Acknowledgement of “no fault” medical injury: review of patients' hospital records in New Zealand

Investigations of the epidemiology of adverse events have advanced the safety of patients in hospital.¹ These studies, however, were done in tort jurisdictions, where the fear of litigation may have inhibited frank and open discussion.² New Zealand abolished tort liability in 1972, instead providing an administrative system of compensation without the need to prove fault.³ We analysed data on adverse events in hospitals in New Zealand and the extent to which medical injury is acknowledged in patient records.

Participants, methods, and results

We took data on patient admissions from a representative sample of 13 from the 20 public hospitals with 100 or more beds. The survey population comprised all patients admitted in 1998 (excluding day patients, psychiatric patients, and patients attending just for rehabilitation). We reviewed the records of sampled patients retrospectively in two stages. To qualify as an adverse event, an incident had to have occurred or been detected by a healthcare professional during the sampled admission.¹

We defined an adverse event as an unintended injury resulting in disability that was likely to have been caused by healthcare management rather than the underlying disease. We defined an acknowledgement as an annotation in a patient's record indicating or suggesting that healthcare management had caused the medical injury.

Of the 6579 admitted patients who were screened according to set criteria (see bmj.com), the records of 4119 were reviewed by doctors using a structured protocol. Doctors judged 883 patients as having unintended injuries and resulting disabilities, and they assessed whether healthcare management had caused these injuries. Reviewers considered whether any note in the medical records indicated or suggested that healthcare management had caused the injuries.

After adjusting for sample design, reviewers classified 672/717 (94%) patients with records acknowledging injury as having had an adverse event compared with 81/166 (47%) patients whose records did not have such acknowledgement (relative risk 2.01; 95% confidence interval 1.75 to 2.32). We did similar calculations for subsets of adverse events that occurred in hospital (table). We estimated relative risks using the Mantel-Haenszel method and adjusted for the sample design (stratified cluster). Relative risks were greater for higher impact incidents and for “non-preventable” events.

For almost 672/753 (90%) adverse events, an annotation in the patient's record acknowledged medical injury. More than 148/181 (80%) adverse events involving systems failure in hospital were annotated.

Comment

Annotations in patients' records were a good predictor that a medical injury had been caused by healthcare management, regardless of clinical context. Fear of litigation may be an obstacle to reporting error—particularly for high impact, preventable, and systemic events. Our results show that the level of acknowledgement of medical injury in patients' records can be remarkably high in a no fault jurisdiction and strongly predictive of such occurences.

Doctors in many countries are discouraged from reporting medical errors,⁴ yet litigation in tort jurisdictions is becoming more common.⁵ In no fault jurisictions, the relatively high level of annotation in patient records that we found could provide a basis for more vigorous error reporting.

Table.

Acknowledgement of medical injury in patients' hospital records in New Zealand (n=883^*)

Adverse events in hospital	Injury annotated (n=717)			No injury annotated (n=166)		Relative risk (95% CI)
	No	%†		No	%†
All (n=604)	536/581	92		68/153	42	2.19 (1.84 to 2.60)
Hospital type:
Tertiary (n=296)	268/298	90		28/76	35	2.54 (1.87 to 3.43)
Secondary (n=308)	268/283	95		40/77	49	1.92 (1.57 to 2.35)
Clinical risk‡:
High (n=400)	353/379	93		47/91	50	1.89 (1.47 to 2.42)
Low (n=204)	183/202	90		21/62	32	2.80 (1.85 to 4.23)
Patient impact§¶:
Permanent disability or death (n=83)	73/118	62		10/95	9	6.64 (3.97 to 11.07)
Temporary disability lasting <1 year (n=499)	446/491	91		53/138	37	2.48 (2.03 to 3.02)
Preventability§:
Evidence (n=366)	313/358	87		53/138	36	2.44 (1.94 to 3.05)
No evidence (n=238)	223/268	83		15/100	15	5.69 (3.32 to 9.77)
Systems failure§:
Evidence of (n=181)	148/193	76		33/118	26	2.93 (2.12 to 4.03)
No evidence of (n=423)	388/433	89		35/120	27	3.28 (2.56 to 4.20)

^*Includes 753 cases judged to be adverse events, of which 604 occurred in hospital. 

^†Adjusted for sample design. 

^‡Major diagnostic categories (based on the Australian Diagnostic Related Group classification system 3.1) were classified into two groups according to the percentage of admissions associated with an adverse event in hospital (>9.2% and ⩽9.2% where 9.2% was the mean). 

^§Adverse events were compared to the 130 non-adverse events, except for the hospital type and clinical risk subsets, in which admissions from the same group were used. 

^¶Extent of disability could not be determined from the medical records of 22 patients.