- Email: [email protected]
A simple guide to burn epidemiology
ISBI/WHO: Simple guides
217
A simple guide to burn epidemiology Prepared
by Elizabeth McLaughlin
(ScD), San Francisco, California,
Burn epidemiology Epidemiology is a science which deals with the incidence, distribution and control of injuries and diseases in a defined population. Bum data are the ‘raw material’ of bums epidemiology.
Uses of bum data Bum data are useful to: Define the bum problem in a population. Determine the most common ways that people are burned. Evaluate the effectiveness of medical care for bum patients. Identify which bum hazards should be targeted by bum prevention strategies. Evaluate the success of bum prevention programmes. Examine the economic impact of bum injuries and bum treatment.
Sources of burn data The sources of bum data severity of the bum injury:
vary,
depending
upon
the
Collect information from hospitals and For burn deaths local, regional, or national vital statistics registries. Many people die immediately of fire and bum injuries and do not receive medical care. Collect information from hospitals. For serious bums Decide whether to collect data only on bum patients admitted to the hospital, or on all patients seen at the hospital. If there are several hospitals treating bum patients from the defined population, collect data from all these hospitals. Referral patterns may distort the true profile of bums in that population. Collect information from health For less severe bums clinics, doctors’ offices, visiting nurses or any other medical treatment service. A good sampling plan will make this task easier. For bums of all levels of severity occurring in a community Collect information through a community in face-to-face or telephone survey, asking residents interviews to recall circumstances of bum injuries suffered by family members. Questions about bum injuries could be added to a larger multipurpose community survey. Contact the For burns associated with building fires local fire service for information about fires in which people were killed or injured. Remember, this is not a good source
USA, Chair, ISBI Prevention
for clothing ignition chemical bums.
bums,
Committee
scalds, contact,
electrical
or
Standard coding of burn injury data Most countries use the World Health Organization’s International Classification of Disease (ICD) Codes for coding data on hospital discharge records, although there are other coding schemes. For example, the Nordic countries use a coding scheme called NOMESCO. The ICD system contains two sets of codes for bum data. The first set classifies what type of fire or bum injury was sustained:
CODE
TYPE OF BURN
940-949 986-987 692.71 910-919
Bum injuries Smoke inhalation Sunburn Superficial injuries (friction bums are among these codes)
The second set of codes are the ICD E-codes (External Cause of Injury), which classify the causes of bums. These are four-digit codes, with the fourth digit often capturing important bum information:
CODE
CAUSE OF BURN
E890-899
Bums caused by fire and flames Accident caused by explosive material (includes fireworks and explosive gases; not all injuries coded here are bums) Accident caused by hot substance or object, caustic material and steam Accident caused by electric current (bums or electrocution) Exposure to radiation Suicide (by bums or scalds) Homicide and assault (965.6, 967, 968.0, .3 relate to bums) Undetermined if accidentally or purposely inflicted War
E923
E924 E925 E926 E958.1, .2 E965-968 E988.1, .2 E990,996
Nature of data needed to answer research questions How big is our bum problem? Determine the number of people who have been burned. Do not ignore bum deaths, especially those who die before coming to the hospital. Counts of non-fatal bums are made easier in areas where computerized hospital discharge records are coded using the International Classification of
Burns: Vol. 21, No. 3, 1995
218
Disease Codes or another standard coding scheme. Count the number of patients with a bum injury diagnosis coded using ‘type of bum’ codes. How are our people getting burned? Determine the number of people burned by specific causes of bums, such as clothing ignition or scalds. Collect information which will permit patients to be classified using ‘cause of bum’ codes. Accurate, useful coding depends upon accurate, useful information in the medical record. This includes details about the circumstances of the burning, ignition sources and other product involvement, where the event happened and the activities of the people involved, and demographic information about the patient. This often requires an interview with the patient, a family member or someone present at the bum episode. Make sure that this information is written in the medical record, coded and, whenever possible, entered into computerized hospital discharge records. How can we prevent burns? Analyse data describing the common causes of injuries in the population, to identify high risk groups as young children, and high-risk activities, such as preparation. See the companion A Simple Guide to Prevention (see pp. 226-229) for strategies to prevent injuries.
bum such meal Burn bum
How can we evaluate the success of our prevention programmes? The precise nature of the data required depends upon the prevention programme and the research design of the evalutation.
Information about larger populations It is important to know certain characteristics of the defined population, whether this be a village, a region or a country. Important characteristics are: the number of people in the population and the age distribution of these people. If your country collects and publishes census data, these provide an excellent source of information to use to describe risk factors for bums in your population. This symbol is used to signal an example from the literature to illustrate a point. Socioeconomic Factors and the Incidence of Hospitalized Burn injuries in New England Counties, USA’ is a study which used census data to identify bum risk factors. The authors found several demographic and socioeconomic variables to be highly associated with the incidence of hospitalized bum injuries. For example, bum rates decrease as the population’s income and education levels increase. Bum rates are higher in populations living in older housing.
Burn rates Bum epidemiology uses rates of bum injury or deaths. A rate is calculated by dividing the number of bum injuries sustained during a specified time period, by the number of people in a population during that same period. It is expressed, for example, as ‘bums per 10000 population per year’. One must use bum rates to compare the bum problem in communities or countries with different sized
populations. A densely populated community may have many more bums but a much lower bum rate than a sparsely populated region. A lower bum rate signifies a lesser bum problem. It is important to know the age distribution of the defined population because bum risk is age related. A population with a lower median age will have higher rates even if its adults have an equal or slightly lower risk than a population with a higher median age. An Analysis of 1704 Burn Injuries in Hong Kong Children2 is a study which calculated bum rates for a subset of an entire population. Seven major regional hospitals treat 90 per cent of Hong Kong’s total population. These hospitals’ medical records for a 12-month period were reviewed for information about bum patients aged 0-14 years. Census data provided the denominators for the rate calculations. The authors calculated that the bum risk of a child in Hong Kong in the O-4 year age group was 2.45 per 1000 children per year.
Usefulness of burn data from a single hospital If only one hospital treats patients with serious bums in a defined population, and if one is interested only in serious bums, then the vital statistics registry and this hospital are the two appropriate data sources for fatal and serious bum injuries, respectively, for that population. If the hospital is one among many serving a single population, one cannot draw any conclusions about the population’s bum problem by studying only one hospital. However, even without collaboration with other local hospitals, it can be valuable to analyse bum data from a single hospital. Individual hospitals can provide useful information about a specific circumstance which causes bums, and can provide ‘cases’ for a ‘case-control’ study. One cannot, however, draw conclusions about the population’s bum problem. Scald Accidents During Water Aerosol Inhalation in Infants’ is a study from a single hospital in Kuwait which examined scalds to infants. The authors found a pattern for scalds involving parents who were trying to treat a child’s respiratory infection. The problem was unstable containers for the hot water. The authors recommended the use of a humidifier that is relatively cheap, safe and easy to use.
Some useful research designs The collection of bum data is not an end in itself. It should lead to answers to the questions posed by bum epidemiologists, which include: How severe is the bum injury problem in a defined population? What are the environmental and behavioural risk factors associated with bum injuries? How effective is a certain bum prevention programme? Below are the broad outlines of four research designs which may be helpful in planning and implementing bum prevention programmes and their evaluation. Experimental and Quasi-experimental Designs for Research4 and Designing Clinical Research: An Epidemiological Approach5 are two among many ‘research methods’ textbooks which can assist the reader in conducting research at the local or national level.
219
ISBI/WHO: Simple guides
Non-experimental Purpose To determine dimensions defined population
descriptive study of a serious bum problem
in a
Tasks 1. Define the population of interest, determine numbers and age distribution, if possible. 2. Decide on a time period. Include at least one year, since in most locations, bum injuries have seasonal variations. 3. Decide on level of bum severity. Include all deaths and people hospitalized for a bum injury, and maybe those treated and released from hospital or clinic. 4. Identify all hospitals treating bum patients in the Request permission to review defined population. medical records or request hospital staff’s help to provide data. bum form to collect all available 5. Use a standardized information. Record as much information as is available on the circumstances surrounding the bum episode. The ISBI Bum Registry computer software is a useful tool for collecting and recording bum data. See the accompanying Simple Guide fo Burn Registry. 6. Prepare report to include rates: a. death rates ([no. deaths/no. in population] x 1000 000), expressed as deaths per 1000 000 persons b. injury rates ([no. injuries/no. in population] x lOOOOOO), expressed as injuries per 1000000 persons. Calculate rates for the following categories: i. age groups ii. gender iii. type of bum (flame, scald, other) iv. severity (depth and extent of bum). 7. Identify the most common circumstances and/or products causing injury (e.g. pressure stoves, clothing ignition). programme to address these prob8. Plan a prevention lems. A literature review may reveal which strategies have been effective. An Epidemiological Analysis of Deaths Caused by Burns in Osaka, Japan6 indicated that the bum death rate in Osaka was 2.6 deaths per 100000 population. Housefires and suicidal electric bums were the most common causes of bum deaths. Seventythree per cent of the fatally injured people died without receiving medical treatment. This study illustrates the importance of going to death records, rather than relying solely on medical records to define the bum problem. The literature includes more population-based descriptive studies of bum deaths than of bum injuries, because $eaah data have been more available than non-fatal injury a . An Analytical Study of Burns in Kashmir’ reports on data collected from the only hospital in Kashmir Valley with facilities for plastic surgery, 0 and thus may treat all the serious bums in the valley. It found that clothing ignition by a ‘Kangri’, a portable unguarded heater, is the major bum hazard for children.
Pre-experimental pretest-post-test
design: one group design
Purpose To document gramme.
associated
change
with a prevention
pro-
Cautions There is no control for natural time trends, societal forces and factors other than the intervention which influence bum rates. Tasks Conduct the descriptive study (seep. 219) to determine the bum problem in a defined population. Determine rates for those types of bum injuries and those age groups expected to be affected by the programme. Design or adapt a bum prevention programme which addresses a significant bum problem. Repeat the descriptive study and compare bum-type and age-specific rates before and after the intervention. Note If the prevention intervention has already been instituted, as it often is with safety standards or regulations, the descriptive studies of burns before and after implementation are retrospective and may be conducted simultaneously. Bums are relatively rare occurrences and are known to have yearly fluctuations. For this reason, it is well to collect data for several years before and after intervention. Prevention of Burns and Scalds in a Developed Counfys used this design to evaluate the efficacy of the recall of defective extension cords on a popular brand of vacuum cleaner in Denmark. In the years prior to recall, there were 23 electrical bums of the mouth in young children. In the 5 years after recall, there were only three. Control of Firework Injuries in India: Experiences from a Five Year Sfudy9 used this design to evaluate the efficacy of a programme in India to prevent firework injures and to promote cool water as the proper first aid treatment for bums. The evaluation incorporated data from both hospitals and community surveys. It found that a television campaign to encourage cool water was effective, although little effect was noted in reducing firework injuries. Bum data and product analysis had revealed that the design of ‘conical fountain’ fireworks and amount of explosives in ‘bangers’ and ‘rockets’ increased the risk posed by fireworks. Prevention of Children’s burns: Legislation and Fabric Flammabilify’” used this design to evaluate the children’s sleepwear flammability standard in New Zealand. The study found a reduction of all children’s clothing ignition bums, not solely of sleepwear. This suggests that there were factors in addition to the sleepwear flammability standard which influenced bum rates.
220
Bums: Vol. 21, No. 3, 1995
Quasi-experimental design: non-equivalent control group design Purpose To measure gramme.
the effectiveness
of a bum prevention
pro-
Tasks Conduct the descriptive study (see p. 219) to determine the bum problem in two communities. These communities should be comparable in size, age distribution and socioeconomic variables. Select a bum prevention programme, proven to be effective in other locations, which addresses a bum problem shared by both defined communities. Randomly select one community as experimental and one as control. Conduct the prevention programme in the experimental community. Repeat the descriptive study in both populations and compare bum-type and age-specific rates. A successful programme would be indicated by significantly lower bum rates in the experimental community with rates essentially unchanged in the control community. Project Bum Prevention: Outcome and Implicafionsll and The Incidence and Severity of Bum Injuries Following Project Bum Prevention’2 used this design to evaluate the efficacy of a comprehensive bum prevention education programme in Boston. The 5-year study collected bum data in two metropolitan areas, conducted the programme in one area, and then continued to collect data in both areas during the prograrnme and for one year after it. No reduction in bum injuries was found in either the experimental or the control community.
Experimental design: a case-control study Purpose To measure the effectiveness of a bum prevention programme; for example, whether a new inexpensive kerosene stove, recently introduced into a community, has reduced the likelihood that someone will be burned. Tasks Identify ‘cases’, that is, patients treated for bum injuries caused by stoves. Interview the patient or family member to determine the type of stove used by the patient. Determine fuel source, whether or not stove is the ‘new design’. Select appropriate ‘control’ for each case. This is the most difficult task of a case-control study, to find persons comparable to the case in all things except the type of stove used in the home. It is well to find multiple controls for each case, drawing from different categories. For instance, a hospital ‘control’ could be a person admitted to the hospital the same day for an illness rather than an injury, who is the same gender, same socioeconomic status and in the same age group as the bum patient. A neighbourhood ‘control’ could be a person living on the same road, within a certain number of houses, who is the same gender, same socioeconomic
status and in the same age group as the bum patient. 4. Interview each ‘control’ to determine the type of stove used. Determine fuel source, whether or not stove is the ‘new design’. 5. Analyse data using simple 2 x 2 table, categorizing subjects along two axes: positive or negative for bum injuries associated with stoves, and positive or negative for exposure to ‘new stove’. Success would be achieved if those using the new stove were significantly less likely to be in the bum category. There are no published case-control studies of a bum prevention intervention. However, Aefiology of Bum Injuries Among Children Aged C-4 years: Resulfs of a Case-confrol StudyI used this design to identify risk factors for bums in young children in the Netherlands. The authors found increased bum risk among children with other than Dutch ethnicity, and children living in very small housing units, and in homes using gas for cooking.
References 1 Locke JA, Rossignol
2
3 4
5
6
7 8 9
10
11
12
13
AM, Burke JF. Socioeconomic factors and the incidence of hospitalized bum injuries in New England Counties, USA. Bums 1990; 16: 273-277. Cheng JCY, Leung KS, Lam ZC, Leung PC. An analysis of 1704 bum injuries in Hong Kong children. Bums 1990; 16: 182-184. Ebrahim MKH, Bang RL, Lari ARA. Scald accidents during water aerosol inhalation in infants. Bums 1990; 16: 291-293. Campbell DT, Stanley JC. Experimenfal and Quasi-erperimental Designs for Research. Chicago: Rand McNally College Publishing Company, 1966. Hulley SB, Cummings SR (eds). Designing Clinical Research: An Epidemiological Approach. Baltimore: Williams & Wilkins, 1988. Yoshioka T, Ohashi Y, Sugimoto H, Sawada Y, Kobayashi H, Sugimoto. Epidemiological analysis of deaths caused by bums in Osaka, Japan. Btlms 1982; 8: 414-422. Mall CN, Misgar MS, Khan M, Singh S. Analytical study of bums in Kashmir. Bums 1983; 9: 180-183. Sorensen B. Prevention of bums and scalds in a developed country. ] Trauma 1976; 16: 249-258. Mohan D, Varghese M. Confrol of Firework Injuries in India: Experiences from a Five Year Sftldy. Paper presented at the First World Conference on Accident and Injury Prevention, Stockholm, Sweden, 17-21, September, 1989. McLaughlin E, Langley JD, Laing RM. Prevention of children’s bums: legislation and fabric flammability. NZ Med ] 1986; 99: 804-807. McLaughlin E, Vince CJ, Lee AM, Crawford JD. Project bum prevention: outcome and implications. Am ] Public Health 1982; 72: 241-247. MacKay AM, Rothman KJ. The incidence and severity of bum injuries following Project Bum Prevention. Am ] Public Health 1982; 72: 248-252. van Rijn OJL, Bouter LM, Kester ADM et al. Aetiology of bum injuries among children aged 0-4~: results of a case-control study. Bums 1991; 17: 213-219.
217
A simple guide to burn epidemiology Prepared
by Elizabeth McLaughlin
(ScD), San Francisco, California,
Burn epidemiology Epidemiology is a science which deals with the incidence, distribution and control of injuries and diseases in a defined population. Bum data are the ‘raw material’ of bums epidemiology.
Uses of bum data Bum data are useful to: Define the bum problem in a population. Determine the most common ways that people are burned. Evaluate the effectiveness of medical care for bum patients. Identify which bum hazards should be targeted by bum prevention strategies. Evaluate the success of bum prevention programmes. Examine the economic impact of bum injuries and bum treatment.
Sources of burn data The sources of bum data severity of the bum injury:
vary,
depending
upon
the
Collect information from hospitals and For burn deaths local, regional, or national vital statistics registries. Many people die immediately of fire and bum injuries and do not receive medical care. Collect information from hospitals. For serious bums Decide whether to collect data only on bum patients admitted to the hospital, or on all patients seen at the hospital. If there are several hospitals treating bum patients from the defined population, collect data from all these hospitals. Referral patterns may distort the true profile of bums in that population. Collect information from health For less severe bums clinics, doctors’ offices, visiting nurses or any other medical treatment service. A good sampling plan will make this task easier. For bums of all levels of severity occurring in a community Collect information through a community in face-to-face or telephone survey, asking residents interviews to recall circumstances of bum injuries suffered by family members. Questions about bum injuries could be added to a larger multipurpose community survey. Contact the For burns associated with building fires local fire service for information about fires in which people were killed or injured. Remember, this is not a good source
USA, Chair, ISBI Prevention
for clothing ignition chemical bums.
bums,
Committee
scalds, contact,
electrical
or
Standard coding of burn injury data Most countries use the World Health Organization’s International Classification of Disease (ICD) Codes for coding data on hospital discharge records, although there are other coding schemes. For example, the Nordic countries use a coding scheme called NOMESCO. The ICD system contains two sets of codes for bum data. The first set classifies what type of fire or bum injury was sustained:
CODE
TYPE OF BURN
940-949 986-987 692.71 910-919
Bum injuries Smoke inhalation Sunburn Superficial injuries (friction bums are among these codes)
The second set of codes are the ICD E-codes (External Cause of Injury), which classify the causes of bums. These are four-digit codes, with the fourth digit often capturing important bum information:
CODE
CAUSE OF BURN
E890-899
Bums caused by fire and flames Accident caused by explosive material (includes fireworks and explosive gases; not all injuries coded here are bums) Accident caused by hot substance or object, caustic material and steam Accident caused by electric current (bums or electrocution) Exposure to radiation Suicide (by bums or scalds) Homicide and assault (965.6, 967, 968.0, .3 relate to bums) Undetermined if accidentally or purposely inflicted War
E923
E924 E925 E926 E958.1, .2 E965-968 E988.1, .2 E990,996
Nature of data needed to answer research questions How big is our bum problem? Determine the number of people who have been burned. Do not ignore bum deaths, especially those who die before coming to the hospital. Counts of non-fatal bums are made easier in areas where computerized hospital discharge records are coded using the International Classification of
Burns: Vol. 21, No. 3, 1995
218
Disease Codes or another standard coding scheme. Count the number of patients with a bum injury diagnosis coded using ‘type of bum’ codes. How are our people getting burned? Determine the number of people burned by specific causes of bums, such as clothing ignition or scalds. Collect information which will permit patients to be classified using ‘cause of bum’ codes. Accurate, useful coding depends upon accurate, useful information in the medical record. This includes details about the circumstances of the burning, ignition sources and other product involvement, where the event happened and the activities of the people involved, and demographic information about the patient. This often requires an interview with the patient, a family member or someone present at the bum episode. Make sure that this information is written in the medical record, coded and, whenever possible, entered into computerized hospital discharge records. How can we prevent burns? Analyse data describing the common causes of injuries in the population, to identify high risk groups as young children, and high-risk activities, such as preparation. See the companion A Simple Guide to Prevention (see pp. 226-229) for strategies to prevent injuries.
bum such meal Burn bum
How can we evaluate the success of our prevention programmes? The precise nature of the data required depends upon the prevention programme and the research design of the evalutation.
Information about larger populations It is important to know certain characteristics of the defined population, whether this be a village, a region or a country. Important characteristics are: the number of people in the population and the age distribution of these people. If your country collects and publishes census data, these provide an excellent source of information to use to describe risk factors for bums in your population. This symbol is used to signal an example from the literature to illustrate a point. Socioeconomic Factors and the Incidence of Hospitalized Burn injuries in New England Counties, USA’ is a study which used census data to identify bum risk factors. The authors found several demographic and socioeconomic variables to be highly associated with the incidence of hospitalized bum injuries. For example, bum rates decrease as the population’s income and education levels increase. Bum rates are higher in populations living in older housing.
Burn rates Bum epidemiology uses rates of bum injury or deaths. A rate is calculated by dividing the number of bum injuries sustained during a specified time period, by the number of people in a population during that same period. It is expressed, for example, as ‘bums per 10000 population per year’. One must use bum rates to compare the bum problem in communities or countries with different sized
populations. A densely populated community may have many more bums but a much lower bum rate than a sparsely populated region. A lower bum rate signifies a lesser bum problem. It is important to know the age distribution of the defined population because bum risk is age related. A population with a lower median age will have higher rates even if its adults have an equal or slightly lower risk than a population with a higher median age. An Analysis of 1704 Burn Injuries in Hong Kong Children2 is a study which calculated bum rates for a subset of an entire population. Seven major regional hospitals treat 90 per cent of Hong Kong’s total population. These hospitals’ medical records for a 12-month period were reviewed for information about bum patients aged 0-14 years. Census data provided the denominators for the rate calculations. The authors calculated that the bum risk of a child in Hong Kong in the O-4 year age group was 2.45 per 1000 children per year.
Usefulness of burn data from a single hospital If only one hospital treats patients with serious bums in a defined population, and if one is interested only in serious bums, then the vital statistics registry and this hospital are the two appropriate data sources for fatal and serious bum injuries, respectively, for that population. If the hospital is one among many serving a single population, one cannot draw any conclusions about the population’s bum problem by studying only one hospital. However, even without collaboration with other local hospitals, it can be valuable to analyse bum data from a single hospital. Individual hospitals can provide useful information about a specific circumstance which causes bums, and can provide ‘cases’ for a ‘case-control’ study. One cannot, however, draw conclusions about the population’s bum problem. Scald Accidents During Water Aerosol Inhalation in Infants’ is a study from a single hospital in Kuwait which examined scalds to infants. The authors found a pattern for scalds involving parents who were trying to treat a child’s respiratory infection. The problem was unstable containers for the hot water. The authors recommended the use of a humidifier that is relatively cheap, safe and easy to use.
Some useful research designs The collection of bum data is not an end in itself. It should lead to answers to the questions posed by bum epidemiologists, which include: How severe is the bum injury problem in a defined population? What are the environmental and behavioural risk factors associated with bum injuries? How effective is a certain bum prevention programme? Below are the broad outlines of four research designs which may be helpful in planning and implementing bum prevention programmes and their evaluation. Experimental and Quasi-experimental Designs for Research4 and Designing Clinical Research: An Epidemiological Approach5 are two among many ‘research methods’ textbooks which can assist the reader in conducting research at the local or national level.
219
ISBI/WHO: Simple guides
Non-experimental Purpose To determine dimensions defined population
descriptive study of a serious bum problem
in a
Tasks 1. Define the population of interest, determine numbers and age distribution, if possible. 2. Decide on a time period. Include at least one year, since in most locations, bum injuries have seasonal variations. 3. Decide on level of bum severity. Include all deaths and people hospitalized for a bum injury, and maybe those treated and released from hospital or clinic. 4. Identify all hospitals treating bum patients in the Request permission to review defined population. medical records or request hospital staff’s help to provide data. bum form to collect all available 5. Use a standardized information. Record as much information as is available on the circumstances surrounding the bum episode. The ISBI Bum Registry computer software is a useful tool for collecting and recording bum data. See the accompanying Simple Guide fo Burn Registry. 6. Prepare report to include rates: a. death rates ([no. deaths/no. in population] x 1000 000), expressed as deaths per 1000 000 persons b. injury rates ([no. injuries/no. in population] x lOOOOOO), expressed as injuries per 1000000 persons. Calculate rates for the following categories: i. age groups ii. gender iii. type of bum (flame, scald, other) iv. severity (depth and extent of bum). 7. Identify the most common circumstances and/or products causing injury (e.g. pressure stoves, clothing ignition). programme to address these prob8. Plan a prevention lems. A literature review may reveal which strategies have been effective. An Epidemiological Analysis of Deaths Caused by Burns in Osaka, Japan6 indicated that the bum death rate in Osaka was 2.6 deaths per 100000 population. Housefires and suicidal electric bums were the most common causes of bum deaths. Seventythree per cent of the fatally injured people died without receiving medical treatment. This study illustrates the importance of going to death records, rather than relying solely on medical records to define the bum problem. The literature includes more population-based descriptive studies of bum deaths than of bum injuries, because $eaah data have been more available than non-fatal injury a . An Analytical Study of Burns in Kashmir’ reports on data collected from the only hospital in Kashmir Valley with facilities for plastic surgery, 0 and thus may treat all the serious bums in the valley. It found that clothing ignition by a ‘Kangri’, a portable unguarded heater, is the major bum hazard for children.
Pre-experimental pretest-post-test
design: one group design
Purpose To document gramme.
associated
change
with a prevention
pro-
Cautions There is no control for natural time trends, societal forces and factors other than the intervention which influence bum rates. Tasks Conduct the descriptive study (seep. 219) to determine the bum problem in a defined population. Determine rates for those types of bum injuries and those age groups expected to be affected by the programme. Design or adapt a bum prevention programme which addresses a significant bum problem. Repeat the descriptive study and compare bum-type and age-specific rates before and after the intervention. Note If the prevention intervention has already been instituted, as it often is with safety standards or regulations, the descriptive studies of burns before and after implementation are retrospective and may be conducted simultaneously. Bums are relatively rare occurrences and are known to have yearly fluctuations. For this reason, it is well to collect data for several years before and after intervention. Prevention of Burns and Scalds in a Developed Counfys used this design to evaluate the efficacy of the recall of defective extension cords on a popular brand of vacuum cleaner in Denmark. In the years prior to recall, there were 23 electrical bums of the mouth in young children. In the 5 years after recall, there were only three. Control of Firework Injuries in India: Experiences from a Five Year Sfudy9 used this design to evaluate the efficacy of a programme in India to prevent firework injures and to promote cool water as the proper first aid treatment for bums. The evaluation incorporated data from both hospitals and community surveys. It found that a television campaign to encourage cool water was effective, although little effect was noted in reducing firework injuries. Bum data and product analysis had revealed that the design of ‘conical fountain’ fireworks and amount of explosives in ‘bangers’ and ‘rockets’ increased the risk posed by fireworks. Prevention of Children’s burns: Legislation and Fabric Flammabilify’” used this design to evaluate the children’s sleepwear flammability standard in New Zealand. The study found a reduction of all children’s clothing ignition bums, not solely of sleepwear. This suggests that there were factors in addition to the sleepwear flammability standard which influenced bum rates.
220
Bums: Vol. 21, No. 3, 1995
Quasi-experimental design: non-equivalent control group design Purpose To measure gramme.
the effectiveness
of a bum prevention
pro-
Tasks Conduct the descriptive study (see p. 219) to determine the bum problem in two communities. These communities should be comparable in size, age distribution and socioeconomic variables. Select a bum prevention programme, proven to be effective in other locations, which addresses a bum problem shared by both defined communities. Randomly select one community as experimental and one as control. Conduct the prevention programme in the experimental community. Repeat the descriptive study in both populations and compare bum-type and age-specific rates. A successful programme would be indicated by significantly lower bum rates in the experimental community with rates essentially unchanged in the control community. Project Bum Prevention: Outcome and Implicafionsll and The Incidence and Severity of Bum Injuries Following Project Bum Prevention’2 used this design to evaluate the efficacy of a comprehensive bum prevention education programme in Boston. The 5-year study collected bum data in two metropolitan areas, conducted the programme in one area, and then continued to collect data in both areas during the prograrnme and for one year after it. No reduction in bum injuries was found in either the experimental or the control community.
Experimental design: a case-control study Purpose To measure the effectiveness of a bum prevention programme; for example, whether a new inexpensive kerosene stove, recently introduced into a community, has reduced the likelihood that someone will be burned. Tasks Identify ‘cases’, that is, patients treated for bum injuries caused by stoves. Interview the patient or family member to determine the type of stove used by the patient. Determine fuel source, whether or not stove is the ‘new design’. Select appropriate ‘control’ for each case. This is the most difficult task of a case-control study, to find persons comparable to the case in all things except the type of stove used in the home. It is well to find multiple controls for each case, drawing from different categories. For instance, a hospital ‘control’ could be a person admitted to the hospital the same day for an illness rather than an injury, who is the same gender, same socioeconomic status and in the same age group as the bum patient. A neighbourhood ‘control’ could be a person living on the same road, within a certain number of houses, who is the same gender, same socioeconomic
status and in the same age group as the bum patient. 4. Interview each ‘control’ to determine the type of stove used. Determine fuel source, whether or not stove is the ‘new design’. 5. Analyse data using simple 2 x 2 table, categorizing subjects along two axes: positive or negative for bum injuries associated with stoves, and positive or negative for exposure to ‘new stove’. Success would be achieved if those using the new stove were significantly less likely to be in the bum category. There are no published case-control studies of a bum prevention intervention. However, Aefiology of Bum Injuries Among Children Aged C-4 years: Resulfs of a Case-confrol StudyI used this design to identify risk factors for bums in young children in the Netherlands. The authors found increased bum risk among children with other than Dutch ethnicity, and children living in very small housing units, and in homes using gas for cooking.
References 1 Locke JA, Rossignol
2
3 4
5
6
7 8 9
10
11
12
13
AM, Burke JF. Socioeconomic factors and the incidence of hospitalized bum injuries in New England Counties, USA. Bums 1990; 16: 273-277. Cheng JCY, Leung KS, Lam ZC, Leung PC. An analysis of 1704 bum injuries in Hong Kong children. Bums 1990; 16: 182-184. Ebrahim MKH, Bang RL, Lari ARA. Scald accidents during water aerosol inhalation in infants. Bums 1990; 16: 291-293. Campbell DT, Stanley JC. Experimenfal and Quasi-erperimental Designs for Research. Chicago: Rand McNally College Publishing Company, 1966. Hulley SB, Cummings SR (eds). Designing Clinical Research: An Epidemiological Approach. Baltimore: Williams & Wilkins, 1988. Yoshioka T, Ohashi Y, Sugimoto H, Sawada Y, Kobayashi H, Sugimoto. Epidemiological analysis of deaths caused by bums in Osaka, Japan. Btlms 1982; 8: 414-422. Mall CN, Misgar MS, Khan M, Singh S. Analytical study of bums in Kashmir. Bums 1983; 9: 180-183. Sorensen B. Prevention of bums and scalds in a developed country. ] Trauma 1976; 16: 249-258. Mohan D, Varghese M. Confrol of Firework Injuries in India: Experiences from a Five Year Sftldy. Paper presented at the First World Conference on Accident and Injury Prevention, Stockholm, Sweden, 17-21, September, 1989. McLaughlin E, Langley JD, Laing RM. Prevention of children’s bums: legislation and fabric flammability. NZ Med ] 1986; 99: 804-807. McLaughlin E, Vince CJ, Lee AM, Crawford JD. Project bum prevention: outcome and implications. Am ] Public Health 1982; 72: 241-247. MacKay AM, Rothman KJ. The incidence and severity of bum injuries following Project Bum Prevention. Am ] Public Health 1982; 72: 248-252. van Rijn OJL, Bouter LM, Kester ADM et al. Aetiology of bum injuries among children aged 0-4~: results of a case-control study. Bums 1991; 17: 213-219.