Do Objective Measures of Blood Alcohol Concentrations Make More Sense than Self-reports in Emergency Department Studies?

Validity of self-reports of drinking before injury by cause of injury and societal context among emergency department patients

INTRODUCTION AND AIMS

Validity of self-reported alcohol consumption is a topic of continued interest with mixed findings. Validity of self-reports prior to injury is analysed among emergency department (ED) patients by cause of injury, blood alcohol concentration (BAC) and societal context.

DESIGN AND METHODS

Data are on 16 196 injured patients from 23 countries in the International Collaborative Alcohol and Injury Project. The proportion of those reporting drinking within 6 h prior to injury among the 2658 BAC positive patients was analysed by injury cause (traffic, violence, falls, other), BAC level (0.01-0.079 mg%, ≥ 0.08 mg%), detrimental drinking pattern (DDP) and the International Alcohol Policy and Injury Index (IAPII).

RESULTS

Validity averaged 92%, ranging from 85% for drivers to 95% for violence-related injuries. Validity was significantly lower at lower BAC levels for all injuries (P < 0.01) and for violence and falls. Countries with a high DDP and those with lower IAPII scores (less restrictive alcohol policy) also appeared more likely to deny drinking which was significant for DDP for falls (P < 0.01) and for IAPII for passengers/pedestrians (P < 0.05) and violence (P < 0.05). Validity was highest for high IAPII countries, ranging from 92% to 99%.

DISCUSSION AND CONCLUSIONS

Validity of self-report compared to breathalyzer readings at the time of admission to the ED was high, but varied by cause of injury, BAC level, country-level detrimental drinking patterns and the restrictiveness of alcohol control policy. Findings may support the utility or self-reports as an alternative to a quantifiable measure of BAC in the ED setting.

Comparison of different methods assessing alcohol contribution to emergency room visits

INTRODUCTION

The main objective of research was to compare different methods of assessing alcohol's contribution to injuries and medical conditions treated in ER in Poland. Four methods are discussed, including breathalyzer reading, clinical appraisal following Y91 codes of ICD 10, interviewer's observation and self-report.

METHODS

In two Polish sites Warsaw and Sosnowiec probability samples of patients admitted to ER were selected and interviewed face-to-face by trained interviewers. Almost 1.5 thousand patients were interviewed with response rate of 67%. To identify injuries and medical conditions associated with drinking (preceded by alcohol consumption) four methods were used: clinical observations made by nurses trained in applying Y91 codes of ICD-10 (in the Sosnowiec ER only), observations by interviewers who did not receive such a training, breathalyzer readings and patient self-reports of drinking within six hours prior to the event.

RESULTS

A breathalyzer reading identified 4.5% under the influence of alcohol among all patients, and 5.7% among those who were breathalyzed. Clinical assessment in Sosnowiec and interviewers' observations in both cites identified almost the same proportion: 5.1% and 4.7%, respectively and self-reports almost 10%. All four measures for identifying potentially alcohol related ER visits found a total of 11.5% cases among sampled patients.

Studying psychoactive substance use in injured patients: does exclusion of late arriving patients bias the results?

BACKGROUND

Most studies of the prevalence of psychoactive substances in injured emergency department patients have excluded those who arrive more than 6h after injury. This may cause a selection bias. The aim of this study was: (1) to describe the characteristics of patients who arrive more than 6h after injury, compared to patients who arrive sooner (2) to examine whether self-report can add to the assessment of alcohol use when the patient is assessed more than 6h after injury.

METHODS

Blood sample analysis and self-report data were used to assess the prevalence of psychoactive substances in injured patients admitted to an emergency department within 48 h of injury (n=1611). Discriminant function analysis was used to assess group differences.

RESULTS

The patients who arrived more than 6h after injury differed significantly from those who arrived earlier in several respects. They more often screened positive for hypnotics; they were older, they were more likely to have had a fall and they were more often injured at home and at night. Self reported use of alcohol showed good consistency with blood sample screening within 6h of injury and could therefore be used to assess alcohol use more than 6h after injury.

CONCLUSIONS

Patients who arrive more than 6h after injury differ significantly from those who arrive earlier. Future studies on the prevalence of psychoactive substances in emergency departments could expand the inclusion window.

Alcohol and cannabis use as risk factors for injury--a case-crossover analysis in a Swiss hospital emergency department

Background

There is sufficient and consistent evidence that alcohol use is a causal risk factor for injury. For cannabis use, however, there is conflicting evidence; a detrimental dose-response effect of cannabis use on psychomotor and other relevant skills has been found in experimental laboratory studies, while a protective effect of cannabis use has also been found in epidemiological studies.

Methods

Implementation of a case-crossover design study, with a representative sample of injured patients (N = 486; 332 men; 154 women) from the Emergency Department (ED) of the Lausanne University Hospital, which received treatment for different categories of injuries of varying aetiology.

Results

Alcohol use in the six hours prior to injury was associated with a relative risk of 3.00 (C.I.: 1.78, 5.04) compared with no alcohol use, a dose-response relationship also was found. Cannabis use was inversely related to risk of injury (RR: 0.33; C.I.: 0.12, 0.92), also in a dose-response like manner. However, the sample size for people who had used cannabis was small. Simultaneous use of alcohol and cannabis did not show significantly elevated risk.

Conclusion

The most surprising result of our study was the inverse relationship between cannabis use and injury. Possible explanations and underlying mechanisms, such as use in safer environments or more compensatory behavior among cannabis users, were discussed.