Diabetic foot ulcers - predictors of healing time and aspects of telemedicine

Abstract

Background: A diabetic foot ulcer (DFU) is a feared complication of diabetes. Both duration and severity of ulcer before start of treatment in specialist health care are factors that can effect healing time for patient with DFUs. More research about duration and severity of DFUs before seeking care as predictors of healing time might contribute to knowledge of importance for clinical interventions. Treatment of DFUs puts pressure on the health care system in terms of utilization of available resources. Moreover, the prevalence of diabetes is increasing dramatically and, as a result, longterm diabetes-related complications are also likely to increase. Telemedicine can be one way to address these issues, because telemedicine follow up may enable more integrated care pathways across health care levels. Telemedicine has been used in different settings, but knowledge of telemedicine’s effect on clinical outcomes and patients’ experiences among patients with DFUs is limited. Aims: The overall aim of this study was to provide new knowledge about predictors of healing time in patients with a DFU and to assess the effect of and experience with a telemedicine intervention for patients with a DFU. To achieve the overall aim, three specific aims were established: 1) to investigate whether A) duration of ulcer before start of treatment in specialist health care, and B) severity of ulcer according to the University of Texas (UT) classification system at the start of treatment (baseline), are independent predictors of healing time; 2) to evaluate whether telemedicine follow up of patients with DFUs treated in primary health care, in collaboration with hospital outpatient specialist care, is noninferior to standard outpatient care in terms of ulcer healing time. Further, to assess for superior whether amputations, death, consultations and patient satisfaction are different from telemedicine follow up compared to standard outpatient care; and, 3) to explore the experiences of patients with DFUs receiving telemedicine compared to patients receiving standard outpatient care health care delivered in the context of a cluster randomised controlled trial. Methods: Three different study designs were used. Study I: A retrospective cohort study included data from electronic medical records system of 105 patients with new DFUs from two outpatient clinics in Western Norway during 2009-2011. Competing risk regression with adjustment for potential confounders was used to evaluate the associations of duration and severity of the ulcer with healing time. Study II: In this pragmatic cluster randomised controlled non-inferiority trial, 182 patients (94/88 in telemedicine/standard outpatient care; 42 clusters) with a new DFU were recruited from three hospital outpatient clinics in Western Norway (from September 2012 to June 2016). The primary endpoint was healing time and secondary endpoints included amputation, death, number of consultations per month, and patient satisfaction. Study III: In the qualitative study individual interviews were conducted with 24 adults recruited from the cluster randomised controlled non-inferiority trial (n=13/ n=11 from the telemedicine /standard outpatient care group) in the period March 2014-May 2015. Results: Study 1: Of the 105 adults, 48 (45.7%) achieved ulcer healing, 38 (36.2%) underwent amputations, 10 (9.5%) died before ulcer healing and 9 (8.5%) were lost to follow up. For those who healed, mean healing time was 3.8 months (113 days), measured from start of treatment in the specialist health care to end of follow up. Time from patient-reported ulcer onset to referral by general practitioner (GP) to specialist health care was found to be a strong predictor of healing time. Patients who were referred to specialist health care by a GP ≥ 52 days after ulcer onset had a 58% (Sub hazard ratio (SHR) 0.42, CI 0.18, 0.98) decreased healing rate compared with patients who were referred earlier. Ulcers with the highest severity i.e. ulcer penetrating to tendon or bone (grade 2/3) and peripheral arterial disease with and without infection (stage C/D) according to the UT classification system had an 86% (SHR 0.14, CI 0.05, 0.43) decreased healing rate compared with low severity i.e. superficial ulcer (grade 1) with infection (stage A/B) or ulcer penetration to tendon/capsula (grad 2) and clean ulcer (stage A). Study II: Of 182 patients, 142 (78.9%) achieved complete ulcer healing, and 75 (79.8%) healed in the telemedicine group and 67 (76.1%) in the standards outpatient care group. Mean healing including only those who healed was 3.4 months and 3.8 months in the telemedicine group and standard outpatient group, respectively. Telemedicine was non-inferior to standard outpatient care regarding healing time (mixed-effects regression analysis: (mean difference –0.43 months, 95% CI –1.50, 0.65). This finding persisted also after taking into account competing risk from death and amputation (SHR 1.16, 95% CI 0.85, 1.59). There were no significant differences between the telemedicine follow up and standard outpatient care related to the effect estimate of the secondary outcomes, except for significantly fewer amputations in the telemedicine group. Study III: Three themes emerged from the analysis: 1) competence of health care professionals, 2) continuity of care, and 3) easy access, i.e. to receive treatment and follow up near home or at their home. Group allocation seemed to have limited impact on the patients’ follow-up experiences. Competence of health care professionals and continuity of care were important, because they could either enhance or impair wound care. When telemedicine functioned as intended, it was an advantage in the treatment. Easy access was important for the participants, but the importance of accessibility appeared only when competence among health care professionals and continuity of care were present. Conclusions: Early referral to specialist health care if an ulcer occurs is crucial for optimal ulcer healing and has a clear implication for routine care. Grade and stage severity are also important predictors for healing time, and early screening to assess the severity and initiation of prompt treatment is important. Telemedicine can be an alternative but also a supplement to usual care for patients with DFUs, at least for patients with more superficial ulcers. As the number of outpatient clinic consultations in the telemedicine group did not differ from the standard care group, there is need to focus on organisational aspects to facilitate the use of telemedicine. Health care professionals’ competence, continuity of care and easy access to health care services were essential for patients with DFUs, and telemedicine may compensate for lack of these factors.