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Cited by 118Pediatric health and respiratory diseasesChild Nutrition and Water AccessPneumonia and Respiratory Infections

Effectiveness of handwashing with soap for preventing acute respiratory infections in low-income and middle-income countries: a systematic review and meta-analysis

Open access
Ross, Ian, Bick, Sarah, Ayieko, Philip, Dreibelbis, Robert, Wolf, Jennyfer, Freeman, Matthew C, Allen, Elizabeth, Brauer, Michael +1 more·2023·The Lancet
DOI 10.1016/s0140-6736(23)00021-1
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Abstract

Background Acute respiratory infection (ARI) is a leading cause of morbidity and mortality globally, with 83% of ARI mortality occurring in low-income and middle-income countries (LMICs) before the COVID-19 pandemic. We aimed to estimate the effect of interventions promoting handwashing with soap on ARI in LMICs. Methods In our systematic review and meta-analysis, we searched MEDLINE, Embase, Web of Science, Scopus, Cochrane Library, Global Health, and Global Index Medicus for studies of handwashing with soap interventions in LMICs from inception to May 25, 2021. We included randomised and non-randomised controlled studies of interventions conducted in domestic, school, or childcare settings. Interventions promoting hand hygiene methods other than handwashing with soap were excluded, as were interventions in health-care facilities or the workplace. The primary outcome was ARI morbidity arising from any pathogen for participants of any age. Secondary outcomes were lower respiratory infection, upper respiratory infection, influenza confirmed by diagnostic test, COVID-19 confirmed by diagnostic test, and all-cause mortality. We extracted relative risks (RRs), using random-effects meta-analysis to analyse study results, and metaregression to evaluate heterogeneity. We assessed risk of bias in individual studies using an adapted Newcastle-Ottawa scale, and assessed the overall body of evidence using a Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. The study is registered with PROSPERO, CRD42021231414. Findings 26 studies with 161 659 participants met inclusion criteria, providing 27 comparisons (21 randomised). Interventions promoting handwashing with soap reduced any ARI compared with no handwashing intervention (RR 0·83 [95% CI 0·76–0·90], I 2 88%; 27 comparisons). Interventions also reduced lower respiratory infections (0·78 [0·64–0·94], I 2 64%; 12 comparisons) and upper respiratory infections (0·74 [0·59–0·93], I 2 91%; seven comparisons), but not test-confirmed influenza (0·94 [0·42–2·11], I 2 90%; three comparisons), test-confirmed COVID-19 (no comparisons), or all-cause mortality (prevalence ratio 0·95 [95% CI 0·71–1·27]; one comparison). For ARI, no heterogeneity covariates were significant at p<0·1 and the GRADE rating was moderate certainty evidence. Interpretation Interventions promoting handwashing with soap can reduce ARI in LMICs, and could help to prevent the large burden of respiratory disease. Funding Bill & Melinda Gates Foundation, Reckitt Global Hygiene Institute, and UK FCDO.

AI snapshot

Written from the paper’s full text.

TL;DR

In LMICs, interventions promoting handwashing with soap reduced any acute respiratory infection by about 17% (RR 0.83, 95% CI 0.76–0.90) in a meta-analysis of 27 comparisons. Effects were also seen for lower and upper respiratory infections, but not for test-confirmed influenza, and no COVID-19 comparisons were identified.

Key findings

  • 26 studies with 161,659 participants provided 27 comparisons (21 randomised). Interventions promoting handwashing with soap reduced any ARI versus no handwashing intervention: RR 0.83 (95% CI 0.76–0.90), I² 88%; GRADE moderate certainty.
  • Lower respiratory infections were reduced: RR 0.78 (95% CI 0.64–0.94), I² 64%; upper respiratory infections were reduced: RR 0.74 (95% CI 0.59–0.93), I² 91%.
  • No significant effect was found for test-confirmed influenza: RR 0.94 (95% CI 0.42–2.11), I² 90%; there were no test-confirmed COVID-19 comparisons; all-cause mortality had one comparison: prevalence ratio 0.95 (95% CI 0.71–1.27).
  • Sensitivity analyses: randomised studies only RR 0.84 (0.76–0.93); domestic settings only RR 0.89 (0.81–0.97); majority handwashing messages RR 0.81 (0.73–0.90); studies adjusting for clustering RR 0.89 (0.82–0.96). No metaregression covariate was significant at p<0.10.

Methods

  • Systematic review and meta-analysis reported per PRISMA 2020 and registered with PROSPERO (CRD42021231414). Searched MEDLINE, Embase, Web of Science, Scopus, Cochrane Library, Global Health, and Global Index Medicus from inception to May 25, 2021, for English or French studies in LMICs; included randomised and non-randomised controlled studies in domestic, school, or childcare settings; excluded non-soap hand hygiene and health-care or workplace interventions.
  • Primary outcome was any ARI morbidity; secondary outcomes were lower respiratory infection, upper respiratory infection, test-confirmed influenza, test-confirmed COVID-19, and all-cause mortality. Used random-effects meta-analysis, metaregression, adapted Newcastle-Ottawa risk-of-bias assessment, and GRADE.
  • Included 26 studies, 161,659 participants, and 27 comparisons (21 randomised); 13 studies in Asia, nine in Africa, and three in Latin America; 18 interventions in domestic settings and nine in primary school or childcare settings; soap was provided in 16 interventions.

Limitations

  • Paper-stated: masking participants in handwashing interventions is impossible; primary outcome symptoms were typically caregiver- or self-reported; outcome measurement staff were not masked in almost all studies, so reporting bias could overstate effects, though exposure misclassification or low compliance might offset this.
  • Paper-stated: grey literature was not systematically searched; between-study heterogeneity was high and only partly explained by metaregression; non-randomised studies carry increased risk of bias; only two studies reported results by sex.
  • Evident from the text: some secondary outcomes rest on very few comparisons (test-confirmed influenza n=3; all-cause mortality n=1; no COVID-19 comparisons), and the primary analysis had substantial heterogeneity (I² 88%), limiting precision and certainty for those outcomes.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1016/s0140-6736(23)00021-1

Cites

54 of 54 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 35 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    For any ARI, no heterogeneity covariates were significant at p<0.1.

    “For ARI, no heterogeneity covariates were significant at p<0•1”
    Quote in the paperNot a substantial claim
  • Findingown data

    No comparisons of interventions promoting handwashing with soap on test-confirmed COVID-19 were available.

    “test-confirmed COVID-19 (no comparisons)”
    Quote in the paperNot a substantial claim
  • Findingown data

    Interventions promoting handwashing with soap reduced any ARI compared with no handwashing intervention (RR 0.83 [95% CI 0.76-0.90], I2 88%; 27 comparisons).

    “Interventions promoting handwashing with soap reduced any ARI compared with no handwashing intervention (RR 0•83 [95% CI 0•76-0•90], I² 88%; 27 comparisons).”
    • Also stated in: § Added value of this study · plain
      “In random effects meta-analysis of 27 comparisons, interventions promoting handwashing with soap reduced ARI by about 17% (relative risk 0•83 [95% CI 0•76-0•90], I 2 88%) compared with no handwashing intervention.”
    Quote in the paperSubstantial claim
  • Findingown data

    Interventions promoting handwashing with soap did not reduce all-cause mortality (prevalence ratio 0.95 [95% CI 0.71-1.27]; one comparison).

    “or all-cause mortality (prevalence ratio 0•95 [95% CI 0•71-1•27]; one comparison)”
    Quote in the paperNot a substantial claim
  • Findingown data

    Interventions promoting handwashing with soap reduced lower respiratory infections (RR 0.78 [95% CI 0.64-0.94], I2 64%; 12 comparisons).

    “Interventions also reduced lower respiratory infections (0•78 [0•64-0•94], I² 64%; 12 comparisons)”
    Quote in the paperSubstantial claim
  • May combine two claims. 20
  • Classified as probably not a substantial claim. 33

  • May combine two claims.

    Findingown data

    26 studies with 161,659 participants met inclusion criteria, providing 27 comparisons (21 randomised).

    “26 studies with 161 659 participants met inclusion criteria, providing 27 comparisons (21 randomised).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    The remaining nine interventions included multiple broader messages (e.g., related to drinking water treatment or mask-wearing).

    “The remaining nine interventions included multiple broader messages (eg, related to drinking water treatment or mask-wearing; table 1).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Only one study reported all-cause mortality, with a prevalence ratio of 0.95 (95% CI 0.71-1.27).

    “No studies meeting the inclusion criteria reported a COVID-19 outcome, and only one reported all-cause mortality (with prevalence ratio of 0•95 [95% CI 0•71-1•27]).46”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    Only two studies reported results by sex.

    “Only two studies reported results by sex.31,32”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Of the 27 interventions included, 18 were conducted in domestic settings and nine in primary school or childcare settings.

    “Of the 27 interventions included in this review, 18 were conducted in domestic settings, and the remaining nine in primary school or childcare settings.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    In our review, we identified 20 randomised studies and six non-randomised studies.

    “In our review, we identified 20 randomised studies and six non-randomised studies.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    For 18 interventions, handwashing with soap was the behavioural target in the majority of intervention messages, of which 14 had it as the exclusive focus.

    “For 18 interventions, handwashing with soap was the behavioural target in the majority of intervention messages, of which 14 had it as the exclusive focus.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    The 26 included studies comprised 161,659 participants, with 13 studies in Asia, nine in Africa, and three in Latin America.

    “The 26 studies included 161 659 participants, with 13 studies in Asia, nine in Africa, and three in Latin America (table 1).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    We reviewed full texts of 45 studies, of which 26 met our inclusion criteria.

    “We reviewed full texts of 45 studies, of which 26 met our inclusion criteria.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The 95% CI for test-confirmed influenza overlaps 1, but our estimate was based on only three comparisons.

    “The 95% CIs for test-confirmed influenza overlaps 1, but our estimate was based on only three comparisons.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    Soap was provided in 16 interventions.

    “Soap was provided in 16 interventions.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Between-study heterogeneity was relatively high by the standards of clinical interventions, and we were able to explain it only partly via metaregression.

    “Between-study heterogeneity was relatively high by the standards of clinical interventions, and we were able to explain it only partly via metaregression.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The RR 95% CIs for lower and upper respiratory infections overlap substantially, and are similar to that for any ARI.

    “The RR 95% CIs for lower and upper respiratory infections overlap substantially, and are similar to that for any ARI (table 2).”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Findingown data

    For the primary outcome (any ARI), we included 27 comparisons from 26 studies, including 21 comparisons from randomised studies and six from non-randomised studies.

    “For the primary outcome (any ARI), we included 27 comparisons from 26 studies-this included 21 comparisons from randomised studies and six from non-randomised studies.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In our lower respiratory infection analysis, five of 12 comparisons were for more objective outcomes (watch-timed rapid respiratory rate), with a similar pooled RR to the primary outcome.

    “In our lower respiratory infection analysis, however, five of 12 comparisons were for more objective outcomes (watch-timed rapid respiratory rate), with a similar pooled RR to the primary outcome.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Aiello and colleagues estimated that hand hygiene improvements reduced ARIs by 21% (95% CI 5-34).

    “who estimated that hand hygiene improvements reduced ARIs by 21% (95% CI 5-34)”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [14] Aiello, 2008, Effect of hand hygiene on infectious disease risk in the community setting: a meta-analysis, Am J Public Health source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    Two of the three influenza studies assessed interventions delivered to household members of a confirmed influenza case, and were probably delivered too late to prevent domestic transmission.

    “Two of these studies 47,48 assessed interventions delivered to household members of a confirmed influenza case, and were probably delivered too late to prevent domestic transmission.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [47] Ram, 2015, Impact of intensive handwashing promotion on secondary household influenza-like illness in rural Bangladesh: findings from a randomized controlled trial, PLoS One source

      Not checked in the free run.

    • cites [48] Simmerman, 2011, Findings from a household randomized controlled trial of hand washing and face masks to reduce influenza transmission in Bangkok, Thailand, Influenza Other Respir Viruses source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    Observed heterogeneity might be partly due to the variety in promotional approaches, follow-up periods, and case definitions.

    “Observed heterogeneity might be partly due to the variety in promotional approaches, follow-up periods, and case definitions.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    ARI-causing pathogens can be transmitted via airborne, surface, or person-to-person contact routes.

    “ARI-causing pathogens can be transmitted via airborne, surface, or person-to-person contact routes.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [7] Fitzner, 2018, Revision of clinical case definitions: influenza-like illness and severe acute respiratory infection, Bull World Health Organ source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Two reviewers independently screened titles, abstracts, and full texts of studies identified during searches.

    “Two reviewers (IR and SB) independently screened titles, abstracts, and full texts of studies identified during searches.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Non-randomised intervention studies with appropriate controls bring an increased risk of bias, but provide a broader view of community-based public health interventions which are challenging to evaluate.

    “Non-randomised intervention studies with appropriate controls bring an increased risk of bias, but provide a broader view of community-based public health interventions which are challenging to evaluate.52”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [52] Rychetnik, 2002, Criteria for evaluating evidence on public health interventions, J Epidemiol Community Health source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductreasoning

    The authors did not attempt to correct standard errors of incorrectly analysed clustered studies (22% of comparisons, n=6), instead accounting for this issue in sensitivity analysis and risk of bias scoring.

    “Therefore, we did not attempt to correct standard errors of incorrectly analysed studies (22% of comparisons, n=6), instead accounting for this issue in sensitivity analysis and risk of bias scoring.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    McGuinness and colleagues' 2017 systematic review focused on ARI in LMICs and included 14 studies.

    “another systematic review conducted in 2017 by McGuinness and colleagues did focus on ARI in LMICs and included 14 studies”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [16] McGuinness, 2018, Effect of hygiene interventions on acute respiratory infections in childcare, school and domestic settings in low- and middle-income countries: a systematic review, Trop Med Int Health source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    A further strength is in distinguishing between lower and upper respiratory infections, which previous handwashing meta-analyses have not done.

    “A further strength is in distinguishing between lower and upper respiratory infections, which previous handwashing meta-analyses have not done.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    Data extraction and risk of bias assessment were performed independently by two reviewers.

    “Data extraction and risk of bias assessment were performed independently by two reviewers (IR and SB) using a structured Excel spreadsheet.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    The overall body of evidence was assessed using a modified GRADE approach.

    “We assessed the body of evidence as a whole for each outcome using a modified GRADE approach.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [34] Schünemann

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Premisenone given

    Masking of participants in handwashing interventions is impossible.

    “First, masking of participants in handwashing interventions is impossible.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    The systematic review and meta-analysis is reported according to PRISMA 2020 guidelines.

    “Our systematic review and meta-analysis is reported according to PRISMA 2020 guidelines.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [18] Page, 2021, The PRISMA 2020 statement: an updated guideline for reporting systematic reviews, BMJ source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    High heterogeneity might also reflect missing influential covariates in multiple studies or measurement error, factors which would also affect the magnitude of effect estimates.

    “Alternatively, high heterogeneity might also reflect missing influential covariates in multiple studies or measurement error, factors which would also affect the magnitude of effect estimates.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The funders had no role in study design, collection and interpretation of data, writing the report, or in the decision to submit for publication.

    “The funders had no role in study design, collection and interpretation of data, writing the report, or in the decision to submit for publication.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Differences between reviewers over screening and full text review were reconciled with a third reviewer.

    “Differences between reviewers over title and abstract screening, full text review, and reasons for exclusion were reconciled with a third reviewer (OC).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The study is registered with PROSPERO, CRD42021231414.

    “This study is registered with PROSPERO, CRD42021231414.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationcitation

    This high heterogeneity might be expected for interventions reliant on uptake and adherence to behaviours, and for studies employing various strategies with different durations and intensities.

    “This high heterogeneity might be expected for interventions reliant on uptake and adherence to behaviours, and for studies employing various strategies with different durations and intensities.53”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [53] Turner, 2012, Predicting the extent of heterogeneity in meta-analysis, using empirical data from the Cochrane Database of Systematic Reviews, Int J Epidemiol source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    A recent systematic review of the effect of handwashing on diarrhoeal disease included ten non-randomised studies.

    “a recent systematic review of the effect of handwashing on diarrhoeal disease included ten non-randomised studies”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [17] Wolf, 2018, Impact of drinking water, sanitation and handwashing with soap on childhood diarrhoeal disease: updated meta-analysis and meta-regression, Trop Med Int Health source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductcitation

    A strength of our study is in using transparent aggregation of different symptoms and case definitions to construct broader outcomes for meta-analysis.

    “A strength of our study is in using transparent aggregation of different symptoms and case definitions to construct broader outcomes for meta-analysis.27”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [27] Borenstein, 2009

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    An LMIC-focused systematic review by McGuinness and colleagues with similar inclusion criteria to ours did not conduct a meta-analysis, but identified 14 randomised studies up to 2017.

    “An LMIC-focused systematic review by McGuinness and colleagues with similar inclusion criteria to ours did not conduct a meta-analysis, but identified 14 randomised studies up to 2017.16”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [16] McGuinness, 2018, Effect of hygiene interventions on acute respiratory infections in childcare, school and domestic settings in low- and middle-income countries: a systematic review, Trop Med Int Health source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Reduced access to water supply on premises or to handwashing facilities with soap and water is a reason for lower handwashing prevalence in LMICs.

    “including reduced access to water supply on premises or to handwashing facilities with soap and water.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [11]

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    Risk of bias in individual studies was assessed using an adapted Newcastle-Ottawa scale.

    “We assessed risk of bias in individual studies using an adapted Newcastle-Ottawa scale applied in previous systematic reviews of the effect of handwashing with soap on diarrhoea.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [17] Wolf, 2018, Impact of drinking water, sanitation and handwashing with soap on childhood diarrhoeal disease: updated meta-analysis and meta-regression, Trop Med Int Health source

      Not checked in the free run.

    • cites [19] Wolf, 2022, Effectiveness of interventions to improve drinking water, sanitation, and handwashing with soap on risk of diarrhoeal disease in children in low-income and middle-income settings: a systematic review and meta-analysis, Lancet source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    I2 statistics were higher than 60% for many meta-analyses within recent Cochrane reviews of interventions such as medical masks to prevent viral illness and indoor residual spraying for malaria.

    “For example, I² statistics were higher than 60% for many meta-analyses within recent Cochrane reviews of interventions such as medical masks to prevent viral illness 12 and indoor residual spraying for malaria.54”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [12] Jefferson, 2020, Physical interventions to interrupt or reduce the spread of respiratory viruses, Cochrane Database Syst Rev

      Not checked in the free run.

    • cites [54] Pryce, 2022, Indoor residual spraying for preventing malaria in communities using insecticide-treated nets, Cochrane Database Syst Rev

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Our estimate for interventions in LMICs is similar in magnitude to the global estimate of Aiello and colleagues (21%) but has greater precision, and is similar to a recent estimate for viral ARI globally (16%).

    “Since our estimate for interventions in LMICs is similar in magnitude to the global estimate of Aiello and colleagues (21%) but has greater precision, 10 and is similar to a recent estimate for viral ARI globally (16%), 12 our results are also applicable to HICs.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [10] Wolf, 2019, Handwashing with soap after potential faecal contact: global, regional and country estimates, Int J Epidemiol source

      Not checked in the free run.

    • cites [12] Jefferson, 2020, Physical interventions to interrupt or reduce the spread of respiratory viruses, Cochrane Database Syst Rev

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Interpretationown data

    Our review suggests that the scarcity of such campaigns might be a missed opportunity, and promoting handwashing with soap more broadly could reduce the large endemic burden of respiratory disease.

    “Our review suggests that the scarcity of such campaigns might be a missed opportunity, and promoting handwashing with soap more broadly could reduce the large endemic burden of respiratory disease.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Handwashing campaigns in normal times are rare.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Limitations of our review processes include that we did not systematically search grey literature, so studies not published in indexed journals might have been omitted.

    “Limitations of our review processes include that we did not systematically search grey literature, so studies not published in indexed journals might have been omitted.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Reporting bias could lead to effects being overstated, but any overestimate might be offset by factors such as less-than-full participation in interventions by the target population (exposure misclassification) or low compliance.

    “Reporting bias could therefore lead to effects being overstated, but any overestimate might be offset by factors such as less-than-full participation in interventions by the target population (ie, exposure misclassification) or low compliance.”
    Quote in the paperNot a substantial claim
43 of 43

  • The paper relies on this without support.

    Handwashing with soap can prevent many ARIs by mechanically removing pathogens from hands, and by rupturing many bacteria and viruses.

    “Handwashing with soap can prevent many ARIs by mechanically removing pathogens from hands, and by rupturing many bacteria and viruses.”

  • The paper relies on this without support.

    There is no biological reason to assume handwashing with soap interrupts transmission of upper and lower respiratory infections differently.

    “There is no biological reason to assume handwashing with soap interrupts transmission of upper and lower respiratory infections differently.”

  • The paper relies on this without support.

    Handwashing campaigns in normal times are rare.

    “However, in comparison with the attention given to handwashing during these epidemics of respiratory disease, handwashing campaigns in normal times are rare.”
3 of 3

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • The exposure-response relationships linking WASH exposure levels and diarrhoea or acute respiratory infections were estimated in two meta-analyses.

    “The exposure–response relationships (figure 1, appendix 1 p 6) linking the different WASH exposure levels (Figure 2, Figure 3, Figure 4) and diarrhoea or acute respiratory infections have been estimated in two meta-analyses.4, 7”

    From Burden of disease attributable to unsafe drinking water, sanitation, and hygiene in domestic settings: a global analysis for selected adverse health outcomes (2023) · cites this paper as [7]

    The Data analysis section says the paper pooled relative risks for acute respiratory infection outcomes, supporting its role as one of the cited meta-analyses. But its comparison is handwashing-with-soap promotion versus no handwashing intervention; our copy does not estimate an exposure–response relationship across different WASH exposure levels. Diarrhoea appears to be the subject of the other citation, not a finding attributed to this paper. (LLM, conf=0.86)

    Experimental — accuracy not yet measured

  • Matching exposure-response relationships are available through up-to-date meta-analyses.

    “and is combined with matching exposure–response relationships available through the up-to-date meta-analyses.4, 7”

    From Burden of disease attributable to unsafe drinking water, sanitation, and hygiene in domestic settings: a global analysis for selected adverse health outcomes (2023) · cites this paper as [7]

    The Data analysis section describes pooling relative risks, and the results (Table 2) report effects of handwashing-promotion interventions versus controls. This supports the availability of an up-to-date meta-analytic effect estimate, but the paper does not provide a graded exposure–response relationship for levels of handwashing exposure. (LLM, conf=0.81)

    Experimental — accuracy not yet measured

  • Respiratory pathogens are transmitted through the air, person-to-person contact, or via surfaces, and handwashing with soap can remove or destroy pathogens on hands, thereby reducing transmission.

    “Respiratory pathogens are transmitted through the air, person-to-person contact, or via surfaces, and handwashing with soap can remove or destroy pathogens on hands, thereby reducing transmission.7”

    From Burden of disease attributable to unsafe drinking water, sanitation, and hygiene in domestic settings: a global analysis for selected adverse health outcomes (2023) · cites this paper as [7]

  • Nationally representative exposure data on safely managed services is available for an increasing number of countries aggregated and published by the JMP.

    “In addition, nationally representative exposure data on safely managed services is available for an increasing number of countries aggregated and published by the JMP”

    From Burden of disease attributable to unsafe drinking water, sanitation, and hygiene in domestic settings: a global analysis for selected adverse health outcomes (2023) · cites this paper as [7]

    The Data availability section describes the review’s meta-analysis data, and the Discussion addresses handwashing interventions and respiratory infections. Neither addresses nationally representative exposure data, safely managed services, or JMP publication; searches for those terms found no supporting passage in our copy. The cited paper therefore does not verify this claim. (LLM, conf=0.76)

    Experimental — accuracy not yet measured

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Search described as using five databases instead of seven

    Minor

    The Results section says five electronic databases were searched, whereas the Methods section names seven.

1 of 1

Cites

Flagged first, then by citations

5 of the 59 references couldn’t be matched to a known paper.

Cited by

Sorted by citations

Related

Authors
Ross, I., Bick, S., Ayieko, P., Dreibelbis, R., Wolf, J., Freeman, M. C., Allen, E., Brauer, M., & Cumming, O.
Affiliations
  • London School of Hygiene & Tropical Medicine (GB)
  • World Health Organization (CH)
  • Emory University (US)
  • University of British Columbia (CA)
Corresponding author
Ross, Ian
ORCID
Venue
The Lancet
Publisher
Elsevier BV
Published
2023-05
Volume
401
Issue
10389
Pages
1681-1690
ISSN
  • 0099-5355 (ISSN-L)
  • 0140-6736
DOI
10.1016/s0140-6736(23)00021-1
OpenAlex
W4367172984
Semantic Scholar
6cf273f3317f32616220f73c4c933e4049f72bd4
Cited by
118
References
59
Citations by year
2026: 42 · 2025: 48 · 2024: 23 · 2023: 5
FWCI
7.55
Type
journal article
Language
en
Open access
Licence
Locations
  • The Lancet (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • LSHTM Research Online (London School of Hygiene and Tropical Medicine) (submittedVersion)
Funders
  • Bill and Melinda Gates Foundation
  • World Health Organization
Topics
  • Health Sciences › Health Professions › Emergency Medical Services › Pediatric health and respiratory diseases
  • Health Sciences › Nursing › Nutrition and Dietetics › Child Nutrition and Water Access
  • Health Sciences › Medicine › Epidemiology › Pneumonia and Respiratory Infections
Keywords
handwashing with soap, hand hygiene, acute respiratory infections, lower respiratory tract infection, upper respiratory tract infection, influenza, COVID-19 pandemic, all-cause mortality, school-based intervention, childcare settings, low- and middle-income countries, infection control, hygiene promotion, children and adolescents, healthcare workers, healthcare facilities, community settings, health care financing
MeSH terms
COVID-19, Developing Countries, Humans, Influenza, Human, Respiratory Tract Infections, Soaps, Pandemics

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-08.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-08.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

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