TY - JOUR
T1 - Multiple factors predict longer and shorter time-to-ulcer-free in people with diabetes-related foot ulcers
T2 - Survival analyses of a large prospective cohort followed-up for 24-months
AU - Zhang, Yuqi
AU - Cramb, Susanna
AU - McPhail, Steven M.
AU - Pacella, Rosana
AU - van Netten, Jaap J.
AU - Cheng, Qinglu
AU - Derhy, Patrick H.
AU - on behalf of the Diabetic Foot Working Group, Queensland Statewide Diabetes Clinical Network, Australia
AU - Kinnear, Ewan M.
AU - Lazzarini, Peter A.
N1 - Funding Information: This work was supported by the Chinese Scholarship Council and Australian National Health and Medical Research Council (Grant numbers 1143435 and 1161138). The funding sources had no role in study design, collection, analysis, interpretation, writing or decision to submit this manuscript for publication. Funding Information: The research on which this paper is based was conducted using the Queensland High Risk Foot Form Database resource. We are most grateful to the Diabetic Foot Working Group, Queensland Statewide Diabetes Clinical Network (Australia) and to the individual centers that provided the data. The authors acknowledge the participants of the Diabetic Foot Working Group: Kimberley Canning, Danielle Charles, Patrick Derhy, Pankaj Jha, Achamma Joseph, Ewan Kinnear (chair), Amy Langley, Shireen Lazaro, Peter Lazzarini, Rebecca Mann, Helen Martin, Sharon O'Rourke and Helen Sheahan. This work was supported by the Chinese Scholarship Council and Australian National Health and Medical Research Council (Grant numbers 1143435 and 1161138). The funding sources had no role in study design, collection, analysis, interpretation, writing or decision to submit this manuscript for publication. Declarations of interest. The authors declare that they have no relevant competing interests. YZ contributed to conception and design of the study, data acquisition, analysis and interpretation, drafted and critically reviewed the paper for intellectual content. SC contributed to conception and design of the study, data analysis and interpretation, drafted and critically reviewed the paper for intellectual content. SMM contributed to conception and design of the study, data interpretation and critically reviewed the paper for intellectual content. RP contributed to conception and design of the study, data acquisition, and critically reviewed the paper for intellectual content. JJvN and QC contributed to data analysis and interpretation and critically reviewed the paper for intellectual content. PHD and EMK contributed to conception and design of the study, data acquisition, and critically reviewed the paper for intellectual content. PAL contributed to conception and design of the study, data acquisition, analysis and interpretation, drafted and critically reviewed the paper for intellectual content. All authors reviewed and approved the final version of the article. The corresponding author had full access to all the data and final responsibility for publication submission. The data that support the findings of this study are available from the Queensland Statewide Diabetes Clinical Network and Queensland Health Statistics Branch, but restrictions apply to the availability of these data, which were used under approvals for the current study, and so are not publicly available. This data was made available to the authors following successful applications for Human Research Ethics Committee Approval and a Public Health Act waiver, a legal act of the Queensland Government. Thus, the data has been obtained from the data custodians, the Queensland Statewide Diabetes Clinical Network and Queensland Health Statistics Branch; only after an ethics application and Public Health Act waiver application were successfully approved. Data are however available to other researchers who follow this same process and contact the Queensland Health Statistics Branch at HSBresearch@health.qld.gov.au. Publisher Copyright: © 2022 Elsevier B.V.
PY - 2022/3/1
Y1 - 2022/3/1
N2 - Aims: To investigate factors independently associated with time-to-(being)-ulcer-free, time-varying effects and predict adjusted ulcer-free probabilities, in a large prospective cohort with diabetes-related foot ulcers (DFU) followed-up for 24 months. Methods: Patients presenting with DFU(s) to 65 Diabetic Foot Services across Queensland, Australia, between July-2011 and December-2017 were included. Demographic, comorbidity, limb, ulcer, and treatment factors were captured at presentation. Patients were followed-up until ulcer-free (all DFU(s) healed), amputation, death or two years. Factors associated with time-to-ulcer-free were investigated using both Cox proportional hazards and flexible parametric survival models to explore time-varying effects and plot predicted adjusted ulcer-free probability graphs. Results: Of 4,709 included patients (median age 63 years, 69.5% male), median time-to-ulcer-free was 112 days (IQR:40->730), with 68.4% ulcer-free within two years. Factors independently associated with longer time-to-ulcer-free were each year of age younger than 60 years, living in a regional or remote area, smoking, neuropathy, peripheral artery disease (PAD), ulcer size >1 cm2, deep ulcer and mild infection (all p < 0.05). Time-varying effects were found for PAD and ulcer size limiting their association to six months only. Shorter time-to-ulcer-free was associated with recent DFU treatment by a podiatrist and receiving knee-high offloading treatment (both p < 0.05). Predicted adjusted ulcer-free probability graphs reported largest differences in time-to-ulcer-free over 24-months for geographical remoteness and PAD factors. Conclusions: Multiple factors predicted longer and shorter time-to-ulcer-free in people presenting with DFUs. Considering these factors, their time-varying effects and adjusted ulcer-free probability graphs, should aid the prediction of the likely time-to-(being)-ulcer-free for DFU patients.
AB - Aims: To investigate factors independently associated with time-to-(being)-ulcer-free, time-varying effects and predict adjusted ulcer-free probabilities, in a large prospective cohort with diabetes-related foot ulcers (DFU) followed-up for 24 months. Methods: Patients presenting with DFU(s) to 65 Diabetic Foot Services across Queensland, Australia, between July-2011 and December-2017 were included. Demographic, comorbidity, limb, ulcer, and treatment factors were captured at presentation. Patients were followed-up until ulcer-free (all DFU(s) healed), amputation, death or two years. Factors associated with time-to-ulcer-free were investigated using both Cox proportional hazards and flexible parametric survival models to explore time-varying effects and plot predicted adjusted ulcer-free probability graphs. Results: Of 4,709 included patients (median age 63 years, 69.5% male), median time-to-ulcer-free was 112 days (IQR:40->730), with 68.4% ulcer-free within two years. Factors independently associated with longer time-to-ulcer-free were each year of age younger than 60 years, living in a regional or remote area, smoking, neuropathy, peripheral artery disease (PAD), ulcer size >1 cm2, deep ulcer and mild infection (all p < 0.05). Time-varying effects were found for PAD and ulcer size limiting their association to six months only. Shorter time-to-ulcer-free was associated with recent DFU treatment by a podiatrist and receiving knee-high offloading treatment (both p < 0.05). Predicted adjusted ulcer-free probability graphs reported largest differences in time-to-ulcer-free over 24-months for geographical remoteness and PAD factors. Conclusions: Multiple factors predicted longer and shorter time-to-ulcer-free in people presenting with DFUs. Considering these factors, their time-varying effects and adjusted ulcer-free probability graphs, should aid the prediction of the likely time-to-(being)-ulcer-free for DFU patients.
KW - Cohort study
KW - Cox proportional hazard model
KW - Diabetes-related foot ulcer
KW - Diabetic foot
KW - Flexible parametric survival model
KW - Ulcer-free
UR - http://www.scopus.com/inward/record.url?scp=85124473473&partnerID=8YFLogxK
U2 - https://doi.org/10.1016/j.diabres.2022.109239
DO - https://doi.org/10.1016/j.diabres.2022.109239
M3 - Article
C2 - 35131379
SN - 0168-8227
VL - 185
JO - Diabetes Research and Clinical Practice
JF - Diabetes Research and Clinical Practice
M1 - 109239
ER -