ADVERTISEMENT
Assessing Quality of Life in Patients with Chronic Leg Ulceration using the Medical Outcomes Short Form-36 Questionnaire
Abstract
Clinician awareness of the importance of recognizing, assessing, and ultimately addressing the negative impact of chronic wounds on patient quality of life is increasing. One hundred, eighteen (118) patients (average age 78 years) participated in a study to evaluate the use of the Medical Outcomes Short Form-36 for assessing the health-related quality of life of patients with chronic leg ulceration.
Most patients (104; 88%) were treated at home by community nurses. A medical history was obtained and patients completed the Short Form-36 questionnaire at baseline and after 12 weeks of receiving standard ulcer care. Published normative data were used to ascertain the effect of leg ulcers on health-related quality of life. Short Form-36 responsiveness was determined by comparing baseline and 12-week scores. Results suggest that the questionnaire is reliable for five of eight Short Form-36 domains (α >0.8), with the remainder α >0.7. Compared to age-sex adjusted published normative scores, patients with leg ulcers had significantly lower mean scores in the following domains: role-emotional (d = 28.6, P <0.001), social functioning (d = 22.8, P <0.001), role-functioning (d = 20.8, P <0.001), role-physical (d = 20.7, P <0.001), and bodily pain (d = 12.3, P <0.001). Short Form-36 scores barely changed between baseline and the 12-week assessment, but bodily pain improved in the 31 patients whose ulcers healed during that time (d = 14.6, P = 0.006; SRM = 0.60). Pain did not improve in patients whose ulcers remained open (d = -2.1, P = 0.45). Compared to patients whose ulcers did not heal, patients with healed ulcers experienced greater improvements in the following domains: body pain (d = 16.8, P = 0.003), mental health (d = 9.4, P = 0.013), role-physical (d = 19.7, P = 0.06), role-emotional (d = 17.2, P = 0.12), and vitality (d = 9.0, P = 0.052). The results of this study suggest that leg ulcers reduce patient quality of life and that the Short Form-36 can be used to ascertain their impact.
Chronic leg ulceration is a problem that is largely, although not exclusively, associated with advanced age. Although caused by a number of conditions, in the UK and US, leg ulceration is largely due to venous and arterial disease and complications of diabetes and rheumatoid arthritis.1,2 In the UK, patients with leg ulcers are most commonly treated by community services that provide high compression bandaging where deemed appropriate or referred for more complex etiologies.3 Community nursing is provided by one agency within a geographical area. More than 80% of patients are managed in their homes or in general practice clinics by community nurses.4 This makes identification of patients a relatively simple exercise in the UK.
Previous research has examined the role of leg ulceration in patients' health-related quality of life (HRQoL). Qualitative studies explored the experience of living with a venous ulcer and brought attention to the problem of living with pain, restrictions caused by the ulcer, and patients' ability to cope with the ulcer by adjusting health expectations.5,6 Clinicians interested in quality-of-life assessment in patients with leg ulceration have generally preferred to use the Nottingham Health Profile (NHP) instead of the Medical Outcomes Short Form-36 (SF-36) questionnaire. The NHP has been used in cross-sectional studies7-9 and as an outcome of treatment in clinical trials of therapy.10-11 It suggests "to be sensitive to the differences between patients with ulcerations and the general population."7-9 
Evidence from a small study conducted by Price and Harding12 suggests that patients with leg ulceration have a deficit in HRQoL as assessed using the SF-36. A study involving a larger sample (n = 233) set within a clinical trial indicated that some of the characteristics of the SF-36 were less than optimal in this patient group and failed to find health gains in any of the domains of the SF-36 after successful treatment.13 The purpose of this study was to evaluate the use of the SF-36 in a group of patients with chronic leg ulceration and assess its value as a health indicator following a 12-week period of treatment.
Methods
Patient population. Patients in this study were recruited in a case identification exercise within the geographical area that encompassed community services (ie, general practice surgeries and community nurses) and hospital services (outpatient and inpatient) within the designated area. A questionnaire was sent to all community staff and hospital wards asking them to provide details of current patients with leg ulcers. Responses were collated and duplicates were accounted for by reference to patients' initials, date of birth, and gender. Patients were identified within the north and south sectors of Redbridge Community NHS Trust, London, UK where they were receiving nursing care for their ulcerations.
During the study, nurses continued to treat patients according to their clinical preferences (what they felt was appropriate) and availability of wound care products. The questionnaire was administered to all patients who agreed to take part in the study. Each patient was interviewed and asked to complete the SF-36 questionnaire at the baseline audit. Twelve weeks after the first questionnaire, patients were re-interviewed to determine the clinical outcome of their care and to repeat the SF-36. Standard questionnaires were used to describe patients and evaluate clinical and HRQoL outcomes of care. This questionnaire included standard demographic information, general medical history, ulcer details, and the SF-36 questionnaire to evaluate HRQoL.
The SF-36 questionnaire. Patients were assessed for HRQoL using the UK version of the SF-36 questionnaire.14 This is a generic tool containing 36 questions that are combined to produce eight scores ranging from zero (worst possible) to 100 (best possible) HRQoL. SF-36 scores relate to physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health. The SF-36 was chosen based on its successful use in population studies15,16 and its extensive use with the elderly, particularly within an interview setting.16,17
Statistical methods. Initial investigation of the use of the SF-36 involved an assessment of the floor and ceiling effects within each derived domain and an estimation of internal reliability described by the alpha (a) coefficient determined from the individual questions that make up each domain. This methodology has been used elsewhere to describe the features of the SF-36 in the elderly.17 The ceiling effect describes the proportion of a sample who record the best score possible (100). A high ceiling effect limits the usefulness of a tool because patients can show no improvement in their health state despite best possible clinical outcomes of care. The floor effect determines the proportion of patients who have the worst possible health score. This also limits the value of a tool since patients cannot get worse than they are presently. The alpha (a) coefficient provides an indication of how well the tool performs within the specific patient group. A high a coefficient indicates that the questions that comprise the scales are highly related, a necessary requirement for use of a tool within a particular patient group.
Because no standard "normal" population scores exist that encompass all age groups in the UK, two sources were utilized; one used the SF-36 in 9,332 people, aged 18 to 64 years15; and one examined 1,608 people over the age of 70 years.16 The normative data for patients ages 65 to 70 were estimated as the mean for patients age 60 to 65 years in the first study and as the mean for patients age 70 to 75 years in the second. For each patient, a matched age-gender score was determined from these normative data and compared with the patient's own scores for each domain. The mean matched pairs differences between the normative and patients' scores were calculated (given as "d") and presented along with 95% confidence intervals determined from the standard errors of these mean differences. Inferential testing was performed using the paired t -test. A similar strategy was adopted to determine the changes in scores over the treatment period. The sensitivity to change was examined by computing the standardized response mean (SRM).18 The SRM is calculated by dividing the mean score change by the standard deviation of the score change. An SRM of 0.2 is considered to be small, 0.5 is moderate, and 0.8 is large. Responsiveness also was determined by comparing the mean improvement in scores between patients whose ulcers closed over the 12-week period and patients whose ulcers failed to close.
Results
Baseline data. Participants were elderly and included many more women than men (see Table 1). More than 10% of all patients had diabetes, 20% had hypertension, and 14% had a history of deep vein thrombosis, an important cause of venous ulceration. Although most (70%) ulcers were small (<10 cm2), the duration of ulceration was often considerable. Of all the patients, 50% had an ulcer present for longer than 1 year and 21% had their current ulcer for longer than 5 years. Mobility was a problem in many patients. Although only 3% were bed- or chair-bound, 16% were only able to walk about indoors. To compound the problem of the leg ulcer, 11% of patients had a fixed ankle, a recognized independent risk factor for poor healing in patients with venous ulceration.19
Use of the SF-36 in patients with leg ulceration. The highest number of uncompleted questions was observed in the physical function domain, with 96 of 118 (81%) questions completed (see Table 2). Internal consistency was good for five of eight domains (a >0.8), the remainder being greater than 0.7. The range of ceiling effects (an SF-36 score of 100 indicating best possible health) varied from 2% in physical functioning and vitality up to 51% in role-emotional. Conversely, the floor effects (health cannot become worse than it is) ranged from zero for mental health to 50% in the role-physical domain. 
Comparison of patient and population normal scores. Considerable differences in scores between patients with leg ulceration and age-gender matched population means were observed (see Table 3). The greatest mean differences (d) were seen in the role-emotional (d = 27.9, P <0.001), social functioning (d = 22.0, P <0.001), role-physical (d = 21.5, P <0.001) and physical functioning domains (d = 21.0, P <0.001). In addition, both bodily pain (d = 12.3, P <0.001) and mental health (d = 0.42, P =0.040) achieved a standard level of statistical significance. Scant differences in general health and vitality were noted between the patients with leg ulceration and the general population (d = 3.3 and 2.4, respectively). 
Treatment outcomes. The 118 patients involved in this study had 138 ulcerated limbs. After 12 weeks of treatment, 31 of the remaining 111 patients (28%) had no areas of ulceration on either limb (ulcer closure), with 47 out of 138 (34%) limbs healed. Three limbs developed new ulcers over the study period. Changes in ulcer size over the 12 weeks, as determined by the patient, indicated that 37% had become smaller and 8% had increased in size.
Changes in health-related quality of life. Only a small difference was observed between first and 12-week visit scores (see Table 4). The greatest improvement was in bodily pain (d = 2.1,) but the difference was not statistically significant (P = 0.41). 
In patients who experienced complete ulcer closure, improvements in bodily pain were statistically significant (d = 14.6, P = 0.006). In this group, substantial improvements also were observed in role-emotional (d = 14.5), role-physical (d = 13.5), and vitality (d = 6.8), although none of these achieved statistical significance due to the small sample size (see Table 5). For patients with unhealed ulceration, a significant reduction in mental health (d = -4.1, P = 0.027) and a substantial though nonsignificant reduction in the role-physical score (d = -6.4) were noted, indicating generally poorer HRQoL after the 12 weeks of treatment. The Standardized Response Mean (SRM) results (see Table 6) indicate that the only scale achieving an acceptable responsiveness to change was for bodily pain in patients who achieved complete ulcer closure. The SRM of all other scores within the SF-36 were small and a number were negative, indicating a deterioration in HRQoL.
The impact of ulcer closure was further determined by examining the change in scores after 12 weeks of treatment between patients whose ulcers closed and whose ulcers remained open (see Table 7). Both bodily pain (d = 16.8, P = 0.003) and mental health (d = 9.4, P = 0.013) showed significantly greater improvements in the patients whose ulcers had closed, with role-physical (d = 19.7, P = 0.06), role-emotional (d = 17.2, P = 0.12), and vitality (d = 9.0, P = 0.052) showing large, though nonsignificant, differences between groups. 
Discussion
This study examined the health-related quality of life of patients with leg ulceration, both in terms of their "expected" status, drawn from population normative data, and as an outcome of treatment within a community nursing service.
Walters et al13 used the SF-36 in a clinical trial comparing four-layer compression in a community clinic setting and home-based care provided by community nurses. Compared to this study, mean scores were lower for all domains of the SF-36 , with the largest difference observed in physical functioning (29.1 versus 43.4). While Walters et al13 did not observe a difference between closed and unhealed ulcerations (largest difference in physical functioning score = 3.7, P = 0.39), the present study documented substantial differences between these patient groups. Large improvements in SF-36 scores occurred in patients whose ulcers closed compared with those that remained open. In Walters' study,13 the SRMs were negative for most scores (both closed and unhealed); whereas, the SRMs in the current study were small but generally positive for patients whose ulcers healed, indicating a health gain.
Although the NHP has been considered as an alternative to the SF-36 in patients with chronic leg ulceration, its scoring method and large floor effects have been criticized.20 In the NHP, the floor effect (a score of zero) indicates best possible health. In a study of 758 patients with leg ulceration, floor effects varied between 18% for physical mobility and 67.5% for social isolation, with a median floor effect of 41% for the six domains that make up the NHP.21 By contrast, results of this study show a median ceiling effect of the eight domains of just 12%. However, the NHP is sensitive to change with effective treatment; NHP scores change substantially during effective ulcer treatment over follow-up periods of less than 6 months, with greater benefits perceived by patients in whom complete closure is achieved.10,11 More recently, research has indicated that these initial changes may not be sustained over time, probably due to the generalized deterioration of elderly patients or possibly to a regression in perceived health following the initial enthusiasm after healing the ulcer.22 One surprising result of the present study was the lack of change noted in patients following treatment, with only small score changes observed over the 12 week study period. In patients whose ulcers closed, three of the domains showed substantial changes (>10), of which only bodily pain achieved a standard level of significance. In a clinical trial of effective treatment, significant improvements have been demonstrated for most domains of the NHP with improvements >10 units in bodily pain and sleep.10 In a second trial, improvements of >10 were found for the same domains for healed ulcers together with energy levels and improvement in bodily pain in patients whose ulcers failed to heal.11 Clearly, changes need to be observed and documented in the SF-36 in patients during periods of effective leg ulcer treatments.
Conclusion
This study has demonstrated that the SF-36 can be used to determine the outcome of treatment in patients with chronic leg ulceration. The responsiveness of the SF-36 to changes in ulcer status remains an area of concern, although it has been shown that the SF-36 can detect differences between patients whose ulcers did and patients whose ulcers did not heal.
The SF-36 and NHP questionnaires are still largely considered to be research tools. However, the results of this study have confirmed that overall bodily pain experienced by patients with leg ulceration improves following closure. The benefits of ulcer closure also are likely to be reflected in improvements in the performance of daily activities (role-physical), energy levels (vitality), and psychological well being (mental health and role-emotional).
Prof. Franks, Professor of Health Science, and Prof. Moffatt, Professor of Nursing, are Co-directors of the Centre for Research and Implementation of Clinical Practice Faculty of Health and Human Sciences, Thames Valley University, London, UK. Ms. McCullagh is a Clinical Nurse Specialist at Redbridge Health Care NHS Trust, Chadwell Heath Hospital, Essex, UK. Please address correspondence to: Peter J. Franks, Centre for Research and Implementation of Clinical Practice, Faculty of Health and Human Sciences, Thames Valley University, 32-38 Uxbridge Road, London W5 2BS, UK; email: peter.franks@tvu.ac.uk.
1. Ruckley CV, Dale JJ, Callam MJ, Harper DR. Causes of chronic leg ulcer. Lancet. 1982;2:615.
2. Nelzen O, Berqvist D, Lindhagen A. Leg ulcer etiology - a cross sectional population study. J Vasc Surg. 1991;14:557.
3. Moffatt CJ, Franks PJ, Oldroyd M, et al. Community clinics for leg ulcers and impact on healing. British Medical Journal. 1992;305:1389-1392.
4. Callam MJ, Ruckley CV, Harper DR, Dale JJ. Chronic ulceration of the leg: extent of the problem and provision of care. British Medical Journal. 19"85;290:1855-1856.
5. Krasner D. Painful venous ulcers: themes and stories about their impact on quality of life. Ostomy/Wound Management. 1998;44:38-49.
6. Walshe C. Living with a venous ulcer: a descriptive study of patients' experiences. J Adv Nurs. 1995;22:1092-1100.
7. Lindholm C, Bjellerup M, Christensen OB, Zederfeld B. Quality of life in chronic leg ulcers. Acta Derm Venereol. (Stockholm) 1993;73:440-443.
8. Franks PJ, Moffatt CJ. Who suffers most from leg ulceration? J Wound Care. 1998;7:383-385 .
9. Hamer CC, Cullum NA, Roe BH. Patients' perceptions of chronic leg ulceration. Journal of Wound Care. 1994;3:99-101.
10. Franks PJ, Bosanquet N, Brown D, Straub J, Harper DR, Ruckley CV. Perceived health in a randomized trial of treatment for chronic venous ulceration. Eur J Vasc Endovasc Surg. 1999;13:3-17.
11. Franks PJ, Moffatt CJ, Connolly M, et al. Quality of life in a randomised trial in venous leg ulceration. Phlebology. 1999;14:95-99.
12. Price P, Harding K. Measuring health-related quality of life in patients with chronic ulcers. Wounds. 1996;8:91-94.
13. Walters SJ, Morrell CJ, Dixon S. Measuring health-related quality of life in patients with venous ulcers. Qual Life Res. 1999;8:327-336.
14. Ware JE, Snow KK, Kosinski M, Gandek B. SF-36 Health Survey: Manual and Interpretation Guide. Boston, Mass. The Health Institute, New England Medical Center; 1993.
15. Jenkinson C, Coulter A, Wright L. Short form 36 (SF-36) health survey questionnaire: normative data for adults of working age. British Medical Journal. 1993;306:1437-1444.
16. Lyons RA, Crome P, Monaghan S, Killalea D, Daley JA. Health status and disability among elderly people in three UK districts. Age Ageing. 1997;26:203-209.
17. Lyons RA, Perry HM, Littlepage BNC. Evidence of the validity of the short form 36 questionnaire (SF-36) in an elderly population. Age Ageing. 1994;23:182-184.
18. Liang MH, Fossel AH, Larson MG. Comparisons of five health status instruments for orthopaedic evaluation. Medical Care. 1990;28:632-642.
19. Franks PJ, Moffatt CJ, Oldroyd M, et al. Factors associated with healing leg ulceration using high compression. Age Ageing. 1995;24:407-410.
20. Kind P, Carr-Hill R. The Nottingham health profile: a useful tool for epidemiologists? Soc Sci Med. 1987;25:905-910.
21. Franks PJ, Moffatt CJ. Health related quality of life in patients with venous ulceration: use of the Nottingham health profile. Qual Life Res. 2001;10:693-700.
22. Moffatt CJ, Doherty D, Franks PJ. The long term effects of treatment on quality of life in chronic leg ulceration. Presented to the First World Wound Healing Congress, Melbourne, Australia. September 10-13, 2000.
