Peripheral artery disease (PAD) affected approximately 800 000 Canadians aged 25 years or older in 2015 and it poses a substantial risk of lower extremity amputation (LEA). While clinical risk factors for amputation are well-established, the impact of social determinants of health (SDoH) on amputation risk remains unclear, particularly in a Canadian context.

This systematic review aims to: (1) synthesise evidence on the associations between multilevel SDoH domains and LEA (both major and/or minor) risk in Canadian PAD patients including intersectional effects of race and ethnicity with another SDoH domain, and (2) evaluate the statistical methodologies used in the researched literature to inform future study design and analysis approaches.

We will systematically search MEDLINE, Embase, EmCare, Global Health, Cumulative Index to Nursing and Allied Health Literature and Web of Science for studies examining SDoH and LEA in Canadian patients with PAD (including chronic limb-threatening ischaemia which is a severe form of PAD). Date limits for each database will be from inception through December 2025. SDoH will be categorised using a modified Healthy People 2030 SDoH framework under six domains: economic stability, education, food, neighbourhood and physical environment, healthcare system and community and social context. Two reviewers will independently screen titles, abstracts and full texts, with discrepancies resolved by a third reviewer. Data will be extracted on study characteristics, SDoH measures, outcomes and statistical methods. Risk of bias will be assessed using RoB 2 for randomised trials, ROBINS-I for non-randomised studies of interventions and ROBINS-E for studies investigating exposures. A narrative synthesis, and where data permit, a Bayesian hierarchical meta-analysis using both effect size and contingency table approaches will be conducted. Statistical heterogeneity will be explored through subgroup analyses and meta-regression, examining study design, SDoH measurement approaches and population characteristics.

As a systematic review and meta-analysis, ethics approval is not required. For institutional oversight, we provide the contact of Dr Sonia Anand (Associate Vice-President, Global Health, McMaster University; anands@mcmaster.ca). Results will be reported following PRISMA guidelines and disseminated through a peer-reviewed publication.

CRD420251115759.

Photobiomodulation (PBM) has shown promising effects in managing postoperative pain following conventional periapical surgery, although current evidence remains limited. This study aims to assess the effect of PBM on postoperative pain 24 hours after periapical surgery.

A randomised, controlled, double-blind trial will include 34 patients undergoing periapical surgery in the maxillary region, randomly assigned to an experimental group (n=17) or control group (n=17). The experimental group will receive PBM (GaAlAs diode laser, 808 nm, 100 mW, 4 J/cm², applied at five vestibular points) and placebo ibuprofen immediately and 24 hours postoperatively. The control group will receive simulated PBM and active ibuprofen. The primary outcome is postoperative pain assessed by the visual analogue scale at 24 hours. Secondary outcomes include pain at the seventh day, paracetamol intake, oedema, ecchymosis, soft tissue status and temperature at 24 hours and 7 days. Radiographic evaluation of healing will be performed at 1 and 3 months. Statistical analysis will be conducted based on data distribution, using repeated measures ANOVA (Analysis of Variance) or non-parametric equivalents for longitudinal outcomes, and appropriate tests for categorical variables. Significance will be set at p

The study was approved by the Human Research Ethics Committee of Universidad Católica del Uruguay (process no. 220914). Results will be disseminated to participants, healthcare professionals, the public and scientific communities.

NCT05935306.