Table 2 Inclusion criterion

General criteria

- Published before July 1, 2018.

- Related to the main topics: “the risk of falling in elderly people.” Articles not related to this topic will not be included based on the two-reviewer evaluation system.

Language criteria

- No language criteria are applied. However, for non-French, non-English, or non-Spanish articles, we will contact professional translators if no French, Spanish, or English version is found. Such translations will be indicated in the main article.

- All full papers will be retrieved (or translated) and used.

Type-of-study criteria

- Retrospective and prospective clinical trials, randomized, or not.

- Observational, time series, and cross-sectional studies.

Participants criteria

- Older patients (aged ≥ 60 years of age) considered to be otherwise healthy/without neurological disease as determined by a diagnostic assessment (or any specification from the authors) which could impact their posture including (but not limited to) Parkinson disease (PD), multiple sclerosis (MS), hemiplegia, paraplegic, stroke, or brain trauma. Orthopedic disorders affecting balance such as recent arthroplasty or amputation will also not be included in the review.

Intervention criteria

- Articles analyzing the balance through COP recordings during quiet standing with both feet on the ground and evaluating the risk of falling by the number of falls during a period of time (retrospectively or prospectively)

- Any article measuring the risk of falling without an estimation of the number of falls per participant (i.e., indirect assessment through fear of falling tests or epidemiologic data only) or not related to the risk of falling (comparing elderly vs. young for example) will be discarded.

- If training (e.g., exercise training or a physiotherapy program) is a part of the intervention, the article will be discarded unless a baseline of the quiet standing capacities is recorded. In this case, only the data from the baseline will be used.

Comparison criteria

- Fallers versus non-fallers (it can include “healthy elderly people” versus “fall prone elderly” or “low risk elderly” vs “high risk elderly” or “single fallers” versus “multiple fallers” or “infrequent fallers” versus “recurrent fallers”)

Outcomes criteria

- Primary outcomes will be the features in the COP analysis and their differences between the groups (odds ratio for dichotomous outcomes and mean differences for continuous outcomes).

- Secondary outcomes will be the precision of the prediction (or the model) of the risk of falling, such as sensibility, specificity, area under the curve (AUC) of receiver operating characteristic (ROC) curves, number of true(/false) positive(/negative), positive predictive value (PPV), and negative predictive value (NPV), odd-ratio or other evaluation of the system.