This study was specifically concerned with exploring the phenomenon of choking (foreign body obstructions) in adults who are potentially more at risk of choking than the general population due to the presence of or
predisposition to swallowing and eating problems. The data sample therefore needed to capture choking fatalities related to foreign body obstructions (as
opposed to choking through other causes such as violence or trauma) and the particular population group of interest.
Initially, in order to capture the most comprehensive sample and one that would ultimately come to provide theoretical sufficiency, the parameters of date range and location (available in the search settings of the NCIS
database) were arbitrarily set at 2000-2010, along with all Australian states and territories.
Identifying choking (foreign body obstructions) cases
To identify foreign body obstruction cases, on the advice of NCIS staff an electronic search of the NCIS data base was performed using the following available search parameters:
1) Date range 2000-2010
2) All states (included Australian territories) 3) Age > 18years
4) Mechanism: Threat to breathing - Mechanical Threat to Breathing - Obstruction of Airway by Inhaled Object/Substance
This search generated over 900 cases.
Identifying adults particularly at-risk of choking
The population of interest was adults who were clinically considered more at risk of choking than the general population. An increased risk of choking has been established in adults of advanced age (due to the presence or
predisposition to dysphagia caused by normal ageing) and/or those with medical conditions associated with dysphagia (Cleary & Hopper, 2010; Dolkas et al., 2007; Ney et al., 2009; Sayre, 2005); the predisposition to or identified presence of dysphagia being the common feature of both groups. Advanced age (70 years or over) and/or relevant medical condition therefore were the primary criteria used to identify an ‘at-risk adult’. Relevant medical
conditions were considered to be those with a known association34 with
swallowing and/or eating problems35 such as motor neurone disease, stroke,
and intellectual disability (Cichero & Murdoch, 2006).
There was no key search parameter that could be entered into the data base to extract the relevant cases for this study. The case reports for each of the choking deaths in the data search above (n>900 cases) were therefore individually read to determine relevance. There were five sources of information on the data base for each case:
1. Identification Panel.
(this panel outlines basic demographic information such as name, age, place of residence, but does not include medical information)
2. Police Report 3. Autopsy Report 4. Toxicology Report
5. Coroner’s Finding (included inquest reports)
Each case was read to identify age and medical history. Those 70 and over were quickly identified using the identification panel. Relevant medical history however could appear exclusively in one of the four primary sources of
information (as noted, the case identification panel did not include medical information) or be repeated across several of the sources. The Police Report was the first source read for each case. If medical history was not indicated in this source, then subsequent case reports were read to determine the presence or otherwise of a medical condition relevant to dysphagia.
Not all cases included a documented medical history. There were however, indicators in some case reports of relevance for inclusion in the study despite the absence of specific medical history information. In such reports the
person was listed as residing in a form of medically assisted-care setting
34 Swallowing and/or eating problems is listed as a symptom of the disease or its treatment, the
condition is reported in the dysphagia literature, or the condition is represented on the clinical case load of adult acute or community public service speech pathologists.
35 Eating problems in this study were defined as eating behaviours such as gorging, eating too fast,
such as a mental health facility or dementia unit, which indicated the
likelihood of a relevant medical condition. In other cases the deceased was reported to have had swallowing problems or previous choking events prior to death.
The selection criteria for cases (the sample) in this study therefore became the following:
1. All cases where the deceased had an injury, illness or condition associated with the possibility of swallowing or disturbed eating behaviours, such as acquired brain injury, Parkinson’s disease, cerebral palsy, or mental illness.
2. All cases where the deceased was 70 years or over (and not included under the first criterion).
3. All cases where swallowing or disturbed eating behaviours or previous choking events had been identified prior to death (may or may not have been included in the above criteria).
Challenges to case selection
All cases on the data base had an identification panel, however not all cases had reports attached. Reasons for this included: ‘Not performed’ (e.g.
autopsy or toxicology); ‘Not electronically available’; and ‘Case dispensed no formal finding’ (some reports may have been present). Some cases only had a police or a coroner’s finding report which could consist of only a few lines of information. The absence of reports or the brevity of some meant there may have been cases relevant to this study which could not be identified as such. Another challenge to case selection was the criteria used for study inclusion. The criterion of medical condition may have led to cases being included which did not meet the intended underlying focus on the ‘at-risk adult’. Some medical conditions such as stroke or head injury may be generally associated with dysphagia, but depending on the site of the brain injury may not actually predispose or cause swallowing dysfunction. Such distinction is not possible given the degree of medical history collected for most coroners’
investigations. Some cases therefore may have been included in the study sample where technically the deceased could not have been considered as potentially ‘at-risk’ prior to fatally choking. This was a limitation of the study.
The final sample
After reading all foreign body obstruction cases, 256 cases met the study criteria of the deceased being an at-risk adult. Those cases which did not meet the criteria included choking due to self-harm, drug or alcohol overdoses, violence, and choking ‘games’. Many of the over 900 cases
originally identified were deaths due to drug or alcohol overdoses (choking on vomit) and cases of self-harm, rather than choking on food. If the death appeared to be due to non-food obstructions but the case met the study’s criteria it was included, as the person was already vulnerable to choking because of a possible swallowing problem, regardless of additional vulnerabilities created such as excessive drug or alcohol intake and associated consequences.
Representing the data: Conventions
The primary data sources of this study were police, forensic pathology, inquest, and findings reports which are written as part of a coronial
investigation. Excerpts from these reports will be used to represent the data throughout this study to illustrate particular points. When excerpts are used they will be followed by brackets inclosing the study case number and the type of report such as (002 Police report). Coroners’ reports include a large amount of potentially identifying data such as the names of those involved (deceased, family members, staff, investigating police, presiding coroner, forensic pathologist) and dates, addresses, name of facilities and the state in which the death occurred.
Once relevant cases were identified, all potentially identifying data indicated above were removed. This information has been replaced with pseudonyms and/or general designators such as deceased, spouse, sibling, doctor, and personal carer. This approach is designed to protect privacy and
confidentiality, and aid readability while maintaining the integrity of the meaning of the excerpt. In addition, where descriptions of events may have elements that could make them more easily identifiable even with names excluded, gender or other elements may have been altered to further protect privacy but maintain contextual integrity; for example ‘Huntington’s’ disease may be replaced with ‘neurodegenerative’ disease.
As the findings are being presented stylistically in a narrative format with coronial excerpts embedded, some additional conventions will be used to help readability. The researcher will use square brackets in excerpts [...] to denote information which has been inserted to assist the reader, such as that which clarifies a technical term or provides contextual clarity. Also to aid the reader, occasionally the tense of excerpts may be altered or misspelt words corrected to enhance the flow of the narrative.