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Accid. Anal. and Prev., Vol. 26, No. 5, 675-679, 1994 pp. Coovrieht 0 1994 Elsevier Science Ltd . , ~-“--

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THE INCIDENCE OF STAIRWAY INJURIES IN AUSTRIA

DAVID HEMENWAY,' SARA J. SOLNICK,' CHRISTIAN KOECK,*

and JOSEPH KYTIR~

‘Harvard School of Public Health, 677 Huntington Ave., Boston; 2Vienna City Hospital Association, Zelinkag 9, A-1010 Vienna; 3Austrian Academy of Sciences, A-1033 Vienna,

Hintere Zollantsstrasse 2B, Austria

(Accepted 14 March 1994)

Abstract-Stairs are among the most hazardous features of the everyday environment, yet stairway falls have received little research attention. A stratified random sample of Austrian residents was surveyed in person in 1989. Of over 55,000 respondents, 147 reported a stairway injury in the previous year that limited activity for at least one day. Thirty-seven percent of these injuries resulted in hospitalization. Extrapolating to the entire country of 8 million people, each year some 20,000 Austrians sustain serious stairway injuries resulting in over 7,500 hospitalizations. The incidence of stairway injury increases monotonically with age, and females are more at risk than males. The stereotypical stairway injury victim is an elderly woman, not highly educated, who is unmarried and living alone

Keywords-Austria, Falls, Home injuries, Stairs

Stairs are one of the most hazardous features of the everyday environment (Arches 1985). Walking on stairs requires a special gait (e.g. the toe is set down before the heel) and a high rate of energy expendi- ture. Missteps on stairs are thus quite common, and a misstep on a stair is more serious than one on a flat surface. To fall down stairs is not only to fall off a cliff, but to fall on rocks below, for the nosing of steps presents a succession of sharp edges (Tem- pler et al. 1978). Studies show that the risk of major injury per fall is thus far greater for falls from stairs than for falls on level surfaces (Nevitt, Cummings, and Hude 1991; Honkanen and Smith 1990).

Stair injuries represent a hidden epidemic. It is estimated that, in 1990, approximately one million individuals in the United States were treated for injuries involving stairs, and more than 45,000 were hospitalized (National Electronic Injury Sur- veillance System 1990). Yet stairway falls have received little research attention (Pauls 1985; Tem- pler 1992). Indeed, little is known about the associ- ation of even demographic characteristics with stairway injuries.

This study provides data on the incidence of serious stairway injuries in Austria. We examine whether various demographic characteristics-age,

gender, residential location, household size, marital status, education and job type-appear to be risk factors for stairway injuries.

METHODS

In 1989, the Austrian Central Statistical Office conducted a survey about injuries from sports and from domestic and leisure activities. The survey was part of the in-person microcensus, which is adminis- tered four times each year. Microcensus surveys are divided into two sections: the “basic program,” which includes questions concerning age, occupa- tion, household structure and other demographic in- formation; and the “special program,” which fo- cuses on varied specific topics, such as consumption patterns, health, disabilities, and, in 1989, injuries.

The sample population of the microcensus is a .9% sample of all Austrian private households. Peo- ple residing in institutions (e.g. nursing homes, pris- ons, monasteries) are not included. For the survey, all members of the household (people living at the same address) are asked to respond to the questions. By law, answering the questions is mandatory for the basic program and optional for the special pro- gram. The survey protocol permits any household

675

676 Brief Communications and Research Notes

member to answer questions for a person not present at the time of the interview, which is conducted in the subjects’ home.

The sample population is a representative sam- ple of Austrian residents stratified by age and gen- der. For the 1989 injury survey, 28,000 households were randomly selected. The total number of per- sons surveyed was approximately 60,000. Of those, 4.5% (male 4.6%, female 4.4%) declined to partici- pate in the injury survey. Among the people included in the survey, 45.4% did not answer the questions themselves (male 52.6%; female 38.9%). For these individuals, other members of the household re- sponded to the interviewers’ questions.

We examined the domestic and leisure section of the 1989 injury survey. This part of the survey encompasses all non-sports and non-work-related injuries. Respondents were asked about their most serious injury in the past year, and where it hap- pened (e.g. kitchen, roof, stairs). Respondents were also asked whether the injury was serious enough to limit activity.

We examine all reported stair injuries that lim- ited activity for more than one day. Such injuries are defined as “serious” for the purpose of this study. Respondents were also asked about the part of the body that was injured (head, trunk, extremities, mul- tiple parts), whether the injury required medical at- tention, and whether it resulted in hospitalization.

We calculated relative risks by dividing the inci- dence rate of serious stairway injury among exposed groups by the incidence rate among nonexposed groups. The chi-squared test was used to determine significance. Age-adjusted relative risks were calcu- lated using the Mantel Haenszel method (Rothman 1986).

The seven independent variables included in the analysis are: (i) age (divided into three or five age categories representing youth, middle age, and older age; and used as a continuous variable in the regression analyses); (ii) gender; (iii) location (rural, suburban or urban); (iv) household size (three categories: I, 2 or 3, more than 3 people in the household); and for adults, (v) marital status (two categories: currently married or not); (vi) education (two categories: less than 12 years of schooling or only vocational training versus 12 or more years of education); (vii) job type (two categories: unskilled nonfarm labor versus all oth- ers: self-employed, white collar, civil servant, skilled labor and apprentice).

To adjust for all risk factors simultaneously, we used multiple logistic regression to generate odds ratios as an estimate of relative risk (multivariate relative risk).

RESULTS

Of over 56,000 respondents, 147 reported a stairway injury that limited activity for at least one day. Virtually all of these injuries were the result of a fall and required medical attention. Fifty-five (37%) of the stairway injuries resulted in hospitalization. Extrapolating to the entire country of 8 million people, each year some 20,000 Austrians sustain serious stairway injuries, resulting in over 7,500 hospitalizations,

The incidence of stairway injuries increases monotonically with age (Table 1). Individuals aged 75 and over have 13 times the injury rate of children aged O-9 (66 per 10,000 vs. 5 per 10,000) and 5 times the injury rate of adolescents aged IO-19 (66 per 10,000 vs. 12 per 10,000). Stairway injuries among the elderly (65 and older) are also far more likely to result in hospitalization than the stairway injuries of persons aged O-19 (55% or 25145 vs. 31% or 4113) (Ii < .Ol).

The elderly are also at particular risk for multi- ple injuries; individuals 65 years of age and older accounted for only 28% (341122) of those receiving injuries to a single part of the body (head, trunk and extremities) but sustained 62% (8/l 3) of all multiple injuries (p < .05) (Table 2).

Injuries from stairway falls occur mainly to the extremities (Table 2). As measured by rates of hospi- talization, these injuries are typically less traumatic than those to the head. Only 32% (331104) of extrem- ity injuries required hospitalization, compared to 100% (616) of head injuries (p < .OI).

For all respondents, females and individuals liv- ing alone (i.e. household size = I) have a higher likelihood of sustaining a serious stairway injury, even after controlling for the individual’s age and residential location (Table 3) (p < -05).

Among adults (aged 20 and over), women and individuals in single-person households are at higher risk for serious stairway injury (Table 4). Individuals who are unmarried or unskilled or who have lower levels of format education are also at higher risk. Many of these independent variables are correlated; in the regression, only age, gender, and education remain significant.

DISCUSSION

In studies of falls in general (Campbell et al. 1981; Perry 1982) and stairway falls in particular (Arches 1985; Templer 1992), the elderly are at in- creased risk. Old people are more likely to have problems with vision and balance, and are thus more prone to fall when they are on stairs. In addition,

Brief Communications and Research Notes 677

Table I. Stairway injuries by age

Age (years)

o-9 IO-19 20-64 6.5-74 75 + Total

cases 3 IO x9 21 24 147 Population 6028 8160 34181 4755 3615 56739 Cases per 10,000 population s 12 26 44 66 26

Number hosp~taiized 3 I 26 IO IS 55 Percent hospitalized 100 10 29 48 62 37

31 55

because bones decrease in density with age (Trotter, Broman, and Peterson 1960), given a fall, the elderly typically sustain more severe injuries.

In our sample, the rate of serious stairway injury for those aged 65 and over was 2.5 times higher than the rate of those under age 65. The rate for individuals aged 75 and over was 50% higher than the rate for 65 to 74-year-olds. In addition, given a serious fall, the elderly in our sample were signifi- cantly more likely to be hospitalized as a result of a serious injury resulting from a stairway fall.

Studies in the United States have found that while children often fall down stairs (Gallagher et al. 1987). these falls seldom result in serious injury (Joffe and Ludwig 1988). Consistent with this find- ing, children under 10 years old in our sample have the lowest rates for serious stairway injury; although young children spend much of their time at home, only 3 of 6,000 children experienced a serious stair- way fall.

We found that women, the unmarried, those living alone, and the less educated are at higher risk for serious stairway injuries than their respective counterparts. These results are similar to those of other investigations of all falls and all fall injuries. For example, a survey of the elderly in Israel found that women as well as single people living alone reported a higher rate of falls (Cwikei 1992). In Fin- land, a study that looked at all falling injuries leading to medical treatment found that the incidence of

Table 2. Stairway falls by body injury, age, and hospitalization

Age %

Number <20 20-64 65 + Inpatient

Head 6 2 I 3 100 Trunk I2 0 7 5 58 Extremities I04 II 67 26 32 Multiple 13 0 5 8 38 Other~unknown 12 0 9 3 33 Total 147 I3 89 45 37

injuries was higher for the less educated, the unmar- ried, and females (Ryynanen et al. 1991).

Females have higher rates of falls and fall injur- ies (Prudham and Evans 1981; Perry 1982). Women have smaller and less dense bones, which may ac- count for the higher incidence of fracture and fall injury (Trotter et al. 1960). It may also be that the amount of exposure for females is greater than for males. Compared to men, women tend to spend more time at home, where most non-work-related stairway falls occur. In our study, females were sig- nificantly more likely to suffer a serious stairway injury.

Compared to those who are married, the unmar- ried behave less safely (Umberson 1987) and have fewer social supports (Verbrugge 1979). They tend to have a lower health status (Wyke & Ford 1992), to sustain more injuries (Verbrugge I979), to fall more often (Cwikel 1992), and to have more fall injuries (Perry 1982). One of the few studies focusing exclusively on stuirway falls found that the unmar- ried as well as those in lower socioeconomic groups were at particular risk for injury in Sweden (Svan- Strom 1974).

A fall is likely to result in more serious injury if medical attention is delayed. For individuals living alone, there often will not be someone on the scene to give immediate first aid or to get professional help. In our study. we found that the unmarried, and/or those living aione, are more prone to stairway falls resulting in serious injury.

Education is strongly associated with health sta- tus (Grossman 1975; Taubman and Rosen 1982). Ed- ucation is also a marker for standard of living and socioeconomic status. We found that individuals in Austria with higher education were less likely to sustain a serious injury resulting from a stairway fall.

Like the early Swedish case-control study of stairway falls leading to medical treatment (Svan- Strom 1974), we found that most injuries were sus- tamed by the extremities. In our study, head injuries

678 Brief communications and Research Notes

Table 3. Predictors of stairway falls (all respondents)

Number Cases per Age-adjusted N = 56,739 10,000 population relative risk

Multivariate relative risk

(N = 56,739) 95%

confidence interval

Age Gender

Male Female

Location Rural Suburban Urban

Household Size 1 2-3 3+

26,994 17”“’ .64 29,745 33 1 .OO (reference)

15,647 29 1.14 25,192 21 .81 15,900 36 L .OO (reference)

5,325 64*** 1.45 22,919 27 1.08 28,495 18 1 .OO (reference)

1.02***

.67* 1 .OO (reference)

1.23 .83

1 .OO (reference)

I .80* 1.09 1 .OO (reference)

(1.01, 1.03)

( .47, .95)

( .80, 1.88) ( 56, 1.23)

(1.06, 3.06) ( .72, 1.63)

Chi? = .OOOl. *Significant at the .05 level; ***significant at the ,001 level.

appear to be the most likely to lead to hospitaliza- tion. The elderly were more likely to sustain injuries to more than one bodily area.

This study has various limitations. As with all analyses which rely on survey data, there is the problem of nonrespondents. However, Aus- trians are expected to cooperate with govern- ment questionnaires as a duty of citizenship, and the response rate for this 1989 survey was high- 95.5%.

Some important cases may not have been in- cluded in the survey-such as people who died from a stairway fall. In addition, if a stairway fali was not the most serious injury of the year, it was not

recorded. Stairway injuries at work were also excluded.

The survey relied on self-reports, which may not be entirely reliable. For example, a study of the el- derly found that some forget falls and minor injuries they had previously reported (Cummings, Nevitt, and Kidd 1988). However, because we focus on injur- ies that limit activity for at least a day, we expect few respondents will have forgotten such an incident oc- curring within the past year. It is generally assumed that respondents will’more easily remember falls that caused an injury or limited the fulfillment of normal roles (Tinetti, Speechiey, and Ginter 1988).

Rather than forgetting, respondents may tele-

Table 4. Predictors of stairway fails (adults only)

Number Cases per Age-adjusted N = 42,551 10,000 population relative risk

Multivariate relative risk

(N = 33,895) 95%

confidence interval

Age Gender

Male Female

Location Rural Suburban Urban

Household Size

i-3 3-t

Marital Status Not married Married

Education Lower Higher

Job Type Unskilled Skilled

19,802 73*** 22,749 ;0

11,136 34 18,745 27 12,670 36

20,060 5,299 64”W 30 17,192 23

15,296 4,*** 27.255 26

36,158 35** 6,393 11

8,576 43* 25,319 27

I .02* (1.00, 1.03)

.69 .66* ( .44, .99) 1 .OO (reference) 1 .OO (reference)

1 .oo .9-l ( 59, 1.62) .78 .70 ( .44, i.11)

1 .OO (reference) 1.00 (reference)

1.65 1.19 1.40 1.25 ( ( .69, .78. 2.85) 2.00) 1 .OO (reference) 1 .OO (reference)

1.48 1.46 ( .92, 2.32) 1 .OO (reference) 1 .OO (reference)

3.89 3.78** I .OO (reference) I .OO (reference)

1.43 1.24 1 .OO (reference) 1 .OO (reference)

(1.37, 10.45)

( .82, 1.86)

Chi’ = .OOOi. *Significant at the .05 level; **significant at the .Ol level; ***significant at the .OOl levei.

Brief Communications and Research Notes 679

scope the past-remembering the painful episode as having occurred more recently than it actually did. Telescoping would tend to lead to an overesti- mate of the actual frequency of stairway injuries. The self-reported hospitalization rate caused by stairway falls in Austria, even excluding their work- related injuries and injuries to the institutionalized, is substantially higher than the U.S. rate determined by the Consumer Product Safety Commission from a sample of hospitals (National Electronic Injury Surveillance System 1990).

Probably the most important limitation of this study is the lack of information on many potential risk factors for stairway injuries. We have demographic data, but nothing about other personal factors found to increase the likelihood offal1 injuries, such as alco- hol consumption (Waller 1978), problems with vision (Prudham and Evans 1981; Perry 1982) and balance (Tinetti et al. 1988), or other physical or cognitive im- pairments. Moreover, information is not available about the use of stairs (exposure) or about the physi- cal environment, such as the type of stairs, banisters, carpeting, etc. (Templer et af. 1978; Arches, Collins, and Stahl 1979; Templer 1992).

This study is a large, random, population-based investigation that provides information on various household injuries. Although stairs are the most haz- ardous element of the typical residence (Carson et al. 1978) they have received little research attention (Templer 1992).

Our investigation describes the extent of the stair-injury problem in Austria and identifies demo- graphic risk factors for serious stairway falls. These include being elderly and female, with a lower level of educational attainment.

Acknowledgements-This research was supported in part by the Harvard Injury Control Center, funded by the Centers for Disease Control and Prevention. The authors would like to thank the Austrian Central Statistical Office for providing them with the microcensus data file.

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