At the end of episode of care, the treating clinician should record ALL conditions which affected the patient and all procedures and operations provided during the episode of care

The main condition ( Primary Diagnosis) should be uniquely identified

Main condition or primary diagnosis

 

Other or secondary conditions

 

Procedures, operations and interventions

 

External Causes of Injury

 

WHO definition of Primary  and Secondary diagnoses

Primary Diagnosis is…the diagnosis established at the end of the episode of care to be the condition primarily responsible for the patient receiving treatment or being investigated

…that condition that is determined to have been mainly responsible for the episode of health care.

Secondary diagnosis .... either co-exists with the main diagnosis at the time of admission, or appears during the episode of care.

 

Mortality coding has a different set of rules

Main source of mortality coding is the WHO international medical certificate of cause of death

Below is a Kenyan Death Registration Form  ( D1)

 

 

 

Structure of WHO Death Certificate

Importance notes

Entries in Part I should be in a sequence with the underlying cause of death reported on the lowest line

All entries should be recorded legibly without the use of abbreviation

As much detail as possible should be recorded

Rules for mortality coding

General Principle:

When more than one condition is entered on the certificate, select the condition entered alone on the lowest used line of Part I only if it could have given rise to all the conditions entered above it.

Example – General Principle

Example 1:     (a)       Malaria

            Select malaria (B54.9)

Example 2:     (a)       Abscess of lung

                        (b)       Lobar pneumonia

            Select lobar pneumonia (J18.1)

Example 3:     (a)       Hepatic failure

                        (b)       Bile duct obstruction

                        (c)       Carcinoma of head of pancreas

            Select carcinoma of head of pancreas (C25.0)

Example 4:     (a)       Cerebral haemorrhage

                        (b)       Hypertension

                        (c)       Chronic pyelonephritis

                        (d)       Prostatic adenoma

            Select prostatic adenoma (N40)

Rule 1:

            If the General Principle does not apply and there is a reported sequence terminating in the condition first entered on the certificate, select the originating cause of this sequence. If there is more than one sequence terminating in the condition mentioned first, select the originating cause of the first-mentioned sequence.

Example – Rule 1

(a) Bronchopneumonia

(b) Cerebral infarction and hypertensive heart disease

-        the physician certified that there are two reported sequences terminating in the condition first entered on the certificate;

-        certifier has broken the rule by giving two conditions therefore the General Principle does not apply.

-        The originating cause of the first-mentioned sequence is selected.

•        Rule 1 is used to select cerebral infarction (I63.9)

 

 

Rule 2:

If there is no reported sequence terminating in the condition first entered on the certificate, select the first-mentioned condition

Example of Rule 2

1.  (a) Rheumatic and atherosclerotic heart disease

The General Principle and Rule 1 do not apply, why?

Select rheumatic heart disease (I09,9). There is no reported sequence, both conditions are on the same line

2.     (a)           Pernicious anaemia and gangrene of foot

Atherosclerosis

Select pernicious anaemia (D51.0). There is no reported sequence terminating in the first entered condition.

3.    (a)            Fibrocystic disease of the pancreas

Bronchitis and bronchiectasis

Select fibrocystic disease of the pancreas (E84.9). There is no reported sequence.

Rule 3:

If the condition selected by the General Principle or by Rule l or Rule 2 is obviously a direct consequence of another reported condition, whether in Part I or Part II, select this primary condition.

Examples of Rule 3

   I        Kaposi's sarcoma

                        II          AIDS

Select HIV disease resulting in Kaposi's sarcoma (B21.0)  

I.       Tuberculosis

HIV disease Select HIV disease resulting in mycobacterial infection (B20.5)