Injury: what should we count

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Injurywhat should we count?

• John Langley
• Megan Davies

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Background

• For public hospital discharges NZ has counted
  anything with an E code for the purposes of
  describing the injury problem!

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All public hospital discharges withE code 1998
(n105,862)

• Non injury diagnosis for the principal diagnosis
  accounts for 36 (n38,434) of all E coded
  discharges.
• Of these 41 (n15,735) did not have injury as
  secondary or subsequent diagnosis.
• Vast majority (80) of 15,735 cases had E
  codes identifying iatrogenic factors (e.g.
  adverse effects of drugs)

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What is in the ICD Injury and Poisoning chapter?

• Fractures, Dislocations, Sprains/strains,
  internal injury, open wounds, injury to blood
  vessels, late effects of injury, superficial
  injury, contusions, crushings, effects of foreign
  bodies, burns, injury to nerves and spinal cord,
  traumatic complications, poisonings, toxic
  effects. (800-994).
• Certain adverse effects not elsewhere classified
  (995).
• Complications of surgical and medical care not
  elsewhere classified (996-999).

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One view of dealing with medical injury

• Conditions in the range 995-999 should be
  excluded from the definition of injury for most
  studies because they have different aetiology and
  means of prevention.

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Response to that strategy

• Neither is sufficient grounds for exclusion.
• Besides which the argument does not stand close
  scrutiny
• aspects of aetiology may be the same! (needle
  injury)
• Prevention strategies may be different but so
  too are they for suicide compared with
  unintentional injury
• Rather the decision should be based on whether
  they meet the theoretical definition of injury.

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Theoretical Definition of Injury

• Damage to the body produced by acute exposure to
  thermal, mechanical, electrical, or chemical
  energy, or the absence of such essentials as heat
  or oxygen.
• Damage due to some chronic low exposures (e.g.
  carpal tunnel syndrome) is also included by some.

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996-999 Complications of surgical and medical
care not elsewhere classified non-injury?

• 996.0 Mechanical complication of cardiac device,
  implant of and graft
• 997.1 Cardiac complications (e.g . Cardiac arrest
  during a procedure)
• 998.0 Postoperative infection
• 999.7 Generalized vaccinia

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996-999 Complications of surgical and medical
care not elsewhere classified injury?

• 997.0 Central nervous system complications (e.g
  anoxic brain damage during procedure)
• 998.2 Accidental puncture or laceration during a
  procedure
• 998.4 Foreign body accidentally left during
  procedure

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• Excluding all medical injuries is the equivalent
  of throwing the baby out with the bathwater

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Significance of medical injuries for estimates of
incidence and determining priorities NZ
experience 1999 hospital inpatients

• Traditional injury (800-994) 40,924 83
• Medical injury (995-999) 8,167 17
• All injury (800-999) 49,091 100

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Hospital Discharge Data

• Availability
• about 40 states
• Health Dept may not have access
• Comparability
• types of hospitals reporting
• numbers of diagnostic fields
• data elements
• E codes
• confidentiality

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Hospital Discharge Data

• Quality
• Completeness of hospitals reporting
• Ability to detect multiple hospitalizations for
  same injury
• Cross-border hospitalizations
• Other out-of-state hospitalizations (eg, in
  winter residents of FL or AZ)

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Hospital Discharge Data

• Quality
• Percentage of injury hospitalizations with
  external cause coding
• hospital
• diagnosis
• demographics
• season
• Accuracy of coding (external cause and nature of
  injury)

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Hospital Discharge Data

• Ad hoc working group
• case definition for injury hospitalization
• calculating percentage of external cause coding
• Injury Surveillance Workgroup 3
• Recommendations for the Use of HDD for Injury
  Surveillance

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Injury Hospitalization

• Hospital
• Non-federal
• Acute-care
• Inpatient facility

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Injury Hospitalization

• Principal diagnosis injury
• Includes
• late effects
• re-admissions
• transfers
• deaths in hospital
• Excludes
• adverse effects of therapeutic drugs and
  medical/surgical care and their late effects

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Injury Hospitalization

• Includes
• 800-909.2, 909.4, 909.9
• 910-994.9
• 995.5-995.59
• 995.80-995.85

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Injury Hospitalization

• Excludes
• lt800
• 909.3, 909.5
• 995.0-995.4, 995.6-995.7, 995.86, 995.89
• 996-999

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Injuries (?) outside the ICD injury and poisoning
chapter

• 717 Internal derangement of knee
• 718 Other derangement of joint
• 724 Other and unspecified disorders of back

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If there is no discernible physical damage to the
body why are we counting the following as
injury?

• Rape ?
• Foreign bodies ?
• Back pain?
• None of these fit a commonly accepted
  theoretical definition of injury.

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Theoretical Definition of Injury

• Damage to the body produced by acute exposure to
  thermal, mechanical, electrical,or chemical
  energy, or the absence of such essentials as heat
  or oxygen.
• Damage due to some chronic low exposures (e.g.
  carpal tunnel syndrome) is also included by some.

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Conclusion

• We need to revisit our theoretical definition of
  injury.
• Having done the above we need to reconsider our
  operational definition of injury (in terms of ICD
  diagnosis codes).
• These issues will become increasingly important
  as we move to intra and inter country comparisons
  of non-fatal injury.

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Injury Prevention Research Unit is supported by