- Email: [email protected]
Health outcomes of adults 3 months after injury
Injury, Int. J. Care Injured (2007) 38, 19—26
www.elsevier.com/locate/injury
Health outcomes of adults 3 months after injury Leanne M. Aitken a,b,*, Tamzyn M. Davey c, Jane Ambrose d, Luke B. Connelly e,f, Cheryl Swanson e, Nicholas Bellamy e a
Research Centre for Clinical Practice Innovation, Griffith University, Nathan, Queensland, Australia Nursing Practice Development Unit, Building 18, Princess Alexandra Hospital, Ipswich Road, Woolloongabba, Queensland 4102, Australia c Queensland Trauma Registry, CONROD, The University of Queensland, Herston, Queensland, Australia d Pfizer, 38-42 Wharf Road, West Ryde, New South Wales 2114, Australia e CONROD, The University of Queensland, Herston, Queensland, Australia f Australian Centre for Economic Research on Health (ACERH UQ), The University of Queensland, Herston, Queensland, Australia b
Accepted 23 May 2006
KEYWORDS Health related quality of life; Health outcomes; Trauma
Summary Background: Injury is a leading cause of preventable mortality and morbidity in Australia and the world. Despite this there is little research examining the health related quality of life of adults following general trauma. Methods: A prospective cohort design was used to study adults who presented to hospital following injury. Data regarding injury and demographic details was collected through the routine operation of the Queensland Trauma Registry (QTR). In addition, the short form 36 (SF-36) was mailed to patients approximately 3 months following injury. Results: Participants included 339 injured patients who were hospitalised for 24 h in March—June 2003. A secondary group of 145 patients completed the SF-36, but did not have QTR data collected due to hospitalisation being <24 h. Both groups of participants reported significantly lower scores on all subscales of the SF-36 when compared to Australian norms. Conclusions: Health related quality of life of injured survivors is markedly reduced 3 months after injury. Ongoing treatment and support is necessary to improve these health outcomes. # 2006 Elsevier Ltd. All rights reserved.
Introduction * Corresponding author. Tel.: +61 7 3240 7256; fax: +61 7 3240 7356. E-mail address: [email protected] (L.M. Aitken).
Injury represents one of the major contributors to the public health burden in Australia. According to the Australian Institute of Health and Welfare, 6.8%
0020–1383/$ — see front matter # 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.injury.2006.05.020
20 of all separations from public, private and psychiatric hospitals in Australia in the 2001/2002 financial year were due to injury (including poisonings).2 This burden remains similar to that reported several years earlier in relation to the 1999/2000 financial year.14 In terms of expenditure, health care costs related to injury and poisoning accounted for 8.2% of the total allocated health expenditure in Australia in 2001/ 2002.2 Despite this burden, there is limited literature on the long-term outcomes of injury, including health related quality of life (HRQoL). HRQoL has a variety of descriptions, but generally it includes ‘the dimensions of physical functioning, social functioning, role functioning, mental health and general health perceptions’.40 These dimensions are effectively measured using the SF-36 instrument.8,38 HRQoL represents one aspect of the broader concept of quality of life. The measurement of HRQoL provides a useful method of assessing the outcomes of health interventions. It can also assist health workers in the identification of key areas to target in planning and monitoring different treatment options. Given that injury is a leading cause of preventable mortality and morbidity in Australia and the world and a major cost to the health system,3,5,25,31 the lack of research in this field is surprising. There has been minimal research in Australia examining the HRQoL of adults following injury, however there has been two series of work from the USA, one in general trauma patients and one in specific subgroups of trauma patients. Holbrook et al. identified reduced function up to 18 months post-injury, with function being worse in women when compared to men.15—18 Similarly, MacKenzie et al. identified poorer health across most dimensions measured by the SF-36 1 year posthead injury and poor functional outcomes up to 7 years post-severe lower limb trauma.22,24 This study was consequently developed to determine the HRQoL of adults 3 months post-injury. These HRQoL scores were then compared to noninjured Australian adults of the same age to determine whether the reported HRQoL was similar to the general population, suggesting the impact of injury was experienced for less than 3 months, or whether HRQoL was lower than the general population, suggesting the impact of injury persisted beyond 3 months. This study is making the assumption that the injured population did not differ from the general population prior to their injury.
Materials and methods A prospective cohort design was used to study people who were admitted to 1 of the 12 adult Queens-
L.M. Aitken et al. land Trauma Registry (QTR) hospitals for the treatment of injury and who granted consent for follow-up post-discharge. The sample reported in this manuscript was limited to those people who met the following criteria: aged 14 years or older at the time of injury; coded in a category between S00 and S99 or T00 and T78 (injuries and poisonings) using the International Classification of Diseases, version 10, Australian Modification (ICD10-AM). Study participants were then categorised into one of two groups: admitted to hospital for 24 h for definitive treatment of specified injury: this group met the criteria for inclusion on the QTR and therefore had information available regarding their injury and the treatment of that injury, these participants formed the Primary Study Group; discharged directly from the emergency department or admitted to hospital for <24 h: this group of participants were those who were initially expected to be admitted to hospital for 24 h, and so were enrolled in the study, but subsequently were discharged early. As a result they were not entered on the QTR, only had SF-36 data collected and formed the Secondary Study Group. To determine eligibility for inclusion in the study, patients’ health records were reviewed and cases were excluded if, in the opinion of the Trauma Registry Nurse Coordinator, the primary reason for the admission of a patient exceeding 24 h was for medical, social or psychiatric reasons, rather than primarily for treatment of the injury. For example, if the reason for admission was to treat the patient’s chronic heart failure, even if a minor injury had caused the patient to present to hospital, then the patient was excluded from the study. If the reason for admission was a combination of trauma and other reasons the patient was included in the study. Cases were also excluded if the patient was admitted for more than 24 h for elective surgical treatment of an injury or for medical complications or pathological injuries (without an associated reasonable force resulting in the injury). Patients who met the criteria for the study were approached for consent during their hospitalisation for injury between March and June 2003. Those patients who had consented to involvement in the study received a package in early August 2003. This package included a questionnaire containing the SF36 and an additional 13 demographic questions and a cover letter explaining the purpose of the study.
Health outcomes of adults 3 months after injury Demographic questions related to age, sex, indigenous and marital status, employment, education and health insurance status. In order to improve the response rate a four-step mail out process was used. This process consisted of the original postal questionnaire, followed by a reminder letter sent to all non-respondents approximately 3 weeks after posting the survey. After 6 weeks a copy of the original questionnaire was resent, and a final reminder was sent 2 weeks after the second questionnaire was posted. This study used the Australian and New Zealand version of the SF-36 (version 1) to measure the functional health status and well being of adults following their injury. The short form 36 (SF-36) is a 36 item self-administered instrument that was designed to measure HRQoL in persons 14 years of age and older.38 The SF-36 examines concepts of limitation due to health problems in the following areas: (1) physical functioning; (2) social functioning; (3) physical role (4) bodily pain; (5) mental health; (6) emotional role; (7) vitality; (8) general health. The SF-36 has been shown to have good reliability and validity in a variety of contexts both within Australia and elsewhere.6,10,12,21,22,25,26,30,34—39 In addition to the individual subscales two summary scores, the physical component summary (PCS) and mental component summary (MCS) scores were calculated using data from each of the relevant scales within the SF-36. The aim of this process was to produce meaningful summary scores without significant loss of information. Data that were collected as part of the routine operation of the QTR for the cases hospitalised for 24 h included date of birth, sex, date of injury, external cause of injury, hospital length of stay, ICU length of stay, injury description coded using the abbreviated injury scale (AIS) 1990, and injury severity score (ISS), calculated from the AIS. ISS is an interval scale which extends from 1 to 75 and incorporates the three highest scoring regions from the AIS in an attempt to quantify injuries. This study was approved by each of the Human Research Ethics Committees of the relevant hospitals in accordance with the National Health and Medical Research Council’s Guidelines. All patients who participated in the study provided an informed consent to be contacted after discharge from hospital for the purposes of research. Further consent was implied by their return of the questionnaire. Descriptive data is presented to describe the study sample. The SF-36 scores for study respondents were compared with those of the Australian norms using z-statistics. Australian normative data for SF-36 scores were obtained from a subsample of the National Health Survey collected by the
21 Australian Bureau of Statistics and included 18,800 adult residents of private dwellings.1 Multivariate analysis was performed to determine the effect of factors on the outcome of physical component summary (PCS). One-way ANOVA for categorical variables or simple linear regression for continuous variables, was used in univariate analyses of PCS score to identify potential effects for inclusion in a multivariate model. A multivariate ANCOVA was then applied to examine the partial effects of the covariates and factors that were significant with p < 0.05 in the univariate analyses. The model building process involved a step-by-step omission of non-significant effects ( p > 0.05). Unless otherwise specified, data was considered statistically significant at the five percent level. SAS version 8# (1999—2001, SAS Institute Inc., Cary, NC, USA) was used to conduct descriptive and comparative analyses, while Stata/SE 9.1# (2005, StatCorp LP, Texas, USA) and SPSS Release 13.0# (2004, SPSS Inc., Chicago, Il, USA) were used to conduct the multivariate analyses.
Results Initially 843 potential participants consented to be contacted regarding participation in the study (Fig. 1). Of the 843 consenting patients, 286 (33.9%) patients did not respond, while a further 58 (6.9%) questionnaires were returned as ‘unknown at that address’. Eleven potential participants were ineligible including seven patients who had died since hospital admission, one patient who had left the country, four patients who declined to participate and three patients who were unable to participate. Of the remaining 484 participants that returned their questionnaires, 145 (30.0%) participants were hospitalised for less than 24 h and are not considered in the main cohort for this study, but do form a Secondary Study Group for comparison of SF-36 data to the Australian norms. The remaining 339 participants met the criteria for inclusion in the Primary Study Group reported here. Comparison of the Primary Study Group to the 3367 patients entered onto the QTR during the enrolment period who met the study inclusion criteria identified few differences. Patients who participated were slightly younger than the other eligible QTR patients (48.8 19.6 years versus 48.1 24.0 years; p = 0.003), although this age difference is unlikely to hold any clinical significance. Patients who participated had a similar ISS to the other eligible QTR patients (7.8 6.2 years versus 8.9 8.6 years; p = 0.102).
22
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Figure 1
Summary of participant response.
With regard to the Primary Study Group, completed questionnaires were received from 210 (62.0%) males and 127 (37.5%) females (data were not provided by two participants). The mean age of participants was 48.8 (S.D. = 19.6) years. Participants were relatively evenly spread across the age groups corresponding to those used in the Australian National Health Survey from which the Australian norms for the SF-36 have been obtained. There were 18% of participants in the 25—34-year age group, 23% in the 45—54-year age group and 11— 12% in all other age groups. The injury severity score for participants in the Primary Study Group ranged from 1 to 50, with a mean of 7.8 (S.D. = 6.2). Twenty-two participants
were considered to have experienced major injury (ISS 16), while 312 experienced minor injury (ISS < 16). The external cause of these injuries was predominantly falls (39%) and road traffic accidents (17%), while fractures (67%) and open wounds (6%) of the limbs constituted the greatest number of injuries. Comparisons have been made between the study participants in the Primary Study Group and Australian norms for all subscales of the SF-36 except the reported health transition subscale for which there are no Australian norms published. Mean subscale scores for participants in this study were statistically significantly lower than the Australian norm mean subscale scores for every subscale as well as the two summary scores (Fig. 2). This confirms that adults who have sustained an injury that required hospitalisation for more than 24 h have a reduced HRQoL, when compared to the Australian norms, 3 months after hospitalisation. The same pattern, with participants’ scores being less than Australian norms, continued when the mean scores for each subscale for male and female participants were considered. The potential existed for Primary Study Group participants’ scores to vary from Australian norms as a result of different age distributions between the study sample and the Australian population. Therefore, the mean scores for study participants versus Australian norms broken down by age group were analysed for each subscale. In general, younger study participants’ scores were statistically lower than Australian norms for the majority of subscales, as well as the two summary scores, in the majority of age groups up to 64 years of age (Table 1). However from 65 years of age onwards the SF-36 scores for the participants in the Primary Study Group were frequently not statistically lower than the Australian norms. This pattern was particularly evident in the general health, mental health and vitality subscales. Further analysis investigated the impact of relevant factors on the PCS score of the SF-36. Factors considered for their possible effect on PCS were:
Figure 2 Sample means for both the Primary (hospitalised for 24 h, n = 337) and Secondary Study Groups (hospitalised for <24 h, n = 130) compared with Australian norms.
66.5 NS 45.3 NS 62.5 NS 64.0 * 72.2 NS 54.3 NS 54.1 * 67.5 NS 40.7 NS 46.8 * 52.1 26.2# 46.6# 54.3# 57.4# 48.1# 52.7 * 61.2 NS 37.6# 41.6 * 43.7 22.5# 43.3# 53.7# 65.9# 50.5# 47.8# 56.1 * 33.9# 45.0# 59.3 31.9# 50.3# 58.6# 67.1# 54.3# 55.1# 64.6 * 38.5# 45.2#
44.7 30.7# 50.6# 56.0# 61.4# 44.8# 45.1# 61.1# 35.2# 42.9#
# #
F
70.4 49 48.9# 25# # 58.3 37.7# 65.6# 37.5# * 68.1 53.6# # 55.4 37.3# # 55.1 46.9# 71.6 NS 59.8# 43.6# 37.6# * 45.2 36.0#
# #
F
68.2 53.5# 61.9 NS 55.7# 64.5 * 46.4# 60.5# 70.7 NS 43.6# 41.6 NS
#
M
63.4 39.2# 60.6# 63.0# 66.0# 56.5# 52.2# 70.9 * 40.3# 45.8 *
#
F
71.2 50 46.9# 35 * 66.6# 60.0 NS 60.3# 50# 64.6# 68.0 NS 57.3# 41.0# 59.7# 50.8 * 68.6 * 66.9 NS 44.9# 36.6 * 43.8# 44.1 NS
#
M
*
F
55.7 34.7 * 54.4 * 58.7 * 65.4 * 51.8 * 53.5 * 64.8 * 38.7 * 44.6 * Physical functioning Role-physical Role-emotional Social functioning Mental health Vitality Bodily pain General health Physical component Mental component
M
# *
Where significance is indicated in this table it refers only to the case of the sample mean being statistically significantly lower than the Australian norm. NS, not significant at the 5% level. * Significant at the 5% level. # Significant at the 1% level.
32.5# 28.4# 55.3 * 59.6 * 66.6 * 46.3 * 62.5 NS 56.0 NS 33.4 * 47.3 * 40.3 20.3# 28.8# 55.8 * 72.9 NS 53.2 NS 49.3 * 58.2 NS 33.0 * 45.2 * 35.9 15.2# 57.8 * 66.2# 70.8 NS 53.1 NS 55.8 * 64.3 NS 31.7# 48.2 NS
*
M F M
#
M M
F
Mean for 55—64 years Mean for 45—54 years Mean for 35—44 years Mean for 25—34 years Overall study mean Mean for 18—24 years SF-36 subscale
Table 1 Differences in SF-36 scores between Primary Study group and Australian norms for each age group
Mean for 65—74 years
#
Mean for 75+ years
F
Health outcomes of adults 3 months after injury
23 ISS, LOS, age, sex, whether or not the patient was in a tertiary hospital, private health insurance, external cause of injury, the location of the injury on the body and the mental component summary score (MCS). Factors significant in the univariate analysis or one-way ANOVA included ISS ( p < 0.001), LOS ( p < 0.001), age ( p < 0.001), sex ( p = 0.008), external cause ( p < 0.001) and body location ( p < 0.001). Investigative analysis indicated that LOS and ISS should be log-transformed. Sex and external cause of injury were omitted during the model building process as they failed to reach significance in the multivariate model; further examination of these two factors indicated confounding of sex with age and external cause with both age and ln_ISS. In the final model, ln_ISS, ln_LOS and age were all found to have a significantly negative impact on PCS (Table 2). The global test for body location also indicated a significant effect on PCS, and further investigation identified injuries to the head/neck/face, as well as abdomen, had significantly better adjusted mean PCS compared with upper and lower limb injuries.
Relationship to norms for patients hospitalised for <24 h An additional analysis was conducted to compare those hospitalised for less than 24 h (n = 130), who formed the Secondary Study Group, with the Australian norms. The z-test showed that these participants had SF-36 subscale scores that were statistically significantly lower than the Australian norms for all subscales (Fig. 2). The pattern for the participants who were in hospital for <24 h was the same as that reported for those participants hospitalised for greater than or equal to 24 h. Differences between SF-36 scores for both the Primary and Secondary Study Groups and the Australian norms were clinically significant as well as being statistically different. Greater than a five point difference on the SF-36 physical function scale was considered to be a clinically important difference.9
Discussion This study is one of the first in Australia using the short form 36 to assess the HRQoL of individuals hospitalised as a result of injury. The short form 36, a measure of adult health and well being that has been tested and standardised for Australian use, was chosen to obtain follow-up data from a cohort of adults admitted to 1 of the 12 Queensland Trauma Registry hospitals throughout the state. Results for the present study of HRQoL of adults following an
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Table 2 Multivariate model for effect on physical component summary score (n = 302) Factor
Coefficient (95% CI)
p
Constant ln_ISS ln_LOS Age Body location–—global test Upper and lower limbs (n = 211) Head/neck/face (n = 27) Thorax (n = 19) Abdomen (n = 10) Lower back (n = 11) Pelvis (n = 14) Multiple injuries (n = 7) Body location not required (n = 3)
52.5 (48.38—56.62) 2.10 ( 3.88 to 0.32) 3.75 ( 5.29 to 2.21) 0.09 ( 0.16 to 0.03)
<0.001 0.021 <0.001 0.005 0.001
Adjusted R 2
26.9
Reference 4.94 (0.78—9.10) 4.12 ( 0.86 to 9.10) 11.45 (4.86—18.05) 5.76 ( 12.01 to 0.49) 3.14 ( 8.82 to 2.54) 1.252 ( 9.09 to 6.58) 2.988 ( 14.74 to 8.78)
0.020 0.105 0.001 0.071 0.278 0.753 0.618
ln_ISS: natural log of ISS; ln_LOS: natural log of length of stay.
injury, show support for the hypothesis that adults who have sustained an injury differ in health and well being compared with Australian norms. The sample of injured people who participated in this study were spread across all adult age groups, with slightly higher numbers in the 25—34 and 45— 54-year age groups and almost two-thirds of the sample were males. The most common causes of injury were falls and road traffic accidents. This demographic representation is not unlike the full sample recorded by the QTR, although the 45—54year age group is slightly over-represented. The participants in the present study were found to have a markedly lower HRQoL overall compared with the Australian normative population. This finding is consistent with the findings from other studies in Australia using the SF-36 to determine the HRQoL in patients who have sustained hip fractures.13,33 It is also consistent with findings in international samples of injured people who have suffered from general injury,15,16,20 traumatic brain injury,10,22,30 amputation23,24,32 and orthopaedic injuries.4,19,27—29 Worthy of note is the fact that both the small group of participants who did not spend more than 24 h in hospital (the Secondary Study Group), as well as the Primary Study Group of participants who were in hospital for 24 h or more, demonstrated markedly lower HRQoL compared with the Australian population. This finding suggests that hospitalisation for either less than 24 h or 24 h and more results in a similar reduction in HRQoL when compared to the Australian norms. The prevailing pattern of outcomes in patients following a traumatic injury, as represented by the SF-36, is one of reduction or impairment in every subscale measured by the instrument when compared with the Australian norms. This pattern gen-
erally holds for each sex, across age groups, and for age groups within each sex. The differences that occurred between sexes and age groups are generally differences of magnitude, rather than kind. Where there were exceptions to this, the scores of injured participants were generally lower than the Australian norms, but were not statistically significant. These exceptions tended to occur in psychosocial, rather than physical, subscales and generally only in the older age groups. This lack of difference in the older age groups may be a reflection of the fact that older people in the normative population also experience a reduced HRQoL. It may also reflect a difference in the type of injuries sustained by older trauma patients. As identified, age and external cause of injury were significantly associated. Generally, older patients experience less high impact injuries (such as road traffic crashes) and more low impact injuries (such as falls). This pattern of results deserves further investigation. The largest impact of injury on HRQoL appeared to be on role reductions, both physical and social, in those aged between 35 and 64 years of age, while health perceptions and mental health scores, particularly in those aged 65 years or more, appeared to be closer to Australian norms. Further, females aged less than 35 years did not report statistically lower scores (when compared to Australian norms) in the areas of role–—emotional, mental health, general health and the mental component summary score. The selective impact of injury on reduced HRQoL based on a relationship between age and sex, has not been noted by previous authors, although the importance of sex by itself has been noted.17 The impact of sex on outcome following major trauma requires further investigation.
Health outcomes of adults 3 months after injury A greater influence of injury on physical scores, rather than psychosocial scores, is also consistent with previous work. A small group of patients with open tibial fractures who had amputation or successful reconstruction of lower limbs reported scores lower than a healthy reference group in the physical functioning, role–—physical and bodily pain subscales, but no other subscales.19 This pattern was also found in a previous study of 78 traumatic amputee patients.32 Similarly, patients with pelvic fractures reported a 14% lower PCS when compared to US norms, but only a 6% lower MCS,29 while female patients with pelvic or lower extremity injury reported significantly lower scores on all subscales except mental health.27 In a group of 20 adults with unstable ankle fractures, while five subscale scores were lower than US population scores approximately 4 months after the injury, the only subscale scores that remained significantly below the normative scores by 18 months postinjury were the physical function scores.28 Although most of the published literature has concentrated on orthopaedic patients the results are comparable to those found in this study as two-thirds of the sample experienced a fracture injury. Limitations of this study include the assumption that participants were functioning well prior to injury, the low response rate and low proportion of participants with a major injury, the high proportion of participants with a fracture injury and the limited follow-up to only 3 months post injury. Participants were assumed to be functioning well prior to injury and therefore that the reduction in scores at 3 months can be attributed to the injury. Pre-injury HRQoL data has not been collected retrospectively due to the recognised limited reliability of this method of data collection resulting from the potential for recall bias.11 It is recognised that data exists to indicate that injured people have a higher incidence of pre-existing morbidity than their noninjured counterparts,7 although no method currently exists to adapt normative HRQoL data to accommodate this difference. The low response rate and small proportion of study participants (<10%) who were categorised as having experienced major injury limit the generalisability of results. It is possible that patients who did participate in the study were those who were experiencing poor HRQoL and were consequently motivated to participate in the study as a strategy to document this problem. Despite these concerns it should be noted that study participants had a similar age and ISS to the other eligible QTR patients during the enrolment period. It is possible that any differences between participants and Australian norms would be greater if
25 more seriously injured patients were included. The potential existed for the preferential impact of injury on physical, rather than psychosocial, scores to be different for those who experienced major injury, although there were insufficient major injury patients in this study to allow further analysis of this feature. A further limitation is the high proportion of study participants who experienced a fracture injury. While this represents the greatest group of injured people, it cannot be assumed that people with differing injuries, such as injuries to internal organs, experience similar reductions in HRQoL. Finally, this study only extended to an average of 3 months post-hospitalisation for injury. It would be appropriate to extend the time frame to determine the length of compromise to HRQoL. In addition, no assessment has been made of the impact of any intervention, such as rehabilitation, on HRQoL and this should be incorporated into a larger study that allows analysis of multiple interrelated factors such as age, ongoing health care interventions and pre-injury HRQoL.
Conclusions In the majority of age groups the participants in this study reported lower HRQoL in the majority of subscales measured on the SF-36 approximately 3 months post-injury. The lowest scores, when compared to Australian norms, were reported in the physical, rather than psychosocial subscales. People who were injured and were admitted to hospital for less than 24 h reported similarly reduced scores on the SF-36 when compared with Australian norms. It is evident that significant reductions in HRQoL are apparent up to 3 months after hospitalisation for injury. This suggests that people who are injured experienced considerable burden for at least 3 months post-injury. Consequently, support through this period is necessary to assist return to the optimal HRQoL possible. Such HRQoL may be less than that experienced prior to injury, but should be optimised for each individual.
Conflict of interest There are no conflicts of interest by any authors in relation to this article.
Acknowledgements The authors wish to thank Ms. Joan Hendrikz for her assistance with statistical analysis during the
26 preparation of this manuscript. The authors also wish to thank the Motor Accident Insurance Commission (Qld) for the funding provided to support this research as a component of the Queensland Trauma Plan Project.
References 1. Australian Bureau of Statistics. National Health Survey: SF-36 Population Norms, Australia Canberra: Commonwealth of Australia; 1997. 2. Australian Institute of Health and Welfare. Australia’s Health 2004 Canberra: AIHW; 2004. 3. Australian Institute of Health and Welfare and Commonwealth Department of Health and Family Services. First report on National Health Priority Areas 1996. AIHW Cat. No. PHE 1. Canberra: AIHW and DHFS; 1997. 4. Axtelius B, Soderfeldt B, Bring G. Self-assessments of general and oral health in persons with chronic whiplash-related disorders. Community Dent Health 2002;19(1):32—8. 5. Bonnie RJ, Fulco CE, Liverman CT, editors. Reducing the burden of injury–—advancing prevention and treatment. Washington, DC: National Academy Press; 1999. 6. Bono G, et al. Whiplash injuries: clinical picture and diagnostic work-up. Clin Exp Rheumatol 2000;18(2 Suppl 19):S23—8. 7. Cameron C, et al. Long-term mortality following trauma: 10year follow-up in a population-based sample of injured adults. J Trauma 2005;59(3):639—46. 8. Coons SJ, et al. A comparative review of generic quality-oflife instruments. Pharmacoeconomics 2000;17(1):13—35. 9. Dowdy D, et al. Quality of life in adult survivors of critical illness: a systematic review of the literature. Intens Care Med 2005;31:611—20. 10. Findler M, et al. The reliability and validity of the SF-36 health survey questionnaire for use with individuals with traumatic brain injury. Brain Injury 2001;15(8): 715—23. 11. Gabbe BJ, et al. Choosing outcome assessment instruments for trauma registries. Acad Emerg Med 2005;12(8):751—8. 12. Girotto JA, et al. Long-term physical impairment and functional outcomes after complex facial fractures. Plast Reconstr Surg 2001;108(2):312—27. 13. Hall SE, et al. Hip fracture outcomes: quality of life and functional status in older adults living in the community. Aust NZ J Med 2000;30(3):327—32. 14. Helps, Y, Cripps R, Harrison J. Hospital separations due to injury and poisoning, Australia 1999—2000. Injury Research and Statistics Series Number 15. AIHW Cat. No. INJCAT 48. Adelaide: Australian Institute of Health and Welfare; 2002. p. 40. 15. Holbrook TL, et al. Outcome after major trauma: discharge and 6-month follow-up results from the Trauma Recovery Project. J Trauma 1998;45(2):315—23 [discussion 323—4]. 16. Holbrook TL, et al. Outcome after major trauma: 12-month and 18-month follow-up results from the Trauma Recovery Project. J Trauma 1999;46(5):765—71 [discussion 771—3]. 17. Holbrook TL, Hoyt DB, Anderson JP. The importance of gender on outcome after major trauma: functional and psychologic outcomes in women versus men. J Trauma 2001;50(2):270—3. 18. Holbrook TL, Hoyt DB, Anderson JP. The impact of major inhospital complications on functional outcome and quality of life after trauma. J Trauma 2001;50(1):91—5.
L.M. Aitken et al. 19. Hoogendoorn JM, van der Werken C. Grade III open tibial fractures: functional outcome and quality of life in amputees versus patients with successful reconstruction. Injury 2001;32(4):329—34. 20. Inaba K, et al. Long-term outcomes after injury in the elderly. J Trauma 2003;54(3):486—91. 21. Kyes KB, Franklin G, Weaver MR. Reliability and validity of medical outcome and patient satisfaction measures among injured workers in Washington state: a pretest. Am J Ind Med 1997;31(4):427—34. 22. MacKenzie EJ, et al. Using the SF-36 for characterizing outcome after multiple trauma involving head injury. J Trauma 2002;52(3):527—34. 23. MacKenzie EJ, et al. Functional outcomes following traumarelated lower-extremity amputation. J Bone Joint Surg Am A 2004;86(8):1636—45. 24. MacKenzie EJ, et al. Long-term persistence of disability following severe lower-limb trauma. Results of a seven-year follow-up. J Bone Joint Surg Am 2005;87(8):1801—9. 25. Mathers, C, Vos, T, Stevenson, C. The burden of disease and injury in Australia. AIHW Cat. No. PHE 17. Canberra: Australian Institute of Health and Welfare; 1999. 26. McCallum J. The SF-36 in an Australian sample: validating a new, generic health status measure. Aust J Public Health 1995;19(2):160—6. 27. McCarthy ML, et al. Functional status following orthopedic trauma in young women. J Trauma 1995;39(5):828—36 [discussion 836—7]. 28. Obremskey WT, et al. Change over time of SF-36 functional outcomes for operatively treated unstable ankle fractures. J Orthop Trauma 2002;16(1):30—3. 29. Oliver CW, et al. Outcome after pelvic ring fractures: evaluation using the medical outcomes short form SF-36. Injury 1996;27(9):635—41. 30. Paniak C, et al. Sensitivity of three recent questionnaires to mild traumatic brain injury-related effects. J Head Trauma Rehabil 1999;14(3):211—9. 31. Peden M, McGee K, Krug E, editors. Injury: a leading cause of the global burden of disease, 2000. Geneva: World Health Organisation; 2002. 32. Pezzin LE, Dillingham TR, MacKenzie EJ. Rehabilitation and the long-term outcomes of persons with trauma-related amputations. Arch Phys Med Rehabil 2000;81(3):292—300. 33. Randell AG, et al. Deterioration in quality of life following hip fracture: a prospective study. Osteoporos Int 2000;11(5): 460—6. 34. Ristner G, et al. Sense of coherence and lack of control in relation to outcome after orthopaedic injuries. Injury 2000;31(10):751—6. 35. Shadbolt B, McCallum J, Singh M. Health outcomes by selfreport: validity of the SF-36 among Australian hospital patients. Qual Life Res 1997;6(4):343—52. 36. Shapiro ET, et al. The use of a generic, patient-based health assessment (SF-36) for evaluation of patients with anterior cruciate ligament injuries. Am J Sports Med 1996;24(2):196— 200. 37. Ware, JE, Snow KK, Kosinski M. SF-36 Health Survey: Manual and Interpretation Guide. Lincoln: Quality Metric Incorporated; 2000. 38. Ware Jr JE, Sherbourne CD. The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection. Med Care 1992;30(6):473—83. 39. Ware Jr JE. SF-36 health survey update. Spine 2000;25(24): 3130—9. 40. Wilson IB, Cleary PD. Linking clinical variables with healthrelated quality of life. A conceptual model of patient outcomes. JAMA 1995;273(1):59—65.
www.elsevier.com/locate/injury
Health outcomes of adults 3 months after injury Leanne M. Aitken a,b,*, Tamzyn M. Davey c, Jane Ambrose d, Luke B. Connelly e,f, Cheryl Swanson e, Nicholas Bellamy e a
Research Centre for Clinical Practice Innovation, Griffith University, Nathan, Queensland, Australia Nursing Practice Development Unit, Building 18, Princess Alexandra Hospital, Ipswich Road, Woolloongabba, Queensland 4102, Australia c Queensland Trauma Registry, CONROD, The University of Queensland, Herston, Queensland, Australia d Pfizer, 38-42 Wharf Road, West Ryde, New South Wales 2114, Australia e CONROD, The University of Queensland, Herston, Queensland, Australia f Australian Centre for Economic Research on Health (ACERH UQ), The University of Queensland, Herston, Queensland, Australia b
Accepted 23 May 2006
KEYWORDS Health related quality of life; Health outcomes; Trauma
Summary Background: Injury is a leading cause of preventable mortality and morbidity in Australia and the world. Despite this there is little research examining the health related quality of life of adults following general trauma. Methods: A prospective cohort design was used to study adults who presented to hospital following injury. Data regarding injury and demographic details was collected through the routine operation of the Queensland Trauma Registry (QTR). In addition, the short form 36 (SF-36) was mailed to patients approximately 3 months following injury. Results: Participants included 339 injured patients who were hospitalised for 24 h in March—June 2003. A secondary group of 145 patients completed the SF-36, but did not have QTR data collected due to hospitalisation being <24 h. Both groups of participants reported significantly lower scores on all subscales of the SF-36 when compared to Australian norms. Conclusions: Health related quality of life of injured survivors is markedly reduced 3 months after injury. Ongoing treatment and support is necessary to improve these health outcomes. # 2006 Elsevier Ltd. All rights reserved.
Introduction * Corresponding author. Tel.: +61 7 3240 7256; fax: +61 7 3240 7356. E-mail address: [email protected] (L.M. Aitken).
Injury represents one of the major contributors to the public health burden in Australia. According to the Australian Institute of Health and Welfare, 6.8%
0020–1383/$ — see front matter # 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.injury.2006.05.020
20 of all separations from public, private and psychiatric hospitals in Australia in the 2001/2002 financial year were due to injury (including poisonings).2 This burden remains similar to that reported several years earlier in relation to the 1999/2000 financial year.14 In terms of expenditure, health care costs related to injury and poisoning accounted for 8.2% of the total allocated health expenditure in Australia in 2001/ 2002.2 Despite this burden, there is limited literature on the long-term outcomes of injury, including health related quality of life (HRQoL). HRQoL has a variety of descriptions, but generally it includes ‘the dimensions of physical functioning, social functioning, role functioning, mental health and general health perceptions’.40 These dimensions are effectively measured using the SF-36 instrument.8,38 HRQoL represents one aspect of the broader concept of quality of life. The measurement of HRQoL provides a useful method of assessing the outcomes of health interventions. It can also assist health workers in the identification of key areas to target in planning and monitoring different treatment options. Given that injury is a leading cause of preventable mortality and morbidity in Australia and the world and a major cost to the health system,3,5,25,31 the lack of research in this field is surprising. There has been minimal research in Australia examining the HRQoL of adults following injury, however there has been two series of work from the USA, one in general trauma patients and one in specific subgroups of trauma patients. Holbrook et al. identified reduced function up to 18 months post-injury, with function being worse in women when compared to men.15—18 Similarly, MacKenzie et al. identified poorer health across most dimensions measured by the SF-36 1 year posthead injury and poor functional outcomes up to 7 years post-severe lower limb trauma.22,24 This study was consequently developed to determine the HRQoL of adults 3 months post-injury. These HRQoL scores were then compared to noninjured Australian adults of the same age to determine whether the reported HRQoL was similar to the general population, suggesting the impact of injury was experienced for less than 3 months, or whether HRQoL was lower than the general population, suggesting the impact of injury persisted beyond 3 months. This study is making the assumption that the injured population did not differ from the general population prior to their injury.
Materials and methods A prospective cohort design was used to study people who were admitted to 1 of the 12 adult Queens-
L.M. Aitken et al. land Trauma Registry (QTR) hospitals for the treatment of injury and who granted consent for follow-up post-discharge. The sample reported in this manuscript was limited to those people who met the following criteria: aged 14 years or older at the time of injury; coded in a category between S00 and S99 or T00 and T78 (injuries and poisonings) using the International Classification of Diseases, version 10, Australian Modification (ICD10-AM). Study participants were then categorised into one of two groups: admitted to hospital for 24 h for definitive treatment of specified injury: this group met the criteria for inclusion on the QTR and therefore had information available regarding their injury and the treatment of that injury, these participants formed the Primary Study Group; discharged directly from the emergency department or admitted to hospital for <24 h: this group of participants were those who were initially expected to be admitted to hospital for 24 h, and so were enrolled in the study, but subsequently were discharged early. As a result they were not entered on the QTR, only had SF-36 data collected and formed the Secondary Study Group. To determine eligibility for inclusion in the study, patients’ health records were reviewed and cases were excluded if, in the opinion of the Trauma Registry Nurse Coordinator, the primary reason for the admission of a patient exceeding 24 h was for medical, social or psychiatric reasons, rather than primarily for treatment of the injury. For example, if the reason for admission was to treat the patient’s chronic heart failure, even if a minor injury had caused the patient to present to hospital, then the patient was excluded from the study. If the reason for admission was a combination of trauma and other reasons the patient was included in the study. Cases were also excluded if the patient was admitted for more than 24 h for elective surgical treatment of an injury or for medical complications or pathological injuries (without an associated reasonable force resulting in the injury). Patients who met the criteria for the study were approached for consent during their hospitalisation for injury between March and June 2003. Those patients who had consented to involvement in the study received a package in early August 2003. This package included a questionnaire containing the SF36 and an additional 13 demographic questions and a cover letter explaining the purpose of the study.
Health outcomes of adults 3 months after injury Demographic questions related to age, sex, indigenous and marital status, employment, education and health insurance status. In order to improve the response rate a four-step mail out process was used. This process consisted of the original postal questionnaire, followed by a reminder letter sent to all non-respondents approximately 3 weeks after posting the survey. After 6 weeks a copy of the original questionnaire was resent, and a final reminder was sent 2 weeks after the second questionnaire was posted. This study used the Australian and New Zealand version of the SF-36 (version 1) to measure the functional health status and well being of adults following their injury. The short form 36 (SF-36) is a 36 item self-administered instrument that was designed to measure HRQoL in persons 14 years of age and older.38 The SF-36 examines concepts of limitation due to health problems in the following areas: (1) physical functioning; (2) social functioning; (3) physical role (4) bodily pain; (5) mental health; (6) emotional role; (7) vitality; (8) general health. The SF-36 has been shown to have good reliability and validity in a variety of contexts both within Australia and elsewhere.6,10,12,21,22,25,26,30,34—39 In addition to the individual subscales two summary scores, the physical component summary (PCS) and mental component summary (MCS) scores were calculated using data from each of the relevant scales within the SF-36. The aim of this process was to produce meaningful summary scores without significant loss of information. Data that were collected as part of the routine operation of the QTR for the cases hospitalised for 24 h included date of birth, sex, date of injury, external cause of injury, hospital length of stay, ICU length of stay, injury description coded using the abbreviated injury scale (AIS) 1990, and injury severity score (ISS), calculated from the AIS. ISS is an interval scale which extends from 1 to 75 and incorporates the three highest scoring regions from the AIS in an attempt to quantify injuries. This study was approved by each of the Human Research Ethics Committees of the relevant hospitals in accordance with the National Health and Medical Research Council’s Guidelines. All patients who participated in the study provided an informed consent to be contacted after discharge from hospital for the purposes of research. Further consent was implied by their return of the questionnaire. Descriptive data is presented to describe the study sample. The SF-36 scores for study respondents were compared with those of the Australian norms using z-statistics. Australian normative data for SF-36 scores were obtained from a subsample of the National Health Survey collected by the
21 Australian Bureau of Statistics and included 18,800 adult residents of private dwellings.1 Multivariate analysis was performed to determine the effect of factors on the outcome of physical component summary (PCS). One-way ANOVA for categorical variables or simple linear regression for continuous variables, was used in univariate analyses of PCS score to identify potential effects for inclusion in a multivariate model. A multivariate ANCOVA was then applied to examine the partial effects of the covariates and factors that were significant with p < 0.05 in the univariate analyses. The model building process involved a step-by-step omission of non-significant effects ( p > 0.05). Unless otherwise specified, data was considered statistically significant at the five percent level. SAS version 8# (1999—2001, SAS Institute Inc., Cary, NC, USA) was used to conduct descriptive and comparative analyses, while Stata/SE 9.1# (2005, StatCorp LP, Texas, USA) and SPSS Release 13.0# (2004, SPSS Inc., Chicago, Il, USA) were used to conduct the multivariate analyses.
Results Initially 843 potential participants consented to be contacted regarding participation in the study (Fig. 1). Of the 843 consenting patients, 286 (33.9%) patients did not respond, while a further 58 (6.9%) questionnaires were returned as ‘unknown at that address’. Eleven potential participants were ineligible including seven patients who had died since hospital admission, one patient who had left the country, four patients who declined to participate and three patients who were unable to participate. Of the remaining 484 participants that returned their questionnaires, 145 (30.0%) participants were hospitalised for less than 24 h and are not considered in the main cohort for this study, but do form a Secondary Study Group for comparison of SF-36 data to the Australian norms. The remaining 339 participants met the criteria for inclusion in the Primary Study Group reported here. Comparison of the Primary Study Group to the 3367 patients entered onto the QTR during the enrolment period who met the study inclusion criteria identified few differences. Patients who participated were slightly younger than the other eligible QTR patients (48.8 19.6 years versus 48.1 24.0 years; p = 0.003), although this age difference is unlikely to hold any clinical significance. Patients who participated had a similar ISS to the other eligible QTR patients (7.8 6.2 years versus 8.9 8.6 years; p = 0.102).
22
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Figure 1
Summary of participant response.
With regard to the Primary Study Group, completed questionnaires were received from 210 (62.0%) males and 127 (37.5%) females (data were not provided by two participants). The mean age of participants was 48.8 (S.D. = 19.6) years. Participants were relatively evenly spread across the age groups corresponding to those used in the Australian National Health Survey from which the Australian norms for the SF-36 have been obtained. There were 18% of participants in the 25—34-year age group, 23% in the 45—54-year age group and 11— 12% in all other age groups. The injury severity score for participants in the Primary Study Group ranged from 1 to 50, with a mean of 7.8 (S.D. = 6.2). Twenty-two participants
were considered to have experienced major injury (ISS 16), while 312 experienced minor injury (ISS < 16). The external cause of these injuries was predominantly falls (39%) and road traffic accidents (17%), while fractures (67%) and open wounds (6%) of the limbs constituted the greatest number of injuries. Comparisons have been made between the study participants in the Primary Study Group and Australian norms for all subscales of the SF-36 except the reported health transition subscale for which there are no Australian norms published. Mean subscale scores for participants in this study were statistically significantly lower than the Australian norm mean subscale scores for every subscale as well as the two summary scores (Fig. 2). This confirms that adults who have sustained an injury that required hospitalisation for more than 24 h have a reduced HRQoL, when compared to the Australian norms, 3 months after hospitalisation. The same pattern, with participants’ scores being less than Australian norms, continued when the mean scores for each subscale for male and female participants were considered. The potential existed for Primary Study Group participants’ scores to vary from Australian norms as a result of different age distributions between the study sample and the Australian population. Therefore, the mean scores for study participants versus Australian norms broken down by age group were analysed for each subscale. In general, younger study participants’ scores were statistically lower than Australian norms for the majority of subscales, as well as the two summary scores, in the majority of age groups up to 64 years of age (Table 1). However from 65 years of age onwards the SF-36 scores for the participants in the Primary Study Group were frequently not statistically lower than the Australian norms. This pattern was particularly evident in the general health, mental health and vitality subscales. Further analysis investigated the impact of relevant factors on the PCS score of the SF-36. Factors considered for their possible effect on PCS were:
Figure 2 Sample means for both the Primary (hospitalised for 24 h, n = 337) and Secondary Study Groups (hospitalised for <24 h, n = 130) compared with Australian norms.
66.5 NS 45.3 NS 62.5 NS 64.0 * 72.2 NS 54.3 NS 54.1 * 67.5 NS 40.7 NS 46.8 * 52.1 26.2# 46.6# 54.3# 57.4# 48.1# 52.7 * 61.2 NS 37.6# 41.6 * 43.7 22.5# 43.3# 53.7# 65.9# 50.5# 47.8# 56.1 * 33.9# 45.0# 59.3 31.9# 50.3# 58.6# 67.1# 54.3# 55.1# 64.6 * 38.5# 45.2#
44.7 30.7# 50.6# 56.0# 61.4# 44.8# 45.1# 61.1# 35.2# 42.9#
# #
F
70.4 49 48.9# 25# # 58.3 37.7# 65.6# 37.5# * 68.1 53.6# # 55.4 37.3# # 55.1 46.9# 71.6 NS 59.8# 43.6# 37.6# * 45.2 36.0#
# #
F
68.2 53.5# 61.9 NS 55.7# 64.5 * 46.4# 60.5# 70.7 NS 43.6# 41.6 NS
#
M
63.4 39.2# 60.6# 63.0# 66.0# 56.5# 52.2# 70.9 * 40.3# 45.8 *
#
F
71.2 50 46.9# 35 * 66.6# 60.0 NS 60.3# 50# 64.6# 68.0 NS 57.3# 41.0# 59.7# 50.8 * 68.6 * 66.9 NS 44.9# 36.6 * 43.8# 44.1 NS
#
M
*
F
55.7 34.7 * 54.4 * 58.7 * 65.4 * 51.8 * 53.5 * 64.8 * 38.7 * 44.6 * Physical functioning Role-physical Role-emotional Social functioning Mental health Vitality Bodily pain General health Physical component Mental component
M
# *
Where significance is indicated in this table it refers only to the case of the sample mean being statistically significantly lower than the Australian norm. NS, not significant at the 5% level. * Significant at the 5% level. # Significant at the 1% level.
32.5# 28.4# 55.3 * 59.6 * 66.6 * 46.3 * 62.5 NS 56.0 NS 33.4 * 47.3 * 40.3 20.3# 28.8# 55.8 * 72.9 NS 53.2 NS 49.3 * 58.2 NS 33.0 * 45.2 * 35.9 15.2# 57.8 * 66.2# 70.8 NS 53.1 NS 55.8 * 64.3 NS 31.7# 48.2 NS
*
M F M
#
M M
F
Mean for 55—64 years Mean for 45—54 years Mean for 35—44 years Mean for 25—34 years Overall study mean Mean for 18—24 years SF-36 subscale
Table 1 Differences in SF-36 scores between Primary Study group and Australian norms for each age group
Mean for 65—74 years
#
Mean for 75+ years
F
Health outcomes of adults 3 months after injury
23 ISS, LOS, age, sex, whether or not the patient was in a tertiary hospital, private health insurance, external cause of injury, the location of the injury on the body and the mental component summary score (MCS). Factors significant in the univariate analysis or one-way ANOVA included ISS ( p < 0.001), LOS ( p < 0.001), age ( p < 0.001), sex ( p = 0.008), external cause ( p < 0.001) and body location ( p < 0.001). Investigative analysis indicated that LOS and ISS should be log-transformed. Sex and external cause of injury were omitted during the model building process as they failed to reach significance in the multivariate model; further examination of these two factors indicated confounding of sex with age and external cause with both age and ln_ISS. In the final model, ln_ISS, ln_LOS and age were all found to have a significantly negative impact on PCS (Table 2). The global test for body location also indicated a significant effect on PCS, and further investigation identified injuries to the head/neck/face, as well as abdomen, had significantly better adjusted mean PCS compared with upper and lower limb injuries.
Relationship to norms for patients hospitalised for <24 h An additional analysis was conducted to compare those hospitalised for less than 24 h (n = 130), who formed the Secondary Study Group, with the Australian norms. The z-test showed that these participants had SF-36 subscale scores that were statistically significantly lower than the Australian norms for all subscales (Fig. 2). The pattern for the participants who were in hospital for <24 h was the same as that reported for those participants hospitalised for greater than or equal to 24 h. Differences between SF-36 scores for both the Primary and Secondary Study Groups and the Australian norms were clinically significant as well as being statistically different. Greater than a five point difference on the SF-36 physical function scale was considered to be a clinically important difference.9
Discussion This study is one of the first in Australia using the short form 36 to assess the HRQoL of individuals hospitalised as a result of injury. The short form 36, a measure of adult health and well being that has been tested and standardised for Australian use, was chosen to obtain follow-up data from a cohort of adults admitted to 1 of the 12 Queensland Trauma Registry hospitals throughout the state. Results for the present study of HRQoL of adults following an
24
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Table 2 Multivariate model for effect on physical component summary score (n = 302) Factor
Coefficient (95% CI)
p
Constant ln_ISS ln_LOS Age Body location–—global test Upper and lower limbs (n = 211) Head/neck/face (n = 27) Thorax (n = 19) Abdomen (n = 10) Lower back (n = 11) Pelvis (n = 14) Multiple injuries (n = 7) Body location not required (n = 3)
52.5 (48.38—56.62) 2.10 ( 3.88 to 0.32) 3.75 ( 5.29 to 2.21) 0.09 ( 0.16 to 0.03)
<0.001 0.021 <0.001 0.005 0.001
Adjusted R 2
26.9
Reference 4.94 (0.78—9.10) 4.12 ( 0.86 to 9.10) 11.45 (4.86—18.05) 5.76 ( 12.01 to 0.49) 3.14 ( 8.82 to 2.54) 1.252 ( 9.09 to 6.58) 2.988 ( 14.74 to 8.78)
0.020 0.105 0.001 0.071 0.278 0.753 0.618
ln_ISS: natural log of ISS; ln_LOS: natural log of length of stay.
injury, show support for the hypothesis that adults who have sustained an injury differ in health and well being compared with Australian norms. The sample of injured people who participated in this study were spread across all adult age groups, with slightly higher numbers in the 25—34 and 45— 54-year age groups and almost two-thirds of the sample were males. The most common causes of injury were falls and road traffic accidents. This demographic representation is not unlike the full sample recorded by the QTR, although the 45—54year age group is slightly over-represented. The participants in the present study were found to have a markedly lower HRQoL overall compared with the Australian normative population. This finding is consistent with the findings from other studies in Australia using the SF-36 to determine the HRQoL in patients who have sustained hip fractures.13,33 It is also consistent with findings in international samples of injured people who have suffered from general injury,15,16,20 traumatic brain injury,10,22,30 amputation23,24,32 and orthopaedic injuries.4,19,27—29 Worthy of note is the fact that both the small group of participants who did not spend more than 24 h in hospital (the Secondary Study Group), as well as the Primary Study Group of participants who were in hospital for 24 h or more, demonstrated markedly lower HRQoL compared with the Australian population. This finding suggests that hospitalisation for either less than 24 h or 24 h and more results in a similar reduction in HRQoL when compared to the Australian norms. The prevailing pattern of outcomes in patients following a traumatic injury, as represented by the SF-36, is one of reduction or impairment in every subscale measured by the instrument when compared with the Australian norms. This pattern gen-
erally holds for each sex, across age groups, and for age groups within each sex. The differences that occurred between sexes and age groups are generally differences of magnitude, rather than kind. Where there were exceptions to this, the scores of injured participants were generally lower than the Australian norms, but were not statistically significant. These exceptions tended to occur in psychosocial, rather than physical, subscales and generally only in the older age groups. This lack of difference in the older age groups may be a reflection of the fact that older people in the normative population also experience a reduced HRQoL. It may also reflect a difference in the type of injuries sustained by older trauma patients. As identified, age and external cause of injury were significantly associated. Generally, older patients experience less high impact injuries (such as road traffic crashes) and more low impact injuries (such as falls). This pattern of results deserves further investigation. The largest impact of injury on HRQoL appeared to be on role reductions, both physical and social, in those aged between 35 and 64 years of age, while health perceptions and mental health scores, particularly in those aged 65 years or more, appeared to be closer to Australian norms. Further, females aged less than 35 years did not report statistically lower scores (when compared to Australian norms) in the areas of role–—emotional, mental health, general health and the mental component summary score. The selective impact of injury on reduced HRQoL based on a relationship between age and sex, has not been noted by previous authors, although the importance of sex by itself has been noted.17 The impact of sex on outcome following major trauma requires further investigation.
Health outcomes of adults 3 months after injury A greater influence of injury on physical scores, rather than psychosocial scores, is also consistent with previous work. A small group of patients with open tibial fractures who had amputation or successful reconstruction of lower limbs reported scores lower than a healthy reference group in the physical functioning, role–—physical and bodily pain subscales, but no other subscales.19 This pattern was also found in a previous study of 78 traumatic amputee patients.32 Similarly, patients with pelvic fractures reported a 14% lower PCS when compared to US norms, but only a 6% lower MCS,29 while female patients with pelvic or lower extremity injury reported significantly lower scores on all subscales except mental health.27 In a group of 20 adults with unstable ankle fractures, while five subscale scores were lower than US population scores approximately 4 months after the injury, the only subscale scores that remained significantly below the normative scores by 18 months postinjury were the physical function scores.28 Although most of the published literature has concentrated on orthopaedic patients the results are comparable to those found in this study as two-thirds of the sample experienced a fracture injury. Limitations of this study include the assumption that participants were functioning well prior to injury, the low response rate and low proportion of participants with a major injury, the high proportion of participants with a fracture injury and the limited follow-up to only 3 months post injury. Participants were assumed to be functioning well prior to injury and therefore that the reduction in scores at 3 months can be attributed to the injury. Pre-injury HRQoL data has not been collected retrospectively due to the recognised limited reliability of this method of data collection resulting from the potential for recall bias.11 It is recognised that data exists to indicate that injured people have a higher incidence of pre-existing morbidity than their noninjured counterparts,7 although no method currently exists to adapt normative HRQoL data to accommodate this difference. The low response rate and small proportion of study participants (<10%) who were categorised as having experienced major injury limit the generalisability of results. It is possible that patients who did participate in the study were those who were experiencing poor HRQoL and were consequently motivated to participate in the study as a strategy to document this problem. Despite these concerns it should be noted that study participants had a similar age and ISS to the other eligible QTR patients during the enrolment period. It is possible that any differences between participants and Australian norms would be greater if
25 more seriously injured patients were included. The potential existed for the preferential impact of injury on physical, rather than psychosocial, scores to be different for those who experienced major injury, although there were insufficient major injury patients in this study to allow further analysis of this feature. A further limitation is the high proportion of study participants who experienced a fracture injury. While this represents the greatest group of injured people, it cannot be assumed that people with differing injuries, such as injuries to internal organs, experience similar reductions in HRQoL. Finally, this study only extended to an average of 3 months post-hospitalisation for injury. It would be appropriate to extend the time frame to determine the length of compromise to HRQoL. In addition, no assessment has been made of the impact of any intervention, such as rehabilitation, on HRQoL and this should be incorporated into a larger study that allows analysis of multiple interrelated factors such as age, ongoing health care interventions and pre-injury HRQoL.
Conclusions In the majority of age groups the participants in this study reported lower HRQoL in the majority of subscales measured on the SF-36 approximately 3 months post-injury. The lowest scores, when compared to Australian norms, were reported in the physical, rather than psychosocial subscales. People who were injured and were admitted to hospital for less than 24 h reported similarly reduced scores on the SF-36 when compared with Australian norms. It is evident that significant reductions in HRQoL are apparent up to 3 months after hospitalisation for injury. This suggests that people who are injured experienced considerable burden for at least 3 months post-injury. Consequently, support through this period is necessary to assist return to the optimal HRQoL possible. Such HRQoL may be less than that experienced prior to injury, but should be optimised for each individual.
Conflict of interest There are no conflicts of interest by any authors in relation to this article.
Acknowledgements The authors wish to thank Ms. Joan Hendrikz for her assistance with statistical analysis during the
26 preparation of this manuscript. The authors also wish to thank the Motor Accident Insurance Commission (Qld) for the funding provided to support this research as a component of the Queensland Trauma Plan Project.
References 1. Australian Bureau of Statistics. National Health Survey: SF-36 Population Norms, Australia Canberra: Commonwealth of Australia; 1997. 2. Australian Institute of Health and Welfare. Australia’s Health 2004 Canberra: AIHW; 2004. 3. Australian Institute of Health and Welfare and Commonwealth Department of Health and Family Services. First report on National Health Priority Areas 1996. AIHW Cat. No. PHE 1. Canberra: AIHW and DHFS; 1997. 4. Axtelius B, Soderfeldt B, Bring G. Self-assessments of general and oral health in persons with chronic whiplash-related disorders. Community Dent Health 2002;19(1):32—8. 5. Bonnie RJ, Fulco CE, Liverman CT, editors. Reducing the burden of injury–—advancing prevention and treatment. Washington, DC: National Academy Press; 1999. 6. Bono G, et al. Whiplash injuries: clinical picture and diagnostic work-up. Clin Exp Rheumatol 2000;18(2 Suppl 19):S23—8. 7. Cameron C, et al. Long-term mortality following trauma: 10year follow-up in a population-based sample of injured adults. J Trauma 2005;59(3):639—46. 8. Coons SJ, et al. A comparative review of generic quality-oflife instruments. Pharmacoeconomics 2000;17(1):13—35. 9. Dowdy D, et al. Quality of life in adult survivors of critical illness: a systematic review of the literature. Intens Care Med 2005;31:611—20. 10. Findler M, et al. The reliability and validity of the SF-36 health survey questionnaire for use with individuals with traumatic brain injury. Brain Injury 2001;15(8): 715—23. 11. Gabbe BJ, et al. Choosing outcome assessment instruments for trauma registries. Acad Emerg Med 2005;12(8):751—8. 12. Girotto JA, et al. Long-term physical impairment and functional outcomes after complex facial fractures. Plast Reconstr Surg 2001;108(2):312—27. 13. Hall SE, et al. Hip fracture outcomes: quality of life and functional status in older adults living in the community. Aust NZ J Med 2000;30(3):327—32. 14. Helps, Y, Cripps R, Harrison J. Hospital separations due to injury and poisoning, Australia 1999—2000. Injury Research and Statistics Series Number 15. AIHW Cat. No. INJCAT 48. Adelaide: Australian Institute of Health and Welfare; 2002. p. 40. 15. Holbrook TL, et al. Outcome after major trauma: discharge and 6-month follow-up results from the Trauma Recovery Project. J Trauma 1998;45(2):315—23 [discussion 323—4]. 16. Holbrook TL, et al. Outcome after major trauma: 12-month and 18-month follow-up results from the Trauma Recovery Project. J Trauma 1999;46(5):765—71 [discussion 771—3]. 17. Holbrook TL, Hoyt DB, Anderson JP. The importance of gender on outcome after major trauma: functional and psychologic outcomes in women versus men. J Trauma 2001;50(2):270—3. 18. Holbrook TL, Hoyt DB, Anderson JP. The impact of major inhospital complications on functional outcome and quality of life after trauma. J Trauma 2001;50(1):91—5.
L.M. Aitken et al. 19. Hoogendoorn JM, van der Werken C. Grade III open tibial fractures: functional outcome and quality of life in amputees versus patients with successful reconstruction. Injury 2001;32(4):329—34. 20. Inaba K, et al. Long-term outcomes after injury in the elderly. J Trauma 2003;54(3):486—91. 21. Kyes KB, Franklin G, Weaver MR. Reliability and validity of medical outcome and patient satisfaction measures among injured workers in Washington state: a pretest. Am J Ind Med 1997;31(4):427—34. 22. MacKenzie EJ, et al. Using the SF-36 for characterizing outcome after multiple trauma involving head injury. J Trauma 2002;52(3):527—34. 23. MacKenzie EJ, et al. Functional outcomes following traumarelated lower-extremity amputation. J Bone Joint Surg Am A 2004;86(8):1636—45. 24. MacKenzie EJ, et al. Long-term persistence of disability following severe lower-limb trauma. Results of a seven-year follow-up. J Bone Joint Surg Am 2005;87(8):1801—9. 25. Mathers, C, Vos, T, Stevenson, C. The burden of disease and injury in Australia. AIHW Cat. No. PHE 17. Canberra: Australian Institute of Health and Welfare; 1999. 26. McCallum J. The SF-36 in an Australian sample: validating a new, generic health status measure. Aust J Public Health 1995;19(2):160—6. 27. McCarthy ML, et al. Functional status following orthopedic trauma in young women. J Trauma 1995;39(5):828—36 [discussion 836—7]. 28. Obremskey WT, et al. Change over time of SF-36 functional outcomes for operatively treated unstable ankle fractures. J Orthop Trauma 2002;16(1):30—3. 29. Oliver CW, et al. Outcome after pelvic ring fractures: evaluation using the medical outcomes short form SF-36. Injury 1996;27(9):635—41. 30. Paniak C, et al. Sensitivity of three recent questionnaires to mild traumatic brain injury-related effects. J Head Trauma Rehabil 1999;14(3):211—9. 31. Peden M, McGee K, Krug E, editors. Injury: a leading cause of the global burden of disease, 2000. Geneva: World Health Organisation; 2002. 32. Pezzin LE, Dillingham TR, MacKenzie EJ. Rehabilitation and the long-term outcomes of persons with trauma-related amputations. Arch Phys Med Rehabil 2000;81(3):292—300. 33. Randell AG, et al. Deterioration in quality of life following hip fracture: a prospective study. Osteoporos Int 2000;11(5): 460—6. 34. Ristner G, et al. Sense of coherence and lack of control in relation to outcome after orthopaedic injuries. Injury 2000;31(10):751—6. 35. Shadbolt B, McCallum J, Singh M. Health outcomes by selfreport: validity of the SF-36 among Australian hospital patients. Qual Life Res 1997;6(4):343—52. 36. Shapiro ET, et al. The use of a generic, patient-based health assessment (SF-36) for evaluation of patients with anterior cruciate ligament injuries. Am J Sports Med 1996;24(2):196— 200. 37. Ware, JE, Snow KK, Kosinski M. SF-36 Health Survey: Manual and Interpretation Guide. Lincoln: Quality Metric Incorporated; 2000. 38. Ware Jr JE, Sherbourne CD. The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection. Med Care 1992;30(6):473—83. 39. Ware Jr JE. SF-36 health survey update. Spine 2000;25(24): 3130—9. 40. Wilson IB, Cleary PD. Linking clinical variables with healthrelated quality of life. A conceptual model of patient outcomes. JAMA 1995;273(1):59—65.