A systematic review and Meta-analysis on risk factors of delayed healing of venous leg ulcer

Objective To systematically review the risk factors of delayed healing of venous leg ulcer (VLU) so as to provide a guide for developing the personalized nursing strategies. Methods The Cochrane Library, PubMed, Web of Science, ScienceDirect, Clinicaltrials.gov, ProQuest and Open Grey was retrieved with the English keywords of "varicose ulcer/venous ulcer, non-healing/delayed healing/poor healing, factor/risk factor/influence factor"; the China Biological Medicine (CBM) , Chinese National Knowledge Infrastructure (CNKI) , WanFang Data and VIP was retrieved with the English keywords of "venous leg ulcer/venous ulcer, delayed healing/refractory, risk factors/influencing factors"; the retrieval time ranged from building database to 1st April 2019. Two researchers independently screened literatures, extracted data and assessed the quality of included literatures. The RevMan 5.3 was used to the meta-analysis. Results Finally, a total of 11 literatures were included and involved 3 894 subjects, 520 cases lost to follow up, 914 cases in case group and 2 460 in control group. Meta-analysis showed that there were 7 risk factors related to delayed healing of VLU including the ages [OR=1.02, 95%CI (1.01, 1.03) , P 50% wound covered with fibrin [OR=1.88, 95%CI (0.99, 3.57) , P=0.06], diabetes mellitus [OR=1.10, 95%CI (0.70, 1.75) , P=0.67], history of hip or knee replacement [OR=1.73, 95%CI (0.50, 6.00) , P=0.39]. Conclusions Evidence shows that the independent risk factors of delayed healing of VLU include the ages, range of motion of ankle, size of ulcer, duration of ulcer, history of DVT, ankle-brachial index<0.8 and rheumatoid arthritis. Those evidences can help to identify the clinical high-risk population of delayed healing of VLU and provide targeted nursing intervention to reduce the healing time of VLU and improve patients' quality of life. Key words: Meta-analysis; Varicose ulcer; Lower extremity veins; Delayed healing; Risk factors