Quality of Life for Patients Diagnosed with Diabetic Foot

Abstract

I recently had an interesting conversation with a colleague regarding the use of the Patient-Reported Outcome Measure (PROM) for diabetic foot–related problems. Essentially, the discussion focused on whether a generic health-related quality of life (HRQOL) assessment tool such as the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36) is sufficient to fully capture the quality of life experienced by a patient with diabetic foot problems. He suggested the need to use an additional region-specific HRQOL assessment tool because the SF-36 is not specific enough to reflect the unique issues encountered in the diabetic foot and ankle. He recommended the Foot and Ankle Ability Measurement (FAAM), which is more specific to foot and ankle function (1Martin R.L. Irrgang J.J. Burdett R.G. Conti S.F. Van Swearingen J.M. Evidence of validity for the Foot and Ankle Ability Measure (FAAM).Foot Ankle Int. 2005; 26: 968-983PubMed Google Scholar). He argued that the combination of a generic and a region/disease specific PROM is needed to capture all of the dimensions of the diabetic foot and ankle patient. As I began to think more about this conversation, larger questions began to emerge regarding the use of PROMs. The PROM is essentially a subjective set of questions that the patient answers regarding how he or she perceives his or her own physical and mental well-being. The idea is to assess how the disease or disability affects the quality of the patient's life. A score is generated that then can be compared with past and future scores and compared among patients. In this way, the disease or disability can be tracked over time or comparative effectiveness analysis can be performed for different interventions. The more generic health-related quality of life (HRQOL) assessment tools can even be used to compare between diseases or disabilities. For example, the PROM scores from a sample patient population with a specific type of cancer can be compared with the PROM scores from a sample patient population with diabetic foot ulcers. Even though these conditions are different, their HRQOL can be directly compared. Thus, HRQOL not only is a powerful analysis tool but also can have significant ramifications as to health care resource allocation. Many HRQOL assessment tools are used in the peer-reviewed published literature. The most frequently cited PROM is the SF-36, which is separated into 2 broad categories with 36 total questions: a mental component and a physical component (2Ware Jr., J.E. Sherbourne C.D. The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection.Med Care. 1992; 30: 473-483Crossref PubMed Scopus (28193) Google Scholar, 3Hays R.D. Shapiro M.F. An overview of generic health-related quality of life measures for HIV research.Qual Life Res. 1992; 1: 91-97Crossref PubMed Scopus (129) Google Scholar). The SF-36 contains 8 domains: physical functioning, bodily pain, general health perception, vitality, social functioning, role limitations due to physical health, role limitations due to emotional problems, and mental health. Scores to each questions in each domain are added, and a total score can be calculated that ranges from 0 to 100 (100 = highest score). The SF-12 is a shortened version. It contains only 12 questions but the same 8 domains as the SF-36. The SF-36 evolved from the RAND 36-item form (RAND-36) and utilizes a different scoring algorithm (436-Item Short Form Survey from the RAND Medical Outcomes Study. Rand Health. Available at: http://www.rand.org/health/surveys_tools/mos/mos_core_36item.html. Accessed July 18, 2013.Google Scholar). Another common HRQOL assessment tool is the EuroQOL 5D Health Utility Index (EQ-5D) (5EQ-5D. EuroQol Group. Available at: http://www.euroqol.org.html. Accessed July 18, 2013.Google Scholar). The EQ-5D contains 5 questions that encompass the following areas: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each question is answered with a number: 1 = no problem, 2 = moderate problem, 3 = severe problem. The EQ-5D also uses a 20-cm visual analog scale (VAS) and a question that asks the patient to compare his or her current health state to 1 year ago. A single score is calculated, and each domain is weighted differently. The result is a score from −0.594 to 1 (1 = highest score; <0 = worse than death). The PROM that clinicians probably use most widely, which they may not be aware they are using, is the VAS. The typical VAS instrument is a 10-cm pain-specific scale scored from 0 to 100. Diabetic foot–specific PROMs also are cited in the literature. Two commonly cited HRQOL assessment tools for patients with foot ulcerations are the Neuropathy- and Foot Ulcer–Specific Quality of Life Instrument (NeuroQoL) and the Cardiff Wound Index Scale (CWIS). The NeuroQoL contains 28 questions that use a 5-point Likert scale (i.e., “strongly agree” to “strongly disagree”) to assess 2 domains: physical factors (painful symptoms, reduced feeling, diffuse sensorimotor symptoms) and psychological factors (disruption of daily activities and interpersonal-emotional burden) (6Vileikyte L. Peyrot M. Bundy C. Rubin R.R. Leventhal H. Mora P. Shaw J.E. Baker P. Boulton A.J. The development and validation of a neuropathy- and foot ulcer-specific quality of life instrument.Diabetes Care. 2003; 26: 2549-2555Crossref PubMed Scopus (201) Google Scholar). Further, NeuroQol asks about the patient's overall HRQOL. The CWIS encompasses 47 questions in 4 domains: well-being, physical symptoms and daily living, social life, and overall quality of life (7Price P. Harding K. Cardiff Wound Impact Schedule: the development of a condition-specific questionnaire to assess health-related quality of life in patients with chronic wounds of the lower limb.Int Wound J. 2004; 1: 10-17Crossref PubMed Scopus (163) Google Scholar). Scores are tabulated from 0 to 100 (100 = highest). There are several non-ulcer foot- and ankle-related HRQOL tools, but most are not diabetes specific. The FAAM is comprised of 2 components: 21 questions related to activities of daily living and 8 questions related sports activities. This PROM has been validated specifically for use in the diabetic population (8Kivlan B.R. Martin R.L. Wukich D.K. Responsiveness of the foot and ankle ability measure (FAAM) in individuals with diabetes.Foot (Edinb). 2011; 21: 84-87Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar, 9Martin R.L. Hutt D.M. Wukich D.K. Validity of the Foot and Ankle Ability Measure (FAAM) in diabetes mellitus.Foot Ankle Int. 2009; 30: 297-302Crossref PubMed Scopus (43) Google Scholar). There are many other validated general and specific PROMs. The decision to use one over another can be debated but is largely a matter of preference. Hogg et al performed an excellent systematic review of PROMs as related to the diabetic foot (10Hogg F.R. Peach G. Price P. Thompson M.M. Hinchliffe R.J. Measures of health-related quality of life in diabetes-related foot disease: a systematic review.Diabetologia. 2012; 55: 552-565Crossref PubMed Scopus (93) Google Scholar). They reviewed both general and disease/region-specific HRQOL PROMs for published research conducted for diabetic foot related conditions. Of the studies they found, 53 of 203 studies met their eligibility criteria. They reported: “Of the generic tools, the SF-36 show sensitivity to foot disease and has been used most frequently…” They continued, “The CWIS shows promise in assessing HRQOL in active ulceration, but is non-specific for DFUs and may fail to capture aspects of this disease.” They concluded, “Using a combination of generic and disease-specific PROMS should produce the most meaningful outcomes, but as indicated by the poor response rate in one randomised trial, the use of two instruments (e.g. CWIS and SF-36) may be cumbersome and unfeasible in clinical practice.” There are several reasons why HRQOL assessment tools are important. One could argue that subjective PROMs are more important than objective, clinician-driven assessment instruments. One could argue that the only important thing is how the patient perceives his or her health state and response to treatment rather than how the clinician perceives it. For example, a 15% reduction in wound size dimensions is not as important to the patient as the drainage from their wounds causing them to avoid social interactions. Objective, clinician-driven assessment tools are important to gauge treatment progress and compare the effectiveness of treatment options. Further, the validated, objective assessment tools enable statistical comparisons for academic purposes. PROMs can also track patient progress and comparative effectiveness in perhaps a more meaningful way. A medical problem only becomes a “problem” if it keeps a person from doing what he or she wants to do. In other words, it is a problem if it affects quality of life. What better tool to asses this than a PROM? The discussion I had with a colleague came at an opportune moment because our division began using the SF-36 for all new patients presenting to our clinic beginning January 1, 2013. Patients are asked to fill out this form when they are scheduled for surgery and when they are admitted to the hospital; they are also asked to complete the form at 3-month intervals after surgery. We were the first division in the hospital to fully integrate this HRQOL assessment to our patient visits. Our initial expectation was that this tool would provide us with valuable data to integrate into our research effort, but soon we found this to be a useful tool to better understand the patient's perspective of their health state. Currently, patients fill this form out on paper, but soon our electronic medical records system will allow patients to directly input their responses digitally on a portable device while in our waiting room. As I reflect on the discussion, it becomes clear to me that it doesn't really matter which PROM is used as long as the tool has been validated (reliable, accurate, and reproducible). In my opinion, a more generic PROM is sufficient and does not require an additional region/disease-specific PROM. A general HRQOL assessment tool gets to the heart of why a PROM is being used in the first place, which is to assess how a patient's overall quality of life has been affected. HRQOL assessments are becoming important markers to track diseases and to compare treatment outcomes. This is true for clinicians in practice as well as for clinical research trials. Thanks to Dane K. Wukich, MD, for a thoughtful discussion that prompted me to write this article.