A relevant 'Condition onset flag' (COF) shall be assigned to each ICD-10-AM code recorded for an episode of care that complies with Australian Coding Standards (ACS) 0048 Condition onset flag.
Codes should not be re-sequenced in an attempt to list codes with the same COF values together.
Code 1 Condition present on admission to the the episode of care
A condition previously existing or suspected on admission to the current episode of care such as the presenting problem, a co morbidity, or chronic disease.
Includes:
- A condition that has not been documented at the time of admission, but clearly did not develop after admission (e.g. newly diagnosed diabetes mellitus, malignancy and morphology).
- A previously existing condition that is exacerbated during the current episode of care (e.g. atrial fibrillation, unstable angina).
- A condition that is suspected at the time of admission and subsequently confirmed during the current episode of care (e.g. pneumonia, acute myocardial infarction (AMI), stroke, unstable angina).
- A condition impacting on obstetric care arising prior to admission (e.g. venous complications, maternal disproportion).
- For neonates, this also includes the condition(s) in the birth episode arising before the labour and delivery process (e.g. prematurity, birth weight, talipes, clicking hip).
- Disease status or administrative codes not arising during the episode of care (e.g. history of tobacco use, duration of pregnancy, colostomy status).
- Outcome of delivery (Z37) and place of birth (Z38) codes.
Code 2 Condition arose during the episode of care
A condition which arose during the current episode of care and would not have been present or suspected on admission.
Includes:
- A condition resulting from misadventure during surgical or medical care in the current episode of care (e.g. accidental laceration during procedure, foreign body left in cavity, medication infusion error).
- An abnormal reaction to, or later complication of, surgical or medical care arising during the current episode of care (e.g. postprocedural shock, disruption of wound, catheter associated urinary tract infection (UTI)).
- A condition newly arising during the episode of care (e.g. pneumonia, rash, confusion, UTI, hypotension, electrolyte imbalance).
- A condition impacting on obstetric care arising after admission, including complications or unsuccessful interventions of labour and delivery or prenatal/postpartum management (e.g. labour and delivery complicated by fetal heart rate anomalies, postpartum haemorrhage).
- For neonates, this also includes the condition(s) in the birth episode arising during the birth event (i.e. the labour and delivery process) (e.g. respiratory distress, neonatal aspiration, conditions associated with birth trauma, newborn affected by delivery or intrauterine procedures).
- Disease status or administrative codes arising during the episode of care (e.g. cancelled procedure, multi-resistant Staphylococcus aureus (MRSA)).
Code 9 Condition onset unknown/uncertain on admission to the episode of care
A condition where the clinical documentation does not support assignment to code 1 orcCode 2.
Explanatory notes:
When a single ICD-10-AM code describes multiple concepts (i.e. a combination code) and any concept within that code meets the criteria of arising during the episode of care, assign COF 2.
Where multiple conditions/sites are classifiable to a single ICD-10-AM code that meets the criteria for different COF values, assign COF 2; excepting where the condition/site is sequenced as the principal diagnosis and must be assigned COF 1.
The COF value assigned to external cause, place of occurrence and activity codes should match that of the corresponding injury or disease code. Injuries which occur during the episode of care but not on the hospital grounds (e.g. hospital in the home (HITH)) should be assigned COF 2 as 'arising during the episode of care'.
The COF value assigned to morphology codes should match that on the corresponding neoplasm code.
The COF value on Z codes related to the outcome of delivery on the mother's record (Z37), or the place of birth on the baby's record (Z38) should always be assigned COF 1 (present on admission).
The COF value on aetiology and manifestation (dagger and asterisk) codes should be appropriate to each condition and therefore the dagger and asterisk codes may be assigned different COF values.
An episode of care includes all periods when the patient remains admitted and under the responsibility of the health care provider, including periods of authorised leave and HITH. Where diagnoses arising during this period meet the criteria for ACS 0002 Additional diagnoses, clinical coders should apply the COF Guide for use instructions and assign COF 2 if appropriate. Unauthorised leave does not fall under the responsibility of the health care provider and conditions arising during this time should be assigned COF 1.
Where a hospital stay has multiple admitted patient episode 'care type' changes (e.g. acute to rehabilitation), COF assignment should be relevant to each episode of care. A condition arising in an episode should be assigned COF 2. If care for that condition continues in subsequent episodes of care those conditions should be assigned COF 1.