Johanna Laiho, Susan Purdon
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SUMMARY
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5.1 INTRODUCTION AND BACKGROUND
This chapter presents findings on the incidence and characteristics of non-fatal accidents, the circumstances under which accidents occur, and the personal characteristics of those having accidents. The data presented for those aged 16-64 represent an update on the 1995 survey, and in Section 5.2.8 change since 1995 is commented on. Data is also presented, for the first time, on accidents among children and those aged 65-74.
This section explains the data on accidents and how it is presented. The rest of the chapter is divided into two main sections. Section 5.2 describes accidents in terms of their incidence, cause, location, injury, and whether or not they could have been prevented. Section 5.3 compares accident rates by social class and region within Scotland, and accident rates for Scotland with those in England.
5.1.1 Accident classification and recall period
The term 'accident' covers a very broad range of events from the extremely serious, which are of considerable importance to those monitoring health in Scotland, to the essentially trivial. In order to concentrate on the more salient events, the definition of 'accident' used in the Health Survey is 'any accident about which advice was sought from a doctor, nurse, or other health professional'.
Informants were asked to recall how many accidents they had in the 12 months prior to interview about which they saw a doctor, nurse or other health professional. For those having had at least one accident, detailed information about the nature and cause of the most recent accident was collected. The reference period of 12 months before interview was chosen so as to be sufficiently long to generate details of enough accidents for analysis yet short enough for informants accurately to remember all, or at least a high proportion of, their accidents.
5.1.2 Coverage of accidents
The survey covers most, but not all, accidents. Firstly, because the Health Survey covers only the household population, accidents to those in the rest of the population are excluded. Furthermore, since the Health Survey collects data directly from informants, fatal accidents are excluded. In addition, there will be under-representation of accidents that lead to long-term hospitalisation -indeed all accidents leading to twelve months' hospitalisation will be excluded. Finally, accidents that lead to a move out of the household population into the institutional population will also be excluded. For these reasons, the accident rates presented in this chapter can best be described as non-fatal accident rates for the household population. These rates will be slight under-estimates of true accident rates because of the exclusions, which apply particularly to older people. However, since the great majority of accidents do not lead to long-term stay in hospitals or other institutions, the downward bias should be small.
5.1.3 Accident rates and weighting to compensate for selection bias
The incidence of accidents is presented in terms of 'annual accident rates per 100 persons'. That is, the mean number of accidents over a 12 month period multiplied by 100.
Although informants were asked to specify the total number of accidents they have had over the period 12 months before the interview, detailed information was collected on only the most recent accident. This selection process leads to the over-representation of accidents to people for whom accidents are relatively uncommon events, and this over-representation could, in principle at least, bias the survey estimates. (For example, an informant who had three accidents in the last year would contribute only as much information as an informant who had just one accident.) To avoid bias, analyses that use the detailed data on individual accidents use an additional 'accident weight', which is multiplied to the more general survey weight. The 'accident weight' per informant is calculated as equal to the total number of accidents in the 12 month reference period.1 In practice relatively few informants reported having had two or more accidents so the impact of the accident weight on estimates is fairly small.
5.2 THE INCIDENCE OF ACCIDENTS AND THEIR CHARACTERISTICS
5.2.1 Accidents by age and sex
For adults aged 16-74, 17% of men and 11% of women reported having had at least one accident within the previous 12 months about which they saw a health professional. Three percent of men and 1% of women reported having had two or more accidents in the same period. Converting these figures to accident rates, the annual accident rate for men aged 16-74 was estimated at 21 per 100 men, and for women at 13 per 100 women.
Among boys aged 2-15, 20% had had at least one accident within the last 12 months, and 5% had had two or more. The annual accident rate was estimated at 25 per 100 persons. For girls within the same age range the incidence of accidents was considerably lower, just 14% having had at least one accident, and 2% having had two or more accidents. The accident rate for girls aged 2-15 was estimated to be 17 per 100 persons.
Figure 5A illustrates the trend in accident rates by sex and age over the whole of the age-range 2-74. Boys and men had higher accident rates than girls and women of comparable age throughout ages 2-44, although for both sexes the accident rates show broadly the same relationship with age. Accident rates were particularly high for men aged 16-24 (at 41 per 100). After the age of about 54, accident rates for women start to exceed those of men.
Figure 5A Annual accident rate (5 year moving average), by age and sex
5.2.2 Accidents in and out of work
Tables 5.3 and 5.4 respectively show accident rates at work and outside of work for adults, by age and sex. The accident rates for accidents outside of work are shown per 100 persons in the population, whereas the work-based accident rates are calculated per 100 persons in work.
The work-based accident rate is calculated as the total number of accidents at work over the 12 month reference period divided by the number of people in work, and multiplied by 100. The denominator is estimated from the survey data as those whose main activity status at the time of interview was 'in paid employment'. Since this number will exclude some persons whose main activity was other than 'in paid employment' but who nevertheless had a paid job (some students will, for example, fall into this category), the denominator will be slightly too small and the estimated accident rates slightly too large. Nevertheless, the biases should be small.
The overall work-based accident rate for men was 11 accidents per 100 persons in work, and was strongly related to age, the highest rates being associated with the young. The work-based accident rate for women was consistently lower than that for men for those aged 16-54; for those aged 55 and over there was no significant difference between men and women. In contrast to the pattern for men, there was no marked relationship between age and work-based accidents for women, the overall work-based accident rate being three per 100 persons.
Figure 5B Work-based accident rate for adults (5 year moving average), by age and sex
Although a fairly high proportion of accidents to informants occurred at work, the majority of accidents happened when the informant was not at work (65% of accidents to men and 88% of accidents to women, these percentages including informants who were not in work). The overall non-work accident rate for men was 14 per 100 persons; the rate for women was 12 per 100. For accidents outside of work, the relationship between accident rates, age and sex was broadly the same as for work-based accidents, although there was less of a gap between the accident rates by sex (either overall, or within age-groups). In addition, the non-work based accident rate for women was significantly higher amongst those aged 16-24, at 20 accidents per 100 women, than the rate for the next age-group, 25-34, at 11 accidents per 100 women. For those aged 55-74 the non-work accident rates for women were estimated to be close to double those for men.
Figure 5C Non-work accident rate for adults (5 year moving average), by age and sex
5.2.3 Causes of accidents
Informants who had at least one accident in the reference period were asked to describe the cause of their most recent accident. Their responses were coded by interviewers into ten categories of accident2:
Some caution is needed in the interpretation of the data on cause of accident derived from this interviewer coding. What is coded in individual cases will depend firstly upon how the informant describes the accident and secondly on how the interviewer interprets that description. For example, an accident in which a person sprains their ankle when jogging may be described as a fall by one informant ('I fell and sprained my ankle') or as a sporting accident by another ('I sprained my ankle when I was out jogging'). If the informant describes the accident to the interviewer as 'I fell and sprained my ankle when I was running' then some interviewers may code this as a fall automatically whereas others may probe further, establish that 'running' was actually jogging, and code it as a sports accident. Interviewers were briefed to code more than one category per accident if appropriate, the intention being to collect as full a description of the accident as possible in order to avoid misclassification. One obvious implication of the ambiguity in coding is that accident rates cannot be reliably derived for different types of accident.
Tables 5.5 and 5.6 give the causes of accidents (both in and out of work), by age and sex for adults and by age for children. (The sample size of accidents for children is too small for separate estimates by sex to be made reliably.) For adults the most commonly coded type of accident for both sexes and across all age groups, was a fall or trip, but beyond this there was considerable variation by age and sex. Between the ages of 16-44, about 18% of the accidents to men were described as sports or recreational accidents; and a similar percentage were described as being caused by a tool, implement or equipment. Notably, after the age of 44 the percentage of men's accidents described as sports or recreational drops rapidly. Amongst men aged 16-24, 13% of accidents were described as being caused by another person (including attacks).
Accidents to women aged 16-24 were, after falls, most commonly attributed to sports and recreation. For older women falls were the only dominant cause, this being particularly true for women in the 65-74 age group, who described 80% of their accidents as being caused by a fall or trip.
Six percent of accidents to adult men, and 8% of accidents to adult women were described as road traffic accidents. Small proportions of accidents were attributed to other causes such as being hit by a falling object (5% of accidents to men and 4% for women), burns or scalds (2% for men and 3% for women), and lifting (3% for both sexes).
For children aged 2-15 the majority of accidents (51%) were described as falls. The clearest trend by age was that, with increasing age, more accidents were described as sports or recreational (35% of accidents to those aged 13-15 compared to less than 10% for those aged six and under).
Table 5.7 gives the causes of accidents at work. The most common cause of work-based accidents was the use of a tool, implement or piece of electrical or mechanical equipment (32% of work-based accidents). Close to a quarter (24%) of all accidents involved a fall or slip, and 9% of accidents were caused by lifting some object. The profile of accidents differed by sex, women being more likely than men to report the cause as being a fall, or another person, and less likely to report the use of tools or implements as the cause.
5.2.4 Location of accidents
For adults, there was a very strong relationship between age, sex, and the location of accidents, which must, in large part, reflect differences in lifestyle with increasing age, and between the sexes. Relative to men, a far higher percentage of the accidents to women occurred in the home or garden (43% of accidents to women compared to 21% of accidents to men). Relative to women, accidents to men were twice as likely to occur in either places for sports or recreation or workplaces and other public buildings (53% of accidents to men compared to 27% of accidents to women).
For accidents to men, with increasing age higher percentages of accidents occurred either in the home or garden or outdoors (excluding sports and recreational areas). For younger men, in particular those aged 16-24, most accidents occurred in places for sports or recreation, the workplace, or other public buildings. A similar change with age was apparent for women, but for women in the younger age-groups, a higher proportion of accidents occurred in the home than was the case for men of comparable age.
The youngest children (aged 2-3) experienced most of their accidents in the home or garden (80%). This proportion decreases rapidly with age: for children aged 13-15 the figure was just 12%. For older children, close to one-half (46%) of all accidents occurred in places for sports or recreation.
5.2.5 Type of injury
Informants were asked to describe the injuries caused by their accident using twelve categories of injury:
For each accident, all relevant categories were recorded.
Table 5.10 shows the distribution of types of injury by sex and broad age-band for adults. Table 5.11 gives this information for children in three age groups. Of the accidents experienced by adults, the most commonly cited injuries were swelling or tenderness (44%); straining or twisting (36%); bruising, pinching or crushing (35%) and cutting and grazing (26%). For both sexes, about 13% of accidents resulted in broken bones. There were no major differences in injury by age, but there is some evidence that older women were more likely to suffer broken bones (17% of the accidents to women aged 45-74 resulting in a broken bone).
Overall, the frequency of injuries reported was similar for children as for adults, although accidents to children, and especially young children, were less frequently described as strains or twists. Accidents to children under 10 were more frequently cuts and grazes than was the case for older children or adults. Twenty percent of accidents to children aged 7-15 resulted in broken bones compared to just 5% of accidents to those aged 2-6.
5.2.6 Source of help or advice about accidents
In 66% of the accidents to men and 67% of the accidents to women, help or advice was given at a hospital. In around one quarter of these accidents to men, and two-fifths of these accidents to women, help or advice was also given by a GP or a nurse at a GP surgery (although the order of visit was not established). For the majority of other accidents help or advice was given solely by a GP or a nurse at the surgery. For a small percentage of accidents (10% for men and 7% for women) help or advice was given by some other medical professional.
Children were significantly more likely than adults to visit a hospital about their accidents. For 76% of accidents to children help or advice was sought from a hospital. In 34% of cases help or advice was given by a GP or a nurse at a GP surgery (the overlap between the two being 15%).
Table 5.14 shows source of help or advice for accidents to adults by type of injury. The figures need to be interpreted with some caution because the categories of injury are not mutually exclusive. For example, some of those reporting bruising may also have broken a bone. Nevertheless, some fairly predictable differences do emerge. Advice was sought from a hospital for most accidents (92%) that resulted in broken bones, but in considerably fewer accidents (53%) that resulted in strains or twists.
5.2.7 Time off work and school
Table 5.15 gives the percentage of adults who were in paid work at the time of their accident who took time off work because of their accident.Table 5.16 gives the percentage of school-aged children taking time off school.
Overall, time was taken off work for 54% of the accidents to men in paid work and for 58% of the accidents to women in paid work. For women there was no clear trend in the percentages with age. For men, those aged 16-34 were more likely to take time off work than men aged 35 and over.
Time was taken off school for 44% of accidents to children aged 4-15.
5.2.8 Prevention of accidents
Informants were asked to judge whether or not anything could have been done to prevent their accident, and, if so, whether the accident could have been prevented by the informant themselves or by others. For 51% of accidents to adult men and 49% of accidents to adult women, the informant thought that the accident could not have been prevented. Of the remaining accidents, 65% of accidents to men and 52% of accidents to women were perceived to be preventable by the informant themselves, and 35% of accidents to men and 48% of accidents to women were preventable by others (a small percentage being preventable by both).
For children a slightly smaller percentage (43%) of accidents were perceived to be preventable.
Preventability of accidents differs by the location of accidents. For accidents that happened in a place for sports or recreation, just 26% of accidents to men and 22% of accidents to women were judged to be preventable, the percentages for all other locations being close to or over 50%. For accidents to children, outdoor accidents (other than in gardens, or places for sports or recreation) were seen as the most preventable (at 60%, compared with about 35-40% of other accidents).
5.2.8 Changes in the accident rates between 1995 and 1998
Table 5.19 gives accident rates per 100 adults, by age and sex, for the 1998 and 1995 surveys. Although the accident rates estimated in the 1998 survey were marginally lower than for the 1995 survey, the differences are not significant. It is not possible to say at this stage whether or not there is a trend towards fewer accidents.
Table 5.19
5.3 ACCIDENTS, SOCIAL CLASS AND REGION
5.3.1 Accidents and social class
Adults' work-based accident rates, non-work accident rates and all accident rates, by age, sex and social class are shown in Table 5.20. Children's accident rates, by age and social class, are shown in Table 5.21. Social class is defined in terms of the informant for adults and in terms of the chief income earner in the household for children. (For adults the social class of the informant is used because it is a better explanatory variable for work-based accidents than the social class of the chief income earner. Social class is used here as an indicator of the type of work done rather than as an indicator of social position.)
For adults, there was no clear relationship between social class and the non-work accident rate. In contrast, there was a very clear relationship between social class and the work-based accident rate. For both age groups shown, and both sexes (with the possible exception of women aged 45-74) the work-based accident rate was consistently higher than average for those in Social Classes IIIM, IV and V. The relationship was particularly strong for men in the 16-44 age-group, for whom the work-based accident rate was four times higher in Social Classes IIIM, IV and V than in Classes I, II and IIINM. These findings confirm those found in the 1995 Health Survey, a very similar relationship with social class being found at that time.
Across all age-groups, the accident rates for children were significantly higher than average for those in Social Classes IV and V, with children in this group having four extra accidents per 100 children per year compared to the overall average.
5.3.2 Regional variations in accident rates
Adults' work-based accident rates, non-work accident rates and all accident rates, by age, sex and region, are shown in Table 5.22. Accident rates for children, by age and region are shown in Table 5.23.
Overall there were few, if any, significant differences between the regions, and the differences observed should not be over-interpreted. A finding from the 1995 Health Survey that is confirmed in the 1998 survey, is that the work-based accident rate for men aged 16-44 was significantly lower in Greater Glasgow than in the rest of Scotland. This finding was largely 'explained' in 1995 by the fact that a greater than average proportion of men in Greater Glasgow work in the service sector, where the work-based accident rate was lower than average.
5.4.2 Comparison with English accident rates
The Health Survey for England collected data on accidents in 1995 and 1996 for adults and in 1995, 1996 and 1997 for children. Although the definition of an accident was the same in the English and Scottish surveys, one key difference between the two surveys was that the reference period used in England was six months, rather than the 12 month reference period used here. In the absence of evidence to the contrary, it is assumed that the difference in reference periods does not affect the comparability of the estimates, although it is possible that recall bias in Scotland may account for at least some of the differences described in the paragraph below. (An analysis of the 1995 Health Survey for England data3, where data was collected on the number of accidents per month, suggested that there was some recall bias using a six month reference period, slightly fewer accidents being recalled from the earliest months of the period. For adults it was estimated that the English data would have given an accident rate of 20.8 per 100 if a reference period of 1.5 months had been used (that is, measured from the start of the previous month to the time of interview, and assuming interviews are evenly spread throughout each month). This compared to an accident rate of 19.9 per 100 for the full six month reference period. It is probable that this bias would be slightly larger using a 12 month reference period.)
Tables 5.24 and 5.25 give annual accident rates by age and sex for Scotland, all England, and Northern England. For adults, there were no significant differences between Scotland and all England; comparing Scotland with Northern England, the rates in Northern England were consistently slightly higher than in Scotland, with the single exception of men aged 16-24 where the rates were the same. For children, accident rates were, almost without exception, lower in Scotland than in all England, the difference being even greater when comparing Scotland to just Northern England.