Poisons admissions in Edinburgh 1981-2001: agent trends and predictors of hospital readmissions

Acute Poisoning Readmissions to an Emergency Department of a Tertiary Hospital: Evaluation through an Active Toxicovigilance Program

The aim of this study is to investigate hospital readmissions during 1 year after acute poisoning cases (APC), analyze the temporal behavior of early readmissions (ER) (in the month after the index episode) and predict possible ER. A descriptive analysis of the patients with APC assisted between 2011 and 2016 in the Emergency Department of Hospital La Paz is presented, and various methods of inferential statistics were applied and confirmed by Bayesian analysis in order to evaluate factors associated with total and early readmissions. Out of the 4693 cases of APC included, 968 (20.6%) presented, at least one readmission and 476 (10.1%) of them were ER. The mean age of APC with readmission was 41 years (12.7 SD), 78.9% had previous psychiatric pathology and 44.7% had a clinical history of alcohol addiction. Accidental poisoning has been a protective factor for readmission (OR 0.50; 0.26–0.96). Type of toxin (“drug of abuse” OR 8.88; 1.17–67.25), history of addiction (OR 1.93; 1.18–3.10) and psychiatric history (OR 3.30; 2.53–4.30) are risk factors for readmissions during the first year. Women showed three or more readmissions in a year. The results of the study allow for identification of the predictors for the different numbers of readmissions in the year after the index APC, as well as for ERs.

The performance of COBRA, a decision rule to predict the need for intensive care interventions in intentional drug overdose

BACKGROUND

COBRA was developed as a decision rule to predict which patients visiting the emergency department (ED) following intentional drug overdose will not require intensive care unit (ICU) interventions. COBRA uses parameters from five vital systems (cardiac conduction, oxygenation, blood pressure, respiration, and awareness) that are readily available in the ED. COBRA recommends against ICU admission when all these parameters are normal.

OBJECTIVE

The primary aim of this study was to determine the negative predictive value (NPV) of COBRA in predicting ICU interventions. Secondary outcomes were the sensitivity, specificity and positive predictive value (PPV), and the observation time required for a reliable prediction.

DESIGN

Observational cohort study.

SETTINGS AND PARTICIPANTS

Patients with a reported intentional overdose with drugs having potential acute effects on neurological, circulatory or ventilatory function were included, and data necessary to complete the decision rule was collected. The attending physician in the ED made the actual admission decision, on the basis of clinical judgement. COBRA was measured 0, 3 and 6 h after arrival at the ED.

OUTCOME MEASURES

Need for ICU interventions (treatment of convulsion; defibrillation; mechanical or noninvasive ventilation; intravenous administration of vasopressive agents, antiarrhythmics, atropine, calcium, magnesium or sedation; continuous hemofiltration or administration of antagonist/antidote and fluid resuscitation).

MAIN RESULTS

Of 230 new cases (144 unique patients), 59 were immediately referred to the psychiatric services and/or sent home by the attending physician, 27 went to a regular ward, and 144 were admitted to the ICU. Of these 144 cases, 40 required one or more ICU interventions. By the time the first parameters were collected, the NPV of COBRA was 95.6%. After 3 h of observation, NPV was 100%, while sensitivity, specificity and PPV were 100, 61.1 and 35.1%, respectively. None of these values improved by prolonging the observation time to 6 h.

CONCLUSION

In patients with a reported intentional overdose with drugs having potential acute effects on neurological, circulatory or ventilatory function, the COBRA decision rule showed good performances in predicting the need for intensive care interventions, with a NPV of 100% after 3 h of observation.

Self-poisoning as a cause of admission in a medical intensive care unit and a question of misuse of prescription medications

BACKGROUND

Self-poisoning accounts for between 3 and 17% of intensive care unit (ICU) admissions.

OBJECTIVES

To display the misused substances, intention, and outcome of patients admitted to the ICU due to self-poisoning.

METHODS

A retrospective review of ICU admissions using an electronic patient database was performed.

RESULTS

A total of 149 patients were admitted, accounting for 4.6% of ICU admissions. Self-poisoning with self-harm was more frequent than without self-harm intent (62.4% vs. 37.6%). 64.4% of ingested substances were misused prescribed drugs. Females used antipsychotics (X² = 15, p< 0.05) and benzodiazepines (X² =11.52, p< 0.05), and males ingested antipsychotics (X² = 12, p< 0.05) with a self-harm intent. Antipsychotics were always used with a self-harm intent. Illicit drugs (X² =9.14, p< 0.05) and ethanol (X² =7.34, p< 0.05) were mostly used without self-harm intent. 102 patients (68.5%) continued treatment in a psychiatric clinic, more often women (X² (1,N = 145)=7.94, p< 0.005). The readmission rate was low. Mortality was 2.6%.

CONCLUSION

Self-poisoning is an infrequent cause of ICU admission. Prescribed psychotropic medications, including benzodiazepines, antipsychotics, and antidepressants were the most frequently misused substances. Psychiatric consultation before the ICU discharge and subsequent psychiatric treatment might lower the repetition and readmission rate.

Factors associated with rapidly repeated acute poisoning by substances of abuse: a prospective observational cohort study

Objective

We have previously found that 9% of patients treated for acute poisoning by substances of abuse in a primary care emergency outpatient setting presented with a new poisoning within a week. We now identify factors associated with rapidly repeated acute poisoning by substances of abuse.

Results

In 169/1952 (9%) cases of acute poisoning by substances of abuse included consecutively from October 2011 through September 2012 at a primary care emergency outpatient clinic in Oslo, Norway, the patient re-presented within a week with a new poisoning. Homeless patients were more likely to re-present, adjusted odds ratio (AOR) 2.0 (95% confidence interval (CI) 1.3–3.2, p = 0.003), as were self-discharging patients, AOR 1.7 (95% CI 1.2–2.4, p = 0.007), and patients with an opioid as main toxic agent, AOR 1.5 (95% CI 1.0–2.3, p = 0.028). There was no statistically significant association between rapid re-presentation and severe mental illness or suicidal intention.

Long-term mortality after poisoning with antipsychotics

INTRODUCTION

The objective of this study was to investigate the long-term mortality and cause of death after deliberate self-poisoning with antipsychotics. Furthermore, we investigated the risk of repeated self-poisoning after a first episode of poisoning with antipsychotics.

METHODS

We identified patients with antipsychotic poisoning from the Danish Poison Information Centre Database and correlated their personal identification number with four Danish national registries related to health aspects.

RESULTS

From August 2006 to December 2013 we identified 2289 patients poisoned with antipsychotic agents. The average age of the patients was 35.6 years (SD 14.3) and 68.5% were women. Eleven patients died during the first 30 days, and at the end of follow-up in March 2014, 150 patients were deceased, leading to a mortality rate of 2.1 per 100 person-years and a standardized mortality ratio of 9.0. The most common causes of death were poisoning (29%) and violent suicide (18%) - however half of the patients died from natural reasons. 643 patients (28%) repeated the poisoning once or more.

CONCLUSIONS

Poisoning with antipsychotics was associated with an increased risk of death. Most of these deaths were preventable, and this highlights the need for secondary prophylaxis following a suicide attempt.

Follow-up of young patients after acute poisoning by substances of abuse: a comparative cohort study at an emergency outpatient clinic

BACKGROUND

Young patients with acute poisoning by substances of abuse have increased mortality rates in the long term. In Oslo, Norway, most of these patients are treated at the Oslo Accident and Emergency Outpatient Clinic. The majority were discharged without follow-up. In 2010, the clinic implemented an intervention program for patients under the age of 23 presenting with acute poisoning by substances of abuse. The intervention was a brief motivational interview with a social worker before discharge, followed by a telephone consultation. Patients in need of further follow-up were identified and referred. Our objective was to study short-term effects of the intervention program on referrals to follow-up and repetition rates of acute poisoning.

METHODS

Comparative cohorts were derived from studies of acute poisoning at the Oslo Accident and Emergency Outpatient Clinic in 2003, 2008 and 2012. Two age groups of patients presenting with acute poisoning by substances of abuse were included: 16-22 years and 23-27 years. Patients in the pre-intervention cohorts of 2003 and 2008 were compared with patients of the same age in the post-intervention cohort of 2012. Repetition rates were estimated using survival analysis. In total, 1323 patients were included; 422 in the younger pre-intervention group, 366 in the younger post-intervention group, 288 in the older pre-intervention group, and 247 in the older post-intervention group. Overall, the major toxic agents were ethanol 823/1323 (62 %) and opioids 215/1323 (16 %). 719/1323 (54 %) patients were male.

RESULTS

In the younger groups referrals to follow-up increased from 86/317 (27 %) to 156/366 (43 %) (p < 0.001) after the implementation of the program. Among the older patients, who were not included in the program, there was no significant change in referrals. There was no change in the repetition rate of acute poisoning in either age group. The program established contact with 225/366 (61 %) of the eligible patients.

CONCLUSION

More patients were referred to follow-up after the intervention. We expect this to have a beneficial effect on their substance use and reduce excess morbidity and mortality in the long term. There was no change in the repetition rate of poisoning.

Outcomes and Costs of Poisoned Patients Admitted to an Adult Emergency Department of a Spanish Tertiary Hospital: Evaluation through a Toxicovigilance Program

Abstract

Toxicovigilance is the active process of identifying and evaluating the toxic risks existing in a community, and evaluating the measures taken to reduce or eliminate them.

Objective

Through a validated toxicovigilance program (SAT-HULP) we examined the characteristics of acute poisoning cases (APC) attended in the Emergency Department (ED) of La Paz Hospital (Madrid, Spain) and assessed their economic impact on the health system.

Material and Methods

The active poisoning surveillance system performs a daily search for cases in the hospital´s computerized case records. Found cases are entered into a database for recording of type of poisoning episode, reasons for exposure, causative agent, signs and symptoms and treatment. We carried out a cross-sectional epidemiological study with analytical projection, based on an impact study on cost per survivor. The data for the costs attributable to cases of APC observed at HULP (outpatients and inpatients) was obtained from the based on the information provided by the diagnosis-related groups (DRG) through the corresponding hospital discharge reports (available through SAT-HULP).

Results

During the first 30 month of SAT-HULP operation we found a total of 3,195 APC, a cumulative incidence rate of 1.75% of patients attended in the ED. The mean (SD) patient age was 40.9 (17.8) years and 51.2% were men. Drug abuse accounted for 47.5% of the cases. Suicide attempt was the second most frequent category (38.1%) and other causes accounted for 14.5% of APC. The total cost of hospital care for our hospital rose to €1,825,263.24 (approximately €730,105.30/year) resulting in a permanent occupation of 4 beds/year.

Conclusions

SAT-HULP constitutes a validated toxicovigilance tool, which continuously integrates available data in real-time and helps health services manage APC data flexibly, including the consumption of resources from the health system.

A prospective cohort study of trends in self-poisoning, Newcastle, Australia, 1987-2012: plus ça change, plus c'est la même chose

OBJECTIVE

To examine inhospital mortality and morbidity associated with self-poisoning with different drug classes over an extended period.

DESIGN, SETTING AND PARTICIPANTS

A prospective cohort study over 26 years (1987-2012) with limited follow-up of patients presenting consecutively to a primary and tertiary referral toxicology centre covering Newcastle, Lake Macquarie and Port Stephens, Australia.

MAIN OUTCOME MEASURES

Hospital length of stay, types of drugs ingested, intensive care unit (ICU) admission, requirement for ventilation, inhospital deaths and rates of antidepressant drug use in Australia.

RESULTS

Over the study period, there were 17 266 admissions of patients poisoned by 34 342 substances (16 723 drugs available only on prescription). The median length of stay was 16 hours, 12.2% of patients (2101/17 266) were admitted to an ICU, 7.4% (1281/17 266) were ventilated and 78 (0.45%) died in hospital. Patient demographics, social and psychiatric factors remained stable over the 26-year period, but case fatality decreased (from 0.77% [15/1955] to 0.17% [7/4060]) as did ICU admissions (19.2% [376/1955] to 6.9% [280/4060]), ventilation (13.7% [268/1955] to 4.8% [193/4060]) and LOS. The most frequently ingested substances were alcohol, benzodiazepines, paracetamol, antidepressants and antipsychotics. There was a substantial fall in some highly toxic drugs (tricyclic antidepressants, barbiturates, conventional antipsychotics and theophylline), but increases in less toxic selective serotonin reuptake inhibitors, serotonin-noradrenaline reuptake inhibitors and paracetamol. A greater than sixfold increase in community antidepressant use was accompanied by only minor changes in overall and antidepressant self-poisoning rates.

CONCLUSION

Over two decades, there were decreases in poisonings by many highly toxic drugs which were associated with substantial reductions in morbidity and inhospital deaths. Despite massive increases in the number of antidepressant prescriptions, neither rates of self-harm nor the proportion of antidepressant poisonings increased markedly.

Self-poisoning with medications in adolescents: a national register study of hospital admissions and readmissions

OBJECTIVE

To examine characteristics of hospital admissions and risk factors associated with rehospitalization for self-poisoning with medications in adolescents aged 10-19 years.

METHOD

This study used data from the Norwegian Patient Register from 2008 to 2011. The main outcome was hospital readmission within the observation period. A complementary log-log regression model was used to assess the effect of characteristics at index hospital admission on readmission.

RESULTS

Of 1497 patients, 76.4% were females and 89.8% were aged 15-19 years. At their first hospital admission, about one third received a secondary psychiatric diagnosis. Females (47.5%) were registered with an E-code for intentional self-harm more often than males (33.7%), and females were more often than males discharged to further treatment (27.8% vs. 21.5%). As many as 18.4% were rehospitalized for self-poisoning by medications. Significant predictors for hospital readmission were female sex [hazard ratio (HR) = 2.4, 95% confidence interval (CI) 1.7-3.6], discharge to further treatment (HR = 2.3, 95% CI 1.8-2.9) and psychiatric secondary diagnoses (HR = 1.5, 95% CI 1.2-1.9).

CONCLUSION

This national study demonstrated significant sex differences in adolescents treated in hospital for self-poisoning with medications. Psychiatric secondary diagnoses had a strong predictive effect on readmission, which indicates the importance of psychiatric/psychosocial assessment of adolescents who are admitted to hospital for self-poisoning with medications.

Characteristics, procedural differences, and costs of inpatients with drug poisoning in acute care hospitals in Japan

OBJECTIVES

This study aimed to describe the clinical and procedural characteristics of drug poisoning, to examine procedural differences between drug poisoning repeaters and non-repeaters, and to estimate the costs of drug poisoning.

METHODS

A retrospective cohort study of a nationally representative sample of 6585 inpatients with drug poisoning was conducted, using the administrative database of the Diagnosis Procedure Combination/Per-Diem Payment System in 2008.

RESULTS

Although only 3% of patients required surgery and 65% were discharged from the hospitals within 3 days, greater than 30% were admitted to tertiary emergency care (i.e., high-level emergency care) centers that provide care to severely ill and trauma patients who require intensive care. Only 30% of patients received psychiatric consultation during hospitalization. In addition, repeaters were less likely to be admitted to hospitals by ambulance (67% vs. 76%) and more likely to be discharged within 3 days (77% vs. 65%) than non-repeaters. The annual economic burden of drug poisoning in Japan was $66 million (¥7.7 billion), with the population aged 20-39 years accounting for 50% of these costs.

CONCLUSION

This study highlights the need for optimally allocating resources and improving prevention strategies.

Detailed analyses of self-poisoning episodes presenting to a large regional teaching hospital in the UK

AIMS

The primary aim of this paper is to provide comprehensive contemporaneous data on the demographics, patterns of presentation and management of all episodes of deliberate self-poisoning presenting to a large regional teaching hospital over a 12 month period.

METHODS

We undertook detailed, retrospective analyses using information from electronic patient records and local patient-tracking, pathology and administrative databases. Statistical analyses were performed using Chi-squared tests, anova and two-tailed t-tests (Graphpad Prism).

RESULTS

One thousand five hundred and ninety-eight episodes of deliberate self-poisoning presented over the year. Demographic data and information on the month, day and time of admission are provided. 70.7% presented to the emergency department (ED) within 4 h of ingestion. 76.3% of patients had only one episode in an extended 29 month follow-up period. A mean of 1.72 drugs were taken per episode with just over half of all episodes involving a single drug only. Paracetamol and ibuprofen were the two most commonly ingested drugs involved in 42.5% and 17.3% of all overdoses respectively. 56.3% of patients taking paracetamol reported ingesting over 8 g (one over the counter packet). Detailed mapping of the patients' pathway through the hospital allowed an estimation of the hospital cost of caring for this patient group at pound 1.6 million pounds per year.

CONCLUSIONS

We present comprehensive and contemporary data on presentations to hospital resulting from deliberate self-poisoning. We include demographic information, presentation patterns, drugs used, a detailed analysis of episodes involving paracetamol and an estimate of the financial burden to hospitals of overdose presentations.

Limiting paracetamol pack size: has it worked in the UK?

INTRODUCTION

Paracetamol poisoning is a major health problem worldwide. Limitation of pack size is an approach increasingly advocated to reduce rates of suicide and serious self-harm from this agent. The United Kingdom adopted such a policy in 1998, restricting non-pharmacy sales to 8 g and pharmacy to pack sizes of 16 g.

METHODS

A literature review was conducted and commentary written on the impact of the change in the United Kingdom on a variety of indices of paracetamol overdose.

RESULTS

Potential markers of effect identified included paracetamol sales, poisons information data, laboratory results, liver unit referrals, and hospital activity and mortality data. Initial reports suggested effects associated with the legislation, but longer term suicide trend analysis has not confirmed these early findings, which were confounded by population trends in self-harm.

CONCLUSION

Paracetamol pack size limitation as applied in the United Kingdom has not reduced paracetamol-related death. Reasons postulated for this failure include patient avoidance of the legislation's intentions, patient confusion, and ineffectiveness of the regulations as conceived and implemented.

Repetition of acute poisoning in Oslo: 1-year prospective study

BACKGROUND

The repetition of acute poisoning occurs frequently. The intention may change between episodes and many poisonings are treated outside the hospital setting. Few studies have taken this into account.

AIMS

To quantify the repetition frequency regardless of the level of health care or the intention behind the poisoning, and to identify possible risk factors for repetition.

METHOD

A prospective multicentre study of all acute poisonings in Oslo treated in hospital, at an out-patient clinic or by the ambulance service. Repetition was estimated using Kaplan-Meier calculations, and predictive factors were identified using Cox regression analysis.

RESULTS

The estimated 1-year repetition rate was 30% (95% CI 24-35). Independent predictors of repetition were middle age (30-49 years), poisoning with opiates or sedatives, unemployment or living on social welfare, a previous suicide attempt, and a history of psychiatric treatment. Intention was not a significant predictor.

CONCLUSIONS

Repetition of acute poisoning is high, irrespective of the level of healthcare and the intention behind the poisoning.

Patterns of antiepileptic drug overdose differ between men and women: admissions to the Edinburgh Poisons Unit, 2000-2007

BACKGROUND AND AIMS

Antiepileptic drugs are increasingly used in patients with psychiatric disorders who are at increased risk of self-harm. This might increase the likelihood that these agents are used as a means of overdose. This study was designed to examine the rate of occurrence of antiepileptic drug overdose between 2000 and 2007.

METHODS

A retrospective observational study examined patterns of antiepileptic drug overdose in patients admitted to the Edinburgh Poisons Unit, and compared prescription data for the corresponding region. Data were compared using chi-square trend tests.

RESULTS

There were 18 010 admissions to the Toxicology Unit, and 613 patients ingested at least one antiepileptic drug (3.4%). The most frequently implicated were carbamazepine, sodium valproate, phenytoin and lamotrigine, which corresponded with those most commonly prescribed. Women were more likely to ingest lamotrigine than men (P < 0.0001), and less likely to ingest sodium valproate (P = 0.0234). Patients that ingested antiepileptic drugs were more likely to be admitted to hospital for >1 day (22% vs. 8%, P < 0.0001) and need transfer to a psychiatric facility (14% vs. 7%, P < 0.0001).

CONCLUSIONS

Patients that ingested antiepileptic drugs required more intensive medical and psychiatric intervention compared to ingestion of other agents. Significant gender differences were noted in the specific antiepileptic drug ingested. Further work is required to establish whether this discrepancy may be explained by gender-based prescribing practices.