Cochrane

# Supplementary material 8 to:
Interventions for preventing falls in older people living in the community

Gillespie LD , Robertson MC , Gillespie WJ , Sherrington C , Gates S , Clemson L , Lamb SE
https://doi.org/10.1002/14651858.CD007146.pub3

Cochrane disclaims all liability and responsibility arising from any reliance placed on this supplementary material which has been supplied by the author(s). The above associated publication’s Author Licence will apply in respect of any supplemental materials published. How to cite the supplementary material is defined in the Cochrane policy.

# 'Risk of bias' assessment tool

Domain | Criteria for judging risk of bias
--- | ---
Random sequence generation Relating to selection bias (biased allocation to interventions) due to inadequate generation of a randomised sequence | Judgement of 'Low risk' if A random component in the sequence generation was described, e.g. referring to a random number table; using a computer random number generator; coin tossing; shuffling cards or envelopes; throwing dice; drawing of lots; minimisation. Judgement of 'High risk' if A systematic non-random method was used, e.g. date of admission; odd or even date of birth; case record number; clinician judgement; participant preference; patient risk factor score or test results; availability of intervention. Judgement of 'Unclear' if Insufficient information about the sequence generation process to permit judgement of 'Low risk' or 'High risk'.
Allocation concealment Relating to selection bias (biased allocation to interventions) due to inadequate concealment of allocations prior to assignment | Judgement of 'Low risk' in studies using individual randomisation if Allocation concealment was described as by central allocation (telephone, web-based, or pharmacy-controlled randomisation); sequentially-numbered identical drug containers; sequentially-numbered, opaque, sealed envelopes. in studies using cluster randomisation if Allocation of all cluster units performed at the start of the study AND Individual participant recruitment was completed prior to assignment of the cluster, and the same participants were followed up over time OR individual participants were recruited after cluster assignment, but recruitment carried out by a person unaware of group allocation and participant characteristics (e.g. fall history) OR individual participants in intervention and control arms were invited by mail questionnaire with identical information. Judgement of 'High risk' in studies using individual randomisation if Investigators enrolling participants could possibly foresee assignments and thus introduce selection bias, e.g. using an open random allocation schedule (e.g. a list of random numbers); assignment envelopes unsealed, non-opaque, or not sequentially numbered; alternation or rotation; date of birth; case record number; or any other explicitly unconcealed procedure. in studies using cluster-randomisation if Individual participant recruitment was undertaken after group allocation by a person who was unblinded and may have had knowledge of participant characteristics. Judgement of 'Unclear' if Insufficient information to permit judgement of 'Low risk' or 'High risk'. This is usually the case if the method of concealment is not described or not described in sufficient detail to allow a definite judgement, e.g. if the use of assignment envelopes is described, but it remains unclear whether envelopes were sequentially numbered, opaque and sealed.
Blinding of participants and personnel Relating to performance bias due to knowledge of the allocated interventions by participants and personnel carrying out the interventions | Judgement of 'Low risk' if Blinding of participants and personnel implementing the interventions ensured, and unlikely that the blinding could have been broken (e.g. control group received matching placebo medication prepared by a pharmacist) OR no blinding or incomplete blinding, but the review authors judge that the outcomes (falls and fractures) are not likely to be influenced by lack of blinding. Judgement of 'High risk' if Participants and/or intervention delivery personnel were not blind to group allocation (e.g. exercise intervention), and the outcomes (falls and fractures) are likely to be influenced by lack of blinding. Judgement of 'Unclear' if Insufficient information to make a judgement of 'Low risk' or 'High risk'.
Blinding of outcome assessment Relating to detection bias due to knowledge of the allocated interventions by outcome assessors | a. Falls and fallers: Judgement of 'Low risk' if Falls were recorded/confirmed in all allocated groups using the same method AND the personnel recording/confirming falls were blind to group allocation. Judgement of 'High risk' if Falls were NOT recorded/confirmed in all allocated groups using the same method OR the personnel recording/confirming falls were NOT blind to group allocation. Judgement of 'Unclear' if Insufficient information to make a judgement of 'Low risk' or 'High risk'. b. Fractures: Judgement of 'Low risk' if Fractures were recorded/confirmed in all allocated groups using the same method AND fractures were confirmed by the results of radiological examination or from primary care case records AND the personnel recording/confirming fractures were blind to group allocation. Judgement of 'High risk' if Fractures were NOT recorded/confirmed in all allocated groups using the same method OR the only evidence for fractures was from self reports from participants or carers. Judgement of 'Unclear' if Insufficient information to make a judgement of 'Low risk' or 'High risk'.
Incomplete outcome data Relating to attrition bias due to amount, nature or handling of incomplete outcome data | a. Falls See Supplementary material 9 for details. b. Fallers See Supplementary material 9 for details.
Method of ascertaining falls Relating to bias in the recall of falls due to unreliable methods of ascertainment | Judgement of 'Low risk' if The study used some form of concurrent collection of data about falling, e.g. participants given postcards to fill in daily and mail back monthly, calendar to mark etc, with monthly, or more frequent, follow-up by the researchers. Judgement of 'High risk' if Ascertainment relied on participant recall at longer intervals than one month during the study or at its conclusion. Judgement of 'Unclear' if there was retrospective recall over a short period only, or details of ascertainment were not described, i.e. insufficient information was provided to allow a judgement of 'Low risk' or 'High risk'.

Adapted from Table 8.5.a 'The Cochrane Collaboration's tool for assessing risk of bias' and Table 8.5.d 'Criteria for judging risk of bias in the 'Risk of bias' assessment tool' (1)

## References

1. Higgins JPT , Altman DG , Sterne JAC (editors) . Chapter 8: Assessing risk of bias in included studies. In: Higgins JPT, Green S (editors). Cochrane Handbook of Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from www.cochrane-handbook.org.