Occupational and Environmental Medicine 1997;54:785-792

Injuries after falls at work in the United Kingdomand Sweden with special reference to fractures inwomen over 45

R McNamee, K Kemmlert, L Lundholm, N M Cherry

AbstractObjectives-To describe the relation withage of risk of reported injury after a fallamong women at work in two countries,the United Kingdom and Sweden, withparticular emphasis on fractures, and tointerpret these data.Methods-Rates of accidents compiledunder the national reporting regulationsof each country during a two year periodwere described by age, sex, cause (fall onthe level, fall from a height, other), andoccurrence of fracture, with emphasis onthe relative risk (RR) in workers aged 45years and over compared with those agedunder 45. For fractures (major fracturesonly in the United Kingdom) amongwomen, RRs were calculated for all occu-pations, with the three digit occupationalclassification schemes of each country.Summary RRs for older versus youngerwomen, directly standardised for occupa-tion, were derived.Results-Among women, RRs for injuryafter a fall on the level and fall from aheight were 2.77 and 1.77 respectively inSweden and 2.28 and 1.54 in the UnitedKingdom. When restricted to fractures,the RRs became 4.75 and 3.66 respectivelyin Sweden and 3.35 and 1.97 in the UnitedKingdom. Standardisation for occupationgave RRs for fractures of 4.87 and 3.75 inSweden and 3.43 and 2.16 in the UnitedKingdom. Almost all occupational groupswith enough fractures for analysis showedan excess of fractures related to fallsamong older women. A different agepattern was seen for all injuries orfracture after other types of accidents andfor all types of accident in men.Conclusion-It is argued that, for frac-tures at least, the results for women areunlikely to be due to reporting bias andunlikely to be explained by a greater expo-sure to workplace hazards among olderwomen. Whether there is an increasedrisk of falling, as distinct from sustaininga fracture, is not clear. The generality ofthe increased risk suggest that effortsshould be made to minimise hazards in alloccupational sectors, particularly thoseusing many women.

(Occup Environ Med 1997;54:785-792)

Keywords: age; fractures; falls

Since 1990 in the United Kingdom, falls on thelevel have accounted for one third of majorinjuries and about 20% of lesser injuries'reported by employees under the United King-dom Reporting of Injuries, Diseases and Dan-gerous Occurrences Regulations (RIDDOR)1985. In 1990-1 in Sweden, falls accounted for17% of all occupational accidents reportedunder the Swedish Occupational Injury Infor-mation System (ISA). A recent article byLeamis and Murphy' found that falls ac-counted for 24% of the total cost of claims to aworkers' compensation insurance schemewhich covered about six million workers in theUnited States.For accidents at work in general, there are

considerable differences in the rates for menand women,3 probably reflecting the predomi-nance of men in the higher risk occupations inwestern countries. For example, the UnitedKingdom RIDDOR data suggest that men areabout three times more likely to sustain aninjury at work than women.' Swedish ISA datasuggest a relative risk (RR) of about 2.3 formen compared with women. Leamis andMurphy reported similar rates for men andwomen from falls on the level but almost threetimes as many falls from a height among men.The variation in the rate of occupational

accidents due to falling, as a function of bothage and sex, has received little attention. In areview of the literature on aging and occupa-tional accidents, Laflamme and Menckel3found that older workers were more likely tofall, whereas Leamis and Murphy found thehighest rate of fall accidents in youngerworkers. Neither paper distinguished betweenmen and women. Agnew and Suruda,4 whoconcentrated on fatal work related falls amongmen as recorded by United States national reg-isters, found that the rate increased after age45. A recent internal document by the UnitedKingdom Health and Safety Executive showedthat the rate of reported major injuries due tofalls rose sharply after age 45 in women but notin men. This pattern had not hitherto beennoted in the United Kingdom or elsewhere.The present work, which used data fromnational reporting schemes in two countries-the United Kingdom and Sweden-stems fromthis initial observation.

It has been estimated5 that perhaps only onein three reportable accidents were actuallyreported under the United Kingdom RIDDORscheme. Therefore one hypothesis to beconsidered here is whether the age related

Centre forOccupational Health,School ofEpidemiology andHealth Sciences,University ofManchester,Manchester M13 9PTR McNameeN M Cherry

National Board ofOccupational Safetyand Health, S-171 84Solna, SwedenK KemmlertL Lundholm

Correspondence to:R McNamee, Centre forOccupational Health, Schoolof Epidemiology and HealthSciences, University ofManchester, ManchesterM13 9PT.

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trend in falls among women might be due toreporting bias-that is, an increased likelihoodof reporting among older women. A secondquestion is whether the apparent age effect inwomen might be an artefact of job differencesbetween older and younger women. Thirdly, itwas noted that injuries classified as majorunder the RIDDOR scheme were mainly frac-tures; this raised the question of whether anyexcess risk represents an increased likelihood offalling or an increased risk of fracture during afall, or both. Finally, if the trend with age wasconsidered to be real, then the identification ofkey occupations which accounted for theexcess cases would be important.

Initially, the investigation was carried outwith data from the United Kingdom collectedunder that country's national reporting regula-tions, RIDDOR 1985. The advantage of com-parison with data collected under a differentsystem was soon recognised and the enquirywas subsequently extended to the Swedennational reporting scheme, ISA. Another ob-jective was then identified: to see whether theoccupational distribution of falls at workamong women was similar in the two countries.Neither dataset contained information whichmight be used to consider the role of personalcharacteristics, other than age and sex, in thecausation of accidents at work.

MethodsUNITED KINGDOMUnder the United Kingdom RIDDOR 1985scheme, three categories of work relatedinjuries were required to be reported byemployers to the relevant enforcing authority:fatal injuries, other major injuries, and injuriesresulting in absences of more than three daysaway from work. Appendix 1 shows the defini-tion of the category major injuries as usedunder RIDDOR. For the present study, data onall injuries among male and female employeesduring April 1991 to March 1993, (except thefew fatal injuries), were obtained and classifiedby sex, age, cause, and whether or not afracture occurred. Causes of injuries were clas-sified in three groups: falls on the same level,falls from a height, and other causes.

Occupational data from the United King-dom census 1991 had been coded according tothat country's 1990 standard occupationalclassification (SOC), but unfortunately thesame system had not been used for RIDDORdata. To enable injury rates by occupation to becalculated, recoding of occupational infor-mation with the SOC scheme was necessary.This was carried out by an experienced coderfor major injuries among women only, aswomen were the main focus of the study. Someoccupational sectors (commercial, retail, lei-sure, and the entertainment businesses) had tobe excluded from this analysis as these were notrequired under RIDDOR to supply job titleinformation. Furthermore, as most major inju-ries were fractures, it was decided to concen-trate on these in the occupational analysis. TheSOC three digit coding system distinguishesalmost 400 occupational groups; the first digit

alone enables a classification into nine majorgroups.The number of employed women by age

(two groups, 16-44 and 45-64) and SOCgroup in the United Kingdom in 1991 wasestimated with a combination of data from the1991 census and from the United Kingdomlabour force survey. (Available census data gaveonly the total number of women in each SOCthree digit group; data from the labour forcesurvey was used to provide estimates of thepercentages of women in each age group xthree digit SOC group, and these percentageswere applied to the census data.) Rates ofinjury in each SOC group by age and causewere found by combining RIDDOR (numera-tor) data with these estimates as the denomina-tors.

SWEDENUnder the Swedish Work Injury Insurance Act1976,6 Swedish employers are required to senddetails of all occupational accidents to thesocial insurance office, which forwards copiesto the labour inspectorate, the fieldorganisation linked to the National Board ofOccupational Safety and Health. All occupa-tional accidents resulting in at least one dayaway from work, or in a dental injury, are regis-tered in the National Board's information sys-tem, ISA.For the present study, all injuries registered

in Sweden during January 1990 to December1991 were obtained and classified as for theUnited Kingdom data. Under ISA, there is noequivalent to the Health and Safety Executivedefined major injury group; for comparisonwith the United Kingdom occupational analy-sis ofmajor fractures, an analysis of all fracturesamong women by occupation, age, and causewas carried out. The occupationalclassification system for injuries and for the1990 Swedish census was the Nordisk YrkesKlassificering (NYK) scheme. As in the UnitedKingdom system, this uses a three digit codewhich distinguishes almost 400 occupations;the first digit of the code defines 10 majorgroups.

Underreporting of injuries is acknowledgedin both countries, with the problem beinggreater in the United Kingdom (see earlier)than in Sweden (small scale studies haveestimated reporting rates in the range 77%-100% depending on the occupation). There-fore the absolute rates given here will underes-timate the true rates of such injuries. Also,differences in the reporting regulations meanthat rates of reported injuries for Sweden willtend to be higher than for the UnitedKingdom, when the true rates are equal.Furthermore, in the United Kingdom, certainbusiness sectors (commercial, retail, etc) wereexcluded from the numerators of rates but notalways from the denominators. Overall there-fore, limited reliance can be placed on theabsolute rates, and differences between coun-tries or occupations should be interpreted cau-tiously. However, contrasting rates of RRs inwomen aged 45 and over with those under 45within the same occupational group, will not

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Injuries afterfalls at work in the United Kingdom and Sweden

Table 1 Scheme of analysis: type of injury by factors analysed in each country

Analysis by

Populations studied Age 16-44 n Age 45-64 n Age + cause Age + cause + occupation

Sweden 1/90-12/91 employees + self employed:Women 1 380 432 744 977 All injuries + all fractures All fracturesMen 1 460 945 802 918 All injuries + all fractures No analyses

United Kingdom 4/91-3/93 employees only:Women 6 795 738 2 901 512 All injuries + all fractures All major fracturesMen 7 474 099 3 384 206 All injuries + all fractures No analyses

Table 2 Reported accidents at work in two countries by sex, cause, and age*

2y rate per 100 000

AgeRR (95% CI)

16-44 45-64 45-64 v 16-44

Reported under ISA, Sweden 1990-1:Women:

Falls on level 211 584 2.77 (2.64 to 2.90)Falls from height 75 133 1.77 (1.63 to 1.93)Other causes 1659 1651 0.99 (0.97 to 1.02)

Men:Falls onlevel 323 475 1.47 (1.41 to 1.53)Falls from height 142 479 1.09 (1.04 to 1.12)Other causes 4845 3540 0.73 (0.72 to 0.74)

Reported under RIDDOR, United Kingdom 1991-3t:Women:

Falls on level 158 361 2.28 (2.22 to 2.35)Falls from height 40 61 1.54 (1.45 to 1.63)Other causes 422 503 1.19 (1.17 to 1.22)

Men:Fallsonlevel 361 408 1.13 (1.11 to 1.15)Falls fromheight 189 248 1.31 (1.27 to 1.35)Other causes 1476 1338 0.91 (0.90 to 0.92)

* To simplify the presentation, only rates are shown; the numbers of accidents in the various cat-egories can be calculated from these given the sizes of the populations at risk (see table 1).t United Kingdom data excludes fatal accidents and accidents among the self employed.

suffer from biases to the same extent; conse-quently these are the main focus of the study.The main purpose of the analysis by occupa-

tion was as a means of (partially) controllingfor confounding by occupation. If occupationaldifferences explain the increased rate amongolder women then, in theory, a comparisonbetween older and younger women doing thesame job would show no difference betweenthe two age groups. To estimate the overall RRfor older women compared with younger

Table 3 Fracture rates due to falls at work as reported in two countries, by sex, cause, andage*

2 y rate per 100 000

AgeRR (95% CI)

16-44 45-64 45-64 v 16-44

Reported under ISA, Sweden 1990-1:Women:

Falls on level 42 199 4.75 (4.30 to 5.21)Falls from height 13 47 3.66 (3.17 to 4.13)Other causes 93 131 1.41 (1.30 to 1.53)

Men:Fallsonlevel 80 148 1.84 (1.71 to 2.01)Falls from height 122 182 1.49 (1.39 to 1.60)Other causes 423 416 0.98 (0.94 to 1.03)

Reported under RIDDOR, United Kingdom 1991-3t:Women:

Falls onlevel 34 115 3.35 (3.21 to 3.57)Falls from height 9 19 1.97 (1.76 to 2.21)Other causes 36 37 1.01 (0.94 to 1.09)

Men:Falls onlevel 61 78 1.27 (1.21 to 1.33)Falls fromheight 57 80 1.40 (1.33 to 1.47)Othercauses 176 154 0.87 (0.85 to 0.90)

* To simplify the presentation, only rates are shown; the numbers of accidents in the various cat-

egories can be calculated from these given the sizes of the populations at risk (see table 1).t United Kingdom data excludes fatal accidents and accidents among the self employed.

women in each country, adjusted for anydifference in their jobs as given by the nationaloccupational classification scheme, directlystandardized RRs were calculated. In these cal-culations, the standard population in eachcountry was defined as the occupational distri-bution, at the three digit coding level, of allwomen combined. Table 1 summarises theanalyses.To calculate 95% confidence intervals (95%

CIs) for RRs, the numbers of events in anysubgroup was assumed to follow a Poisson dis-tribution.The analysis by occupation was also used to

identify occupational groups which contributedparticularly high numbers of reported fracturesdue to falls. Although it is acknowledged that thereported rates are only estimates of the truerates, in the absence ofany other indicators theseare used to highlight groups worthy of furtherinvestigation. For each occupation the excessnumber of falls amongwomen aged 45 and over,was defined as follows:

excess number= O-Ewhere O=observed number of events in

women over 45, and E=expected number inwomen aged 45 and over, based on the rate forwomen under 45 in the same occupation. Thismeasure may also be expressed as:

excess number= (number of women aged¢45) x (rate in women aged <45) x (RR-1).

ResultsSWEDENThere were 44 484 reported accidents amongSwedish women aged 16-64 in the two yearperiod 1990-1, of which 9289 (21%) werefalls. The risk of a reportable fall at workamong women aged 45-64 years was 2.51times that for women aged 16-44; the agegradient seemed to be sharper for falls on thelevel (RR 2.77) than for falls from a height (RR1.77). There was no increase with age in therisk of accidents due to other causes (RR 0.99).As expected, Swedish men tended to have a

higher risk of a fall than Swedish women; thiswas particularly true for falls from a height(table 2). However, there was a much smallerincrease with age in the risk of either type of fallamong men. This meant that, although youngmen had a higher risk than young women of a

fall on the level, after age 45 the positions ofmen and women were reversed. On the otherhand, the risk of a fall from a height was higheramong men than women in both age groups,despite the greater age related RR for women.

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Figure 1 Relative risk offracture among older women by cause and major occupatiogroup: Sweden.

group: the United Kingdom.

UNITED KINGDOM

In the United Kingdom there were 74

non-fatal reported accidents among wi

employees in the two year period, of v

37% were falls. Age was unknown for

(9.5%) and a further 291 were outside th

and cause were broadly similar to tho

Sweden-RRs for women aged 45-64 yeajcompared with younger women for a fall

level and a fall from a height were 2.2E1.54 respectively (table 2). There was a

smaller increase with age in the risaccidents due to other causes among wc

As in Sweden, men in the United Kingdom.higher absolute risks than women but th

gradients were much weaker than for wc

When the analysis was restricted to accidwhich resulted in fractures, the age gra

among women both from Sweden an(United Kingdom became steeper-RRfalls on the level and falls from a height weSweden, 4.75 and 3.66 respectively, and

United Kingdom, 3.35 and 1.97 respec

(table 3). There was a small increase witin the risk of fractures due to other causSweden (RR 1.41) but not in the United Idom (RR 1.01).

A more detailed analysis by age o

fracture data from United Kingdom washowed that the risk associated with falls c

level more then doubled in the ageg

45-54 (RR 2.58 compared with women aged16-44) and continued to increase at ages55-64 (RR 4.98 compared with women aged16-44). A similar age trend occurred forfractures due to falls from a height (RRs of 1.57and 2.83 for 45-54 year olds and 55-64 yearolds respectively).

In each country, there was also evidence ofan increase with age among men in the risk ofa fracture after a fall on the level, but the RRswere much smaller than for women. In bothcountries, as was the case in Sweden for all fallson the level, older women had a higher risk offracture after a fall on the level than older men,whereas the opposite was true for the youngerage groups. On the other hand, men had thegreater risk of fracture after a fall from a height

mal in both age groups.

RRS STANDARDISED FOR OCCUPATIONOccupational information was available for93% of fractures reported in younger Swedishwomen and 97% of those in older women, giv-ing a total of 4640 events for analysis. (Thisdifference meant that the crude RRs forfractures based on those with occupationalinformation were slightly biased upwards: 4.91for falls on the level, 3.76 for falls from a height,and 1.49 for other causes.) Standardisation foroccupation hardly changed the estimates ofRRs: these became 4.87 (95% CI 4.40 to 5.39)for falls on the level, 3.75 (95% CI 3.08 to4.53) for falls from a height, and 1.56 (95% CI1.42 to 1.71) for other causes.There were 6465 reported major fractures

Pal among women aged 16-64 in the UnitedKingdom for whom age was recorded. Occupa-tional information had not been recorded forthe 27% in the excluded sectors (see methods)

6 589 and there was insufficient detail for occupa-omen tional coding of a further 373 fractures, leavingvhich a total of 4346 (67% of the total) for analysis.7309 Most of these (3129) were caused by falls onie age the level.h age For those with occupational information, theose in crude RRs for major fractures reported in thers old United Kingdom resulting from falls on the)n the level, from falls from a height, and from other3 and causes were 4.10, 2.47, and 1.01 respectively.much Standardisation for occupation reduced thesesk of to 3.43 (95% CI 3.18 to 3.70), 2.16 (95% CI)men. 1.78 to 2.64), and 0.88 (95% CI 0.75 to 1.03)n had respectively. The reduction in the estimatedLe age age effect after standardisation can be ex-)men. plained by the high rate of accidents in majoridents group 9 (which comprised mainly unskilledlients manual jobs in sales and services) combinedd the with the unequal proportions of older andLs for younger women employed in these jobs: 16%!re, in of women aged 45-64 compared with 8% ofin the women aged 16-44.:tivelyh age RRS FOR SPECIFIC OCCUPATIONAL GROUPSses in Figures 1 and 2 show the RRs for older womenKing- compared with younger women, of accidents

involving a fracture (major fracture only in thef the United Kingdom) for each type of accident andomen each major occupational group in the twoin the countries. These occupational groups are: ingroup Sweden; code description:

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Injuries after falls at work in the United Kingdom and Sweden

12 --A

10 -

La

aL 6 -

L 4-

2

0-

nQ

(D

Total numMedian RF

2 3 4 5 6

RR

6 B

4-

o_~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1.0 1 2 3 4 5 6

RR

35 -c

7 8

Total numlMedian RF

7 8

Total numlMedian RF30 -

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Figure 3 Relative risk offracture by cause in selectedfemale occupai

0 Professional and techni1 Health, nursing, and so

2 Managerial and admini3 Sales work4 Agriculture, forestry, fis6 Transport and commur7 Production work I8 Production work II9 Service work.Swedish major group 5 (m

ing) is very small and was theIn the United Kingdom; cc

1 Managers and adminisi2 Professional occupatior3 Associated professional4 Clerical or secretarial5 Craft and related occur6 Personal and protective8 Plant and machine ope9 Other occupations.As injuries in the United

sector did not supply occupatthat could be used, major grcpations) was omitted.

Comparisons between matwo countries are problematitions have a different strucSwedish system, the Uclassification depends on theas well as area of work. Nui

ber of groups = 63 may be classified in either SOC major group 3R= 5 1 or major group 6 depending on seniority,whereas they would all be classified as group 1

in Sweden. The United Kingdom data refer tomajor fractures only. Nevertheless the overallpicture in the two countries is similar in thatthe RR of fracture due to a fall on the level, for

E MOEN= older versus younger women, is increased in all9 10 11 12 groups (range of RRs, 2.8-8.0 in Sweden and

2.6-5.8 in the United Kingdom). Relative risksof fractures due to falls from a height were sig-nificantly increased for all groups in Sweden

ber of groups = 20 except group 4 (agriculture, forestry, and fish-R= 5.2 ing) and all groups in the United Kingdom

- with the exception ofgroup 5 (craft and relatedoccupations). The increase in risk of fracturedue to falls from a height tended to be less than

9 --- 10 - 1 1 1 2 for those due to falls on the level (range ofRRs,1.2-5.6 in Sweden and 1.0-4.2 in the UnitedKingdom).

Finally, for fractures resulting from othercauses, the RRs were much lower again (range,

ber ofgroups 74 0.9-2.1 in Sweden and 0.6-2.5 in the UnitedR= 1.4 Kingdom). Many of the Swedish groups

showed significant increases with age, whereasin the United Kingdom one group (group 9,other occupations), showed a clear decrease inrisk among older women (RR 0.6, 95% CI 0.4to 0.7).

Figures 3 and 4 show RRs when occupationis classified at the three digit level; RRs foroccupational groups with at least five fracturesin total and at least one fracture in the youngergroup are included. The generality of theincreased risk in older women of fractures after

9 10 11 12 falls on the level is notable with only a fewgroups in either country having RRs less thanone. For the smaller number of groups with

tional groups: Sweden. sufficient fractures after falls from a height, the

~cal work RRs also tended to be increased although the

cial work increase in the United Kingdom was not asstrative work notable as for falls on the level. On the other

hand, the RRs for fractures from other causeswere much lower, being centred around unity

ahing work in the United Kingdom and around 1.4 innication work Sweden.

When fractures resulting from falls (anytype) were classified by the site of the injury, anincreased risk in older women was seen across

ining and quarry- the board: however, there was some evidencerefore omitted. that the RR varied with site of injury. In)de description: Sweden, 32% of fractures in women were to thetrators hand or wrist (excluding fingers) and for thesei1s the RR in older women was greatest at 6.39. Inand technical the United Kingdom, 40% of major fractures

in women were of the wrist (other hand injuries?ations were not classified as major fractures), andservices these also showed the greatest RR (4.85).

rators Some information on the events immediatelypreceding the fall-for example, slipped,

I Kingdom retail tripped, was pushed, vertigo-was available fortional information Sweden but there were no striking differences)up 7 (sales occu- between older and younger women.

jor sectors in the EXCESS NUMBER OF FALLSc as the classifica- If it is accepted that the increased risk among-ture. Unlike the older women of fracture from falling at work isrnited Kingdom real, then it may be useful to highlight thosestatus of the job occupational groups in whom the excess, in

rses, for example, absolute terms, is greatest. Occupational

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Figure 4 Relative risk offracture by cause in selected female occupational groups: theUnited Kingdom.

groups in each country were ranked accordingto their excess number of fractures amongwomen over 45, a statistic which depends onthe size of the occupational group and its abso-lute level of risk, as well as the relative increasein risk compared with younger women (seemethods).The total excess number of fractures after a

fall, added across all occupational groups inSweden, was 1410; thus 790o (1410/1787) ofthe total events among older women might besaid to be partly attributable to age related fac-tors. The top ranking groups accounting for theexcess were home helps, shop assistants, clean-ers, nurses, and teachers (table 4).

In the United Kingdom, the total excessmajor fractures attributable to age was 1523;this represents 67% (1523/2261, these figuresare based on those with occupational infor-mation, as the calculation of excess numberwas done separately for each three digitoccupational group) of the total events amongolder women. The top Lanking group wascleaners, among whom the RR for olderwomen (3.6) was similar to the overall valuewhen standardised for occupation (3.4); how-ever, as they constituted 11.10% of femaleemployees aged 45 years and over, the excess

number among older cleaners was particularlyhigh. Overall, cleaners contributed 15% of allfractures due to falls on the level. The otherimportant groups in this ranking were schoolteachers, care assistants, and nurses. Ratesamong three figure SOC groups ending in the

Table 4 Fractures among women due to falls: occupational groups with greatest excess number (O-E) * among womenover 45

OLcupattio?l Womnent aged 45-64

Codet DesnriptionI Evests (71) Excess O-E (nl (o)) RatellOO 000 RR

Reported under ISA, Sweden 1990-1:154 Hoime helpers 156 128 (9) 371 5.6333 Shop assistants 128 115 (8) 288 10.1932 Cleaners 130 97 (7) 305 3.9249 Clerical and related work nec 94 76 (5) 148 5.2107 Assistant nurses and hospital aids 84 71 (5) 192 6.7033 Primary education teachers 82 69 (5) 351 6.4153 Children's nurses 80 58 (4) 335 3.6400 Proprietors in agriculture and forestry 75 51 (4) 684 3.1103 Registered nurses 52 47 (3) 214 11.1913 Kitchen and restaurant assistants 60 45 (3) 227 4.1241 Secretaries, stenographers 47 39 (3) 167 5.6036 Nursery education and recreational activities

teachers 43 32 (2) 378 4.0232 Financial managers, accountants 38 30 (2) 173 4.9039 Educational workers nec 35 28 (2) 403 5.2

Total 1104 886 (63)

Reported under RIDDOR, United Kingdom 1991-3: major fractures only:958 Cleaners, domestics 414 285 (19) 124 3.2233 + 234 Secondary, primary, and nursery education teachers 167 98 (6) 220 2.2644 Care assistants, attendants 124 93 (6) 139 4.0340 Nurses 103 74 (5) 88 3.6430 Clerks nec 102 72 (5) 70 3.4620 Chefs, cooks 67 55 (4) 131 5.8459 Other secretarial, typist nec 63 53 (3) 38 6.1953 Counterhands, catering assistants 94 51 (3) 123 2.2952 Kitchenporters,hands 64 51 (3) 192 4.7919 Other labourers in making 91 49 (3) 2055 2.2659 Other childcare and related nec 47 39 (3) 115 6.0293 Social workers, probation officer 42 30 (2) 170 3.5652 Educational assistants 35 25 (2) 223 3.5640 Assistant nurses, nursing auxiliaries 46 25 (2) 79 2.1

Total 1459 1000 (66)* See text for definition of excess number.t Swedish occupational classification (NYK) or United Kingdom standard occupational classification as appropriate.nec = Not elsewhere classified.t Percentages are of the toal excess for each country.

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digit 9 may be particularly unreliable: in theorythese are jobs which do not belong in any of themore specific categories in the same field (notelsewhere classified). However these categoriesmay have been overused in coding RIDDORdata (numerator data) due to lack of detail.Overall, the groups selected are similar to Swe-den with the exception of shop assistants, whowere not included in the United Kingdomoccupational analysis.

DiscussionRates of injuries resulting from falls at workamong women in two countries, which havedifferent reporting systems, have been pre-sented. Although the underlying rates in thetwo countries are quite different, as expected,there are striking similarities in the age trends.Both showed an increased risk of injuries asso-ciated with falling at work among older womenwhich was not matched in magnitude either forother types of accidents in women or falls inmen; the increase was more notable whenattention was restricted to fall accidents result-ing in fractures, and became higher still whenrestricted to major fractures in the UnitedKingdom. There was a higher increase for fallson the level than for falls from a height.

In each country, the overall increase in therates of fractures remained after adjusting fordifferences in occupation (as measured by thethree digit code of the national classificationsystems) between older and younger women.Furthermore, the increase was seen in almostall three digit occupational groups.

REPORTING BIASThese analyses suggest that the excess associ-ated with falls is not wholly explained by agreater willingness among older women toreport accidents, for if this were the case, thereshould be a similar excess due to other causes.(A small excess for other causes was seen inolder Swedish women but no excess at all in theUnited Kingdom women.) It might be argued,however, that reporting levels vary with thetype of injury, which in turn may be related tothe type of accident; however it is a reasonableconjecture that for a specific type of injury-forexample, fracture-the level ofreporting wouldnot be influenced by the direct cause of injuryor by age. As the difference in RRs betweenfalls (high RRs), and other causes (low RRs)was maintained when the analysis was confinedto fractures, reporting bias does not seem alikely explanation for these results. Also, thesimilarity of the results from two countries,which might be expected to have different atti-tudes to reporting, suggests that the age trendis real.

WORK RELATED CAUSESIn reviewing the literature, Laflamme andMenckel3 considered that systematic differ-ences in exposure to hazards was a plausibleexplanation for age related trends in either sex,albeit less so in comparisons within occupa-tions. In this study the excess risks for falls onthe level and falls from a height remained afterstandardizing for occupation classified by three

digit codes in each country. If it could beassumed that work conditions were uniformwithin any three digit category, then suchanalyses would have controlled for workplacehazards; hence the excess could not beattributable to them alone. Of course such uni-formity is unlikely-for example, cleaners canbe employed in a wide range of premises andwith different hours of work. The possibilitythat older women carried out different tasksand were exposed to more hazards thanyounger women with the same job title cannottherefore be excluded, in which case theseanalyses have not completely controlled forconfounding by occupation.However, an increased risk was found in

practically all occupations; to explain this interms ofwork factors, it is necessary to hypoth-esise a general trend in employment wherebyolder women find themselves doing the morehazardous tasks in each case in each country.(Hazard prone activities could include stand-ing rather than sitting.) The opposite case, thatolder workers are given less physically demand-ing tasks, seems equally plausible. In theabsence of more information, these argumentsmust remain conjectures. An alternative expla-nation is that older women are as likely asyounger women to be exposed to hazards, butthat factors associated with age make themmore vulnerable to injury. Even if this is true,workplace factors may be important in deter-mining why the excess is greater in somegroups than in others.

RISK OF FALL AND RISK OF FRACTUREPostmenopausal women have an increased riskof osteoporosis and of fracture. The presentresults on fractures at work are consistent withthis knowledge although most evidence hasbeen from studies of much older women.Whether there is also an increased risk offalling (as opposed to fracturing having firstfallen) is not clear from these data. Analysesfrom the two countries of fall accidents whichdid not result in a fracture were carried out(data not shown); these showed an increasedrisk in older women although the gradientswere less strong than for fractures only (RRs forfalls on level in Sweden and the UnitedKingdom were 2.28 and 1.99 respectively).However, although we have argued that differ-ential reporting by age is unlikely to account forthe fracture gradient, this seems more likely forother, lesser injuries. Older workers may takemore time offwork to recover, so increasing thechances that the accident will be reported. Onthe other hand, an increased risk of falling issupported by a study7 which showed a dramaticdecline in muscle strength around the time ofthe menopause.Laflamme and Menckel3 argued that age

trends in occupational risk would depend onthe extent to which job experience could com-pensate for decline in physiological capacity,and that this would itself depend on the natureof the job. This theory assumes a continuity inemployment whereby older workers are more

experienced, and this may not necessarily betrue for women. Giniger and colleagues8

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suggested that older workers might be moreprone to accidents preventable by rapidresponse than they are to those preventable byjudgement. Falls on the level, which are oftenthe result of slipping or tripping, would seem tobelong to the rapid response category. In thisstudy, there was a small increase in risk of fallson the level among older men compared withyounger men in Sweden but not in the UnitedKingdom.Work is underway in both countries to

consider the question of cause. In Sweden,where full textual descriptions of the eventsleading up to the accidents have been recordedby ISA since 1994, preliminary evidence9 sug-gests that there is no difference in the distribu-tion of these events among older and youngerwomen. If correct, this would imply thatgeneral prevention strategies are appropriatebut need to be intensified in older groups, par-ticularly in the occupational sectors alreadyhighlighted.

The United Kingdom part ofthis study was partly funded by theUnited Kingdom Health and Safety Executive. Any opinions orconclusions expressed in this paper are those of the authorsalone and do not necessarily reflect Health and Safety Executivepolicy.

Appendix 1: Major injuries defined underRIDDOR 1985

(a) Fractures of the skull, spine, pelvis;(b) Fractures of any bone:* In the arm or wrist, but not a bone in the

hand, or* In the leg or ankle, but not a bone in the

foot(collar bones and ribs also excluded);

(c) Amputation of:* A hand or foot or* A finger, thumb, or toe or any part thereof

if the joint or boneis completely severed;

(d) Loss of sight of an eye or a penetratinginjury to the eye, or a chemical or hot metalburn to an eye;

(e) Either injury (including burns) requiringimmediate medical treatment, or loss ofconsciousness, resulting in either case from anyelectric shock from any electrical circuit orequipment whether or not due to directcontact;(f) Loss of consciousness resulting from lack ofoxygen;(g) Decompression sickness (unless sufferingfrom an operation to which the Diving Opera-tions at Work Regulations 1981 (a) apply);(h) Either acute illness requiring medical treat-ment, or loss of consciousness, resulting ineither case from the absorption of any sub-stance by inhalation, ingestion, or through theskin;(i) Acute illness requiring medical treatmentwhere there is reason to believe that thisresulted from exposure to a pathogen orinfected material;(j) Any other injury which results in the personinjured being admitted immediately into hospi-tal for more than 24 hours.

1 Her Majesty's Stationery Office. Health and safety statistics1994195. London: Her Majesty's Stationery Office, HSEBooks, 1995.

2 Leamon TB, Murphy PL. Occupational slips and falls: morethan a trivial problem. Ergonomics 1995;38:487-98.

3 Laflamme L, Menckel E. Aging and occupational accidents.A review of the literature of the last three decades. SafetyScience 1995;21:145-61.

4 Agnew J, Suruda AJ. Age and fatal work-related falls. HumFactors 1993;35:731-6.

5 Stevens, G. Workplace injury: a view from HSE's trailer tothe 1990 labour force survey. Employment Gazette 1992;100:621-38.

6 Ministry of Health and Social Affairs. Work injury insurancein Sweden. Stockholm: Ministry of Health and SocialAffairs, International Secretariat, 1982.

7 Phillips SK, Rook KM, Siddle NC, Bruce SA, Woledge RC.Muscle weakness in women occurs at an earlier age than inmen, but strength is preserved by hormone replacementtherapy. Clin Sci 1993;84:95-8.

8 Giniger S, Dispenzieri A, Eisenberg J. Age, experience andperformance on speed and skill in an applied setting. YApplPsychol 1983;68:469-75.

9 Kemmlert K, Lundholm L. Slips, trips and falls in differentwork groups with reference to age [abstract]. "Work over 45"Conference. Stockholm: Swedish National Board of Occu-pational Safety and Health, Sept 1996.

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