Response is increased using postal rather than electronic questionnaires - new results from an updated Cochrane Systematic Review.

BACKGROUND: A decade ago paper questionnaires were more common in epidemiology than those administered online, but increasing Internet access may have changed this. Researchers planning to use a self-administered questionnaire should know whether response rates to questionnaires administered electronically differ to those of questionnaires administered by post. We analysed trials included in a recently updated Cochrane Review to answer this question. METHODS: We exported data of randomised controlled trials included in three comparisons in the Cochrane Review that had evaluated hypotheses relevant to our research objective and imported them into Stata for a series of meta-analyses not conducted in the Cochrane review. We pooled odds ratios for response using random effects meta-analyses. We explored causes of heterogeneity among study results using subgroups. We assessed evidence for reporting bias using Harbord's modified test for small-study effects. RESULTS: Twenty-seven trials (66,118 participants) evaluated the effect on response of an electronic questionnaire compared with postal. Results were heterogeneous (I-squared = 98%). There was evidence for biased (greater) effect estimates in studies at high risk of bias; A synthesis of studies at low risk of bias indicates that response was increased (OR = 1.43; 95% CI 1.08-1.89) using postal questionnaires. Ten trials (39,523 participants) evaluated the effect of providing a choice of mode (postal or electronic) compared to an electronic questionnaire only. Response was increased with a choice of mode (OR = 1.63; 95% CI 1.18-2.26). Eight trials (20,909 participants) evaluated the effect of a choice of mode (electronic or postal) compared to a postal questionnaire only. There was no evidence for an effect on response of a choice of mode compared with postal only (OR = 0.94; 95% CI 0.86-1.02). CONCLUSIONS: Postal questionnaires should be used in preference to, or offered in addition to, electronic modes.

Meningococcal carriage among Hajj pilgrims, risk factors for carriage and records of vaccination: a study of pilgrims to Mecca.

OBJECTIVE: The Saudi government requires that all pilgrims receive a quadrivalent meningococcal vaccine at least 10 days before the Hajj. We conducted a study to determine the uptake of meningococcal vaccine and antibiotic use. We also investigated risk factors of meningococcal carriage and carriage of Neisseria meningitidis pathogenic serogroups A, C, W and Y. METHODS: A cross-sectional oropharyngeal carriage survey was conducted in 2973 Hajj pilgrims in September 2017. A real-time polymerase chain reaction (rt-PCR) assay was used to identify N. meningitidis from the oropharyngeal swabs. A questionnaire investigated potential risk factors for carriage of N. meningitidis. RESULTS: Two thousand two hundred forty nine oropharyngeal swabs were obtained. The overall prevalence of carriage of N. meningitidis was 4.6% (95% CI: 3.4%-6%). Carriage of pathogenic serogroups was not associated significantly with any of the meningococcal risk factors evaluated. 77% of pilgrims were vaccinated but 22.58 % said they were carrying unofficial vaccination cards. CONCLUSION: Carriage of serogroups A, C, W and Y was not significantly associated with any of the risk factors investigated. Almost a quarter of pilgrims were unlikely to have been vaccinated, highlighting a need to strengthen compliance with the current policy of vaccination to prevent meningococcal disease outbreaks during and after the Hajj.

Does pre-notification increase questionnaire response rates: a randomised controlled trial nested within a systematic review.

BACKGROUND: Missing outcome data can lead to bias in the results of systematic reviews. One way to address missing outcome data is by requesting the data from the trial authors, but non-response is common. One way to potentially improve response rates is by sending study participants advance communication. During the update of a systematic review examining the effect of pre-notification on response rates, study authors needed to be contacted for further information. This study was nested within the systematic review by randomising authors to receive a notification of the upcoming request for information. The objective was to test if pre-notification increased response rates. METHODS: The participants were study authors included in the systematic review, whose studies were at unclear risk of bias. The intervention was a pre-notification of the request for further information, sent 1 day before the request. The outcome was defined as the proportion of authors who responded to the request for information. Authors were randomised by simple randomisation. Thirty three authors were randomised to the pre-notification arm, and 42 were randomised to the control arm. Authors were blinded to the possibility of an alternative condition. RESULTS: All authors randomised were analysed. 14/33 (42.4%) authors in the pre-notification arm had returned responses to the questionnaire, and 18/42 (42.9%) in the control arm. There was no evidence of a difference between these groups (absolute difference = - 0.5, 95% CI (- 23.4 to 22.5%), p = 1). We received no complaints about receiving the pre-notification. CONCLUSIONS: This study's results do not support the hypothesis that pre-notification increases response from study authors being contacted for a request for more information. However, the study has a low power, and the results may not generalise to other contexts, methods of administering a pre-notification, or study populations. TRIAL REGISTRATION: Registration and protocol: This trial is not registered with any trial registry. However, the protocol was posted in advance on the Open Science Framework website and is available on the Open Science Framework website: DOI: https://doi.org/10.17605/OSF.IO/MSV2W or https://osf.io/msv2w/.

Does advance contact with research participants increase response to questionnaires: an updated systematic review and meta-analysis.

BACKGROUND: Questionnaires remain one of the most common forms of data collection in epidemiology, psychology and other human-sciences. However, results can be badly affected by non-response. One way to potentially reduce non-response is by sending potential study participants advance communication. The last systematic review to examine the effect of questionnaire pre-notification on response is 10 years old, and lacked a risk of bias assessment. OBJECTIVES: Update the section of the Cochrane systematic review, Edwards et al. (2009), on pre-notification to include 1) recently published studies, 2) an assessment of risk of bias, 3) Explore if heterogeneity is reduced by: delay between pre-contact and questionnaire delivery, the method of pre-contact, if pre-contact and questionnaire delivery differ, if the pre-contact includes a foot-in-the-door manipulation, and study's the risk of bias. METHODS: Inclusion criteria: population: any population, intervention: comparison of some type of pre-notification, comparison group: no pre-notification, outcome: response rates. STUDY DESIGN: randomised controlled trails. EXCLUSION CRITERIA: NA. DATA SOURCES: Studies which cited or were included in Edwards et al. (2009); We additionally searched: CINAHL, Web of Science, PsycInfo, MEDLINE, EconLit, EMBASE, Cochrane Central, Cochrane CMR, ERIC, and Sociological Abstracts. The searches were implemented in June 2018 and May 2021. Study screening: a single reviewer screened studies, with a random 10% sample independently screened to ascertain accuracy. DATA EXTRACTION: data was extracted by a single reviewer twice, with a week between each extraction. Risk of Bias: within studies bias was assessed using the Cochrane Risk of Bias tool (ROB1) by a single unblinded reviewer, across studies bias was assessed using funnel plots. Synthesis Method: study results were meta-analysed with a random effects model using the final response rate as the outcome. Evaluation of Uncertainty: Uncertainty was evaluated using the GRADE approach. RESULTS: One hundred seven trials were included with 211,802 participants. Over-all pre-notification increased response, OR = 1.33 (95% CI: 1.20-1.47). However, there was a large amount of heterogeneity (I2 = 97.1%), which was not explained by the subgroup analyses. In addition, when studies at high or unclear risk of bias were excluded the effect was to reduced OR = 1.09 (95% CI: 0.99-1.20). Because of the large amount of heterogeneity, even after restricting to low risk of bias studies, there is still moderate uncertainty in these results. CONCLUSIONS: Using the GRADE evaluation, this review finds moderate evidence that pre-notification may not have an effect on response rates. FUNDING: Economic and Social Research Council. PREREGISTRATION: None.

The incidence of construction site injuries to women in Delhi: capture-recapture study.

BACKGROUND: In India, the construction sector provides the main alternative to agricultural work - seasonal migration to and from construction work is widespread and construction work remains the second-largest employer of women in the country behind agriculture. Occupational injuries, which kill over 300,000 people annually, are a serious public health concern. However, data on construction site injuries to women are lacking, as India does not publish statistics on occupational injuries and illnesses. Our objectives were to: Estimate the number of women injured in construction site accidents in Delhi; and to estimate and compare the annual construction site injury rates per 100,000 workers of males and females in Delhi. METHODS: We conducted a two-sample capture-recapture study using data for accidents reported to the Delhi Police, Employee State Insurance Corporation (ESIC), and Commissioners of Workmen Compensation (CWC) of Delhi Government. The capture-recapture method has been used in epidemiology, to estimate morbidity and mortality using multiple, overlapping, but incomplete data sources. This study is based on the injuries reported from construction site accidents in Delhi in 2017. We linked the data from each of the data sources using the name, gender, and age of each injured person, the date and place of the accident, and the name of the employer. We used the Chapman estimator to estimate the total incidence of construction injuries in Delhi. RESULTS: We estimated that there was a total of 37 female construction site workers injured (17 fatal and 20 non-fatal) in Delhi in 2017. There was a total of 1043 male construction site workers injured (236 fatal and 807 non-fatal). FIRs ascertained two-thirds (68%) of all injuries to females but only one third (34%) of those to males. The annual construction site injury rate per 100,000 workers of females was 82.26 (95%CI: 57.92 to 113.39). The annual construction site injury rate per 100,000 workers of males was 146.5 (95%CI: 137.7 to 155.6). There was strong evidence (p = 0.001) that the overall construction site injury rate per 100,000 workers of females was about one half the rate of males [rate ratio 0.56 (95%CI: 0.40 to 0.78)]. There was no evidence (p = 0.601) that the rates of fatal injuries differed in males and females (rate ratio 1.14 (95%CI: 0.70 to 1.87). CONCLUSIONS: This study is the first to estimate the incidence of injuries to female construction site workers in India. The overall injury rate of female construction workers was over half as great as the rate of males. This implies that female construction workers face a not insignificant risk. Hence, safety measures (e.g., personal protective equipment) that are appropriate and culturally acceptable to Indian women are needed.

Evaluation of first information reports of Delhi police for injury surveillance: Data extraction tool development & validation.

BACKGROUND & OBJECTIVES: : Policymakers and health professionals need to know the distribution, patterns, trends and risk factors of injury occurrence to develop strategies that reduce the incidence of injuries. The first information report (FIR) of Indian police is one potential source of this information. The aims of this study were to identify the minimum data set (MDS) recommended for injury surveillance, to develop a tool for data extraction from FIRs, to evaluate whether FIRs contain this MDS and to assess the inter-rater reliability of the tool. METHODS: : This was a cross-sectional study of incidents reported to Delhi Police in 2017. A systematic literature search was conducted to identify the MDS recommended for injury surveillance. A tool was designed for extraction of data, and its inter-rater reliability was assessed using Cohen's kappa and the percentage availability of each MDS data item in the FIRs, was calculated. RESULTS: : The literature review identified 24 reports that recommended 12 MDS for injury surveillance. The FIRs contained complete information on the following five MDS: sex/gender (100%), date of injury (100%), time of injury (100%), place of injurious event (100%) and intent (100%). For the following seven MDS, information was not complete: name (93.1%), age (67.2%), occupation (32.8%), residence (86.2%), activity of the injured person (86.2%), cause of the injury (93.1%) and nature of the injury (41.4%). The inter-rater reliability of the data extraction tool was found to be almost perfect. INTERPRETATION & CONCLUSIONS: : Information on injuries can be reliably extracted from FIRs. Although FIRs do not always contain complete information on the MDS, if missing data are imputed, these could form the basis of an injury surveillance system. However, use of FIRs for injury surveillance could be limited by the representativeness of injuries ascertained by FIRs to the population. FIRs thus have the potential to become an important component of an integrated injury surveillance system.

An Intervention Delivered by Mobile Phone Instant Messaging to Increase Acceptability and Use of Effective Contraception Among Young Women in Bolivia: Randomized Controlled Trial.

BACKGROUND: Although the most effective methods of contraception are available in Bolivia, unmet need for contraception among women aged 15 to 19 years is estimated to be 38% (2008), and the adolescent fertility rate is 71 per 1000 women (2016). Mobile phones are a popular mode to deliver health behavior support. We developed a contraceptive behavioral intervention for young Bolivian women delivered by mobile phone and guided by behavioral science. The intervention consists of short instant messages sent through an app over 4 months. OBJECTIVE: This trial aimed to evaluate the effect of the intervention on young Bolivian women's use of and attitudes toward the effective contraceptive methods available in Bolivia. METHODS: This was a parallel group, individually randomized superiority trial with a 1:1 allocation ratio. Women were eligible if they were aged 16 to 24 years, owned a personal Android mobile phone, lived in La Paz or El Alto, reported an unmet need for contraception, and could read Spanish. The target sample size was 1310 participants. Participants allocated to the intervention had access to an app with standard family planning information and intervention messages. Participants allocated to the control group had access to the same app and control messages. Coprimary outcomes were use of effective contraception and acceptability of at least one method of effective contraception at 4 months. Secondary outcomes were use of effective contraception during the study, acceptability of the individual methods, service uptake, unintended pregnancy, and abortion. Process outcomes included knowledge, perceived norms, personal agency, and intention. Outcomes were analyzed using logistic and linear regression. We also asked participants about physical violence. RESULTS: A total of 640 participants were enrolled, and 67.0% (429) of them contributed follow-up data for the coprimary outcome, the use of effective contraception. There was no evidence that use differed between the groups (33% control vs 37% intervention; adjusted odds ratio [OR] 1.19, 95% CI 0.80 to 1.77; P=.40). There was a borderline significant effect regarding acceptability (63% control vs 72% intervention; adjusted OR 1.49, 95% CI 0.98 to 2.28; P=.06). There were no statistically significant differences in any of the secondary or process outcomes. The intervention dose received was low. In the control group, 2.8% (6/207) reported experiencing physical violence compared with 1.9% (4/202) in the intervention group (Fisher exact test P=.75). CONCLUSIONS: This trial was unable to provide definitive conclusions regarding the effect of the intervention on use and acceptability of effective contraception because of under recruitment. Although we cannot strongly recommend implementation, the results suggest that it would be safe and may increase the acceptability of effective contraception if the intervention messages were offered alongside the download of the app. TRIAL REGISTRATION: ClinicalTrials.gov NCT02905526; https://clinicaltrials.gov/ct2/show/NCT02905526.

Sedentary behaviour and risk of all-cause, cardiovascular and cancer mortality, and incident type 2 diabetes: a systematic review and dose response meta-analysis.

PURPOSE:  To estimate the strength and shape of the dose-response relationship between sedentary behaviour and all-cause, cardiovascular disease (CVD) and cancer mortality, and incident type 2 diabetes (T2D), adjusted for physical activity (PA). Data Sources: Pubmed, Web of Knowledge, Medline, Embase, Cochrane Library and Google Scholar (through September-2016); reference lists. Study Selection: Prospective studies reporting associations between total daily sedentary time or TV viewing time, and ≥ one outcome of interest. Data Extraction: Two independent reviewers extracted data, study quality was assessed; corresponding authors were approached where needed. Data Synthesis: Thirty-four studies (1,331,468 unique participants; good study quality) covering 8 exposure-outcome combinations were included. For total sedentary behaviour, the PA-adjusted relationship was non-linear for all-cause mortality (RR per 1 h/day: were 1.01 (1.00-1.01) ≤ 8 h/day; 1.04 (1.03-1.05) > 8 h/day of exposure), and for CVD mortality (1.01 (0.99-1.02) ≤ 6 h/day; 1.04 (1.03-1.04) > 6 h/day). The association was linear (1.01 (1.00-1.01)) with T2D and non-significant with cancer mortality. Stronger PA-adjusted associations were found for TV viewing (h/day); non-linear for all-cause mortality (1.03 (1.01-1.04) ≤ 3.5 h/day; 1.06 (1.05-1.08) > 3.5 h/day) and for CVD mortality (1.02 (0.99-1.04) ≤ 4 h/day; 1.08 (1.05-1.12) > 4 h/day). Associations with cancer mortality (1.03 (1.02-1.04)) and T2D were linear (1.09 (1.07-1.12)). CONCLUSIONS:  Independent of PA, total sitting and TV viewing time are associated with greater risk for several major chronic disease outcomes. For all-cause and CVD mortality, a threshold of 6-8 h/day of total sitting and 3-4 h/day of TV viewing was identified, above which the risk is increased.

Assessing the validity and reliability of self-report data on contraception use in the MObile Technology for Improved Family Planning (MOTIF) randomised controlled trial.

BACKGROUND: A variety of different approaches to measuring contraceptive use have been used or proposed, either to assess current use or adherence over time, using subjective or objective measures. This paper reports an overview of approaches to measuring adherence to the oral contraceptive, intra-uterine device, sub-dermal implant, and injectable and describes how we assessed contraception use in the MObile Technology for Improved Family Planning (MOTIF) trial in Cambodia. MAIN BODY: We summarise and discuss advantages and disadvantages of different subjective and objective approaches to measuring adherence to the oral contraceptive, intra-uterine device, sub-dermal implant, and injectable such as self-reports, clinic records, electronic monitoring devices, clinical examination and biomarkers. For the MOTIF trial, we did not consider it feasible to measure objective contraception use as many participants lived a long distance from the clinic and we were concerned whether it was appropriate to ask women to return to clinic for a physical examination simply to verify self-report information already provided. We aimed to assess the validity of the four-month data with 50 participants, calculating the sensitivity and specificity of self-reported data compared with objective measurement. For the 46 valid measurements obtained, the sensitivity and specificity was 100% for self-reported contraception use compared to objective measurement but this study had some limitations. To assess reliability of self-report data we compared calendar data collected on effective contraception use at months 1-4 post-abortion, collected separately at four and 12 months. Agreement ranged from 80 to 84% with a kappa statistic ranging from 0·59 to 0·67 indicating fair to good agreement. CONCLUSION: There is no perfect method of assessing contraception use and researchers designing future studies should give consideration of what to measure, for example current use or detailed patterns of use over time, and remain mindful of what will be feasible and acceptable to the study population. Although self-reported data on contraception use are considered less reliable, and prone to social desirability bias, it is often the standard approach for contraception research and provides data comparable to previous studies. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01823861 . Registered: March 30, 2013.

A randomized controlled trial of an intervention delivered by mobile phone app instant messaging to increase the acceptability of effective contraception among young people in Tajikistan.

BACKGROUND: Unintended pregnancy is associated with poorer health outcomes for women and their families. In Tajikistan, around 26% of married 15-24 year old women have an unmet need for contraception. There is some evidence that interventions delivered by mobile phone can affect contraceptive-related behaviour and knowledge. We developed an intervention delivered by mobile phone app instant messaging to improve acceptability of effective contraceptive methods among young people in Tajikistan. METHODS: This was a randomized controlled trial among Tajik people aged 16-24. Participants allocated to the intervention arm had access to an app plus intervention messages. Participants allocated to the control arm had access to the app plus control messages. The primary outcome was acceptability of at least one method of effective contraception at 4 months. Secondary outcomes were use of effective contraception at 4 months and during the study, acceptability of individual methods, service uptake, unintended pregnancy and induced abortion. Process outcomes were knowledge, perceived norms, personal agency and intention. Outcomes were analysed using logistic and linear regression. We conducted a pre-specified subgroup analysis and a post-hoc analysis of change in acceptability from baseline to follow-up. RESULTS: Five hundred and seventy-three participants were enrolled. Intervention content was included on the app, causing contamination. Four hundred and seventy-two (82%) completed follow-up for the primary outcome. There was no evidence of a difference in acceptability of effective contraception between the groups (66% in the intervention arm vs 64% in the control arm, adjusted OR 1.21, 95% CI .80-1.83, p = 0.36). There were no differences in the secondary or process outcomes between groups. There was some evidence that the effect of the intervention was greater among women compared to men (interaction test p = 0.03). There was an increase in acceptability of effective contraception from baseline to follow-up (2% to 65%, p < 0.001). CONCLUSIONS: The whole intervention delivered by instant messaging provided no additional benefit over a portion of the intervention delivered by app pages. The important increase in contraceptive acceptability from baseline to follow-up suggests that the intervention content included on the app may influence attitudes. Further research is needed to establish the effect of the intervention on attitudes towards and use of effective contraception among married/sexually active young people. TRIAL REGISTRATION: Clinicaltrial.gov NCT02905513 . Date of registration: 14 September 2016.

Correction to: A randomized controlled trial of an intervention delivered by mobile phone app instant messaging to increase the acceptability of effective contraception among young people in Tajikistan.

After publication of the original article [1], it came to the authors' attention that there is a typo in the Results section.

Is ethnic density associated with risk of child pedestrian injury? A comparison of inter-census changes in ethnic populations and injury rates.

OBJECTIVES: Research on inequalities in child pedestrian injury risk has identified some puzzling trends: although, in general, living in more affluent areas protects children from injury, this is not true for those in some minority ethnic groups. This study aimed to identify whether 'group density' effects are associated with injury risk, and whether taking these into account alters the relationship between area deprivation and injury risk. 'Group density' effects exist when ethnic minorities living in an area with a higher proportion of people from a similar ethnic group enjoy better health than those who live in areas with a lower proportion, even though areas with dense minority ethnic populations can be relatively more materially disadvantaged. DESIGN: This study utilised variation in minority ethnic densities in London between two census periods to identify any associations between group density and injury risk. Using police data on road traffic injury and population census data from 2001 to 2011, the numbers of 'White,' 'Asian' and 'Black' child pedestrian injuries in an area were modelled as a function of the percentage of the population in that area that are 'White,' 'Asian' and 'Black,' controlling for socio-economic disadvantage and characteristics of the road environment. RESULTS: There was strong evidence (p < 0.001) of a negative association between 'Black' population density and 'Black' child pedestrian injury risk [incidence (of injury) rate ratios (IRR) 0.575, 95% CI 0.515-0.642]. There was weak evidence (p = 0.083) of a negative association between 'Asian' density and 'Asian' child pedestrian injury risk (IRR 0.901, 95% CI 0.801-1.014) and no evidence (p = 0.412) of an association between 'White' density and 'White' child pedestrian injury risk (IRR 1.075, 95% CI 0.904-1.279). When group density effects are taken into account, area deprivation is associated with injury risk of all ethnic groups. CONCLUSIONS: Group density appears to protect 'Black' children living in London against pedestrian injury risk. These findings suggest that future research should focus on structural properties of societies to explain the relationships between minority ethnicity and risk.

Effect of a mobile phone-based intervention on post-abortion contraception: a randomized controlled trial in Cambodia.

OBJECTIVE: To assess the effect of a mobile phone-based intervention (mHealth) on post-abortion contraception use by women in Cambodia. METHODS: The Mobile Technology for Improved Family Planning (MOTIF) study involved women who sought safe abortion services at four Marie Stopes International clinics in Cambodia. We randomly allocated 249 women to a mobile phone-based intervention, which comprised six automated, interactive voice messages with counsellor phone support, as required, whereas 251 women were allocated to a control group receiving standard care. The primary outcome was the self-reported use of an effective contraceptive method, 4 and 12 months after an abortion. FINDINGS: Data on effective contraceptive use were available for 431 (86%) participants at 4 months and 328 (66%) at 12 months. Significantly more women in the intervention than the control group reported effective contraception use at 4 months (64% versus 46%, respectively; relative risk, RR: 1.39; 95% confidence interval, CI: 1.17-1.66) but not at 12 months (50% versus 43%, respectively; RR: 1.16; 95% CI: 0.92-1.47). However, significantly more women in the intervention group reported using a long-acting contraceptive method at both follow-up times. There was no significant difference between the groups in repeat pregnancies or abortions at 4 or 12 months. CONCLUSION: Adding a mobile phone-based intervention to abortion care services in Cambodia had a short-term effect on the overall use of any effective contraception, while the use of long-acting contraceptive methods lasted throughout the study period.

Development and validation of a self-administered questionnaire to estimate the distance and mode of children's travel to school in urban India.

BACKGROUND: Although some 300 million Indian children travel to school every day, little is known about how they get there. This information is important for transport planners and public health authorities. This paper presents the development of a self-administered questionnaire and examines its reliability and validity in estimating distance and mode of travel to school in a low resource urban setting. METHODS: We developed a questionnaire on children's travel to school. We assessed test re-test reliability by repeating the questionnaire one week later (n = 61). The questionnaire was improved and re-tested (n = 68). We examined the convergent validity of distance estimates by comparing estimates based on the nearest landmark to children's homes with a 'gold standard' based on one-to-one interviews with children using detailed maps (n = 50). RESULTS: Most questions showed fair to almost perfect agreement. Questions on usual mode of travel (κ 0.73- 0.84) and road injury (κ 0.61- 0.72) were found to be more reliable than those on parental permissions (κ 0.18- 0.30), perception of safety (κ 0.00- 0.54), and physical activity (κ -0.01- 0.07). The distance estimated by the nearest landmark method was not significantly different than the in-depth method for walking , 52 m [95 % CI -32 m to 135 m], 10 % of the mean difference, and for walking and cycling combined, 65 m [95 % CI -30 m to 159 m], 11 % of the mean difference. For children who used motorized transport (excluding private school bus), the nearest landmark method under-estimated distance by an average of 325 metres [95 % CI -664 m to 1314 m], 15 % of the mean difference. CONCLUSIONS: A self-administered questionnaire was found to provide reliable information on the usual mode of travel to school, and road injury, in a small sample of children in Hyderabad, India. The 'nearest landmark' method can be applied in similar low-resource settings, for a reasonably accurate estimate of the distance from a child's home to school.

Contribution of food sources to the vitamin B12 status of South Indian children from a birth cohort recruited in the city of Mysore.

OBJECTIVE: There is evidence that subclinical vitamin B12 (B12) deficiency is common in India. Vegetarianism is prevalent and therefore meat consumption is low. Our objective was to explore the contribution of B12-source foods and maternal B12 status during pregnancy to plasma B12 concentrations. DESIGN: Maternal plasma B12 concentrations were measured during pregnancy. Children's dietary intakes and plasma B12 concentrations were measured at age 9.5 years; B12 and total energy intakes were calculated using food composition databases. We used linear regression to examine associations between maternal B12 status and children's intakes of B12 and B12-source foods, and children's plasma B12 concentrations. SETTING: South Indian city of Mysore and surrounding rural areas. SUBJECTS: Children from the Mysore Parthenon Birth Cohort (n 512, 47.1 % male). RESULTS: Three per cent of children were B12 deficient (<150 pmol/l). A further 14 % had 'marginal' B12 concentrations (150-221 pmol/l). Children's total daily B12 intake and consumption frequencies of meat and fish, and micronutrient-enriched beverages were positively associated with plasma B12 concentrations (P=0.006, P=0.01 and P=0.04, respectively, adjusted for socio-economic indicators and maternal B12 status). Maternal pregnancy plasma B12 was associated with children's plasma B12 concentrations, independent of current B12 intakes (P<0.001). Milk and curd (yoghurt) intakes were unrelated to B12 status. CONCLUSIONS: Meat and fish are important B12 sources in this population. Micronutrient-enriched beverages appear to be important sources in our cohort, but their high sugar content necessitates care in their recommendation. Improving maternal B12 status in pregnancy may improve Indian children's status.

Central and statistical data monitoring in the Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage (CRASH-2) trial.

Background The purpose of monitoring in clinical trials is to ensure the rights, safety, and well-being of trial patients and the accuracy of the trial data. In the Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage (CRASH-2) trial, which recruited over 20,000 adult trauma patients worldwide, the nature and extent of monitoring was based on a risk assessment undertaken before recruitment started. Purpose We report the methods used for central and statistical monitoring in the CRASH-2 trial and explain how central monitoring was used to target on-site investigations. Methods To ensure that trial participants met the inclusion criteria, we monitored event rates for the primary (death) and secondary outcomes (blood transfusion given). We monitored four quantitative variables (systolic blood pressure (SBP), heart rate (HR), respiratory rate, and capillary refill time) as indicators of the severity of bleeding. We used the coefficient of variation (CV) to identify sites with too much or too little variability. To ensure the accuracy of the data on side effects, we monitored thromboembolic events at each site. Sites with higher or lower than expected event rates were identified for further evaluation. Results A total of 274 sites recruited patients: 145 sites recruited ≥20; patients, and 52 sites recruited ≥100 patients. Sites with low case fatality and low blood transfusion rates were found to be including patients with relatively mild haemorrhage. One site with a high rate of thromboembolic events was found to be using clinical judgement alone. Measurements of SBP and HR varied by about one-fifth of their average value, and capillary refill time measurements varied by around one-third of their average; between-site variation was lowest for blood pressure. Limitations A comparison of mean and median CV indicated that the distributions are slightly skewed to the right. Our simple approach to calculating 95% confidence intervals for the CV may be improved by using a logarithmic transformation of CV for each variable. Conclusions Central and statistical monitoring of data can be used to monitor clinical trials, particularly large, pragmatic, international trials where 100% on-site monitoring is neither necessary nor cost-effective. In the CRASH-2 trial, re-education about trial protocol and the development of guidance helped resolve the issues identified during monitoring.

Controlling for exposure changes the relationship between ethnicity, deprivation and injury: an observational study of child pedestrian injury rates in London.

BACKGROUND: Research has suggested that inequalities in risk exposure may help explain identified ethnic inequalities in child pedestrian injury risk. However, addressing risk exposure in epidemiological research presents theoretical and methodological challenges. This article conceptualises the risk of child pedestrian injury as related to both exposure levels (the quantity of time children spend as pedestrians) and the probability of a hazard where that exposure takes place (the quality of the road environment). OBJECTIVE: To investigate the sensitivity of results on ethnic inequalities in child pedestrian injury risk in London to control for exposure and hazard levels. METHODS: Using police records of injury 2000-2009, we modelled the relationship between ethnicity, deprivation and child pedestrian injury rates in London using characteristics of the road environment to control for hazard levels and restricting the analysis to the time of the weekday morning commute (7.00-9.00 am), when most children must make a journey to school, to control for exposure levels. RESULTS: Controlling for risk exposure in this way fundamentally changed the nature of the relationship between ethnicity, deprivation and child pedestrian injury. During the time of the morning commute to school, 'Black' children were found to have higher pedestrian injury rates in the least-deprived areas. CONCLUSIONS: To inform effective strategies for reducing injury inequality, it is vital that exposure to risk is both acknowledged and considered.

Pedestrian safety on the road to net zero: cross-sectional study of collisions with electric and hybrid-electric cars in Great Britain.

BACKGROUND: Plans to phase out fossil fuel-powered internal combustion engine (ICE) vehicles and to replace these with electric and hybrid-electric (E-HE) vehicles represent a historic step to reduce air pollution and address the climate emergency. However, there are concerns that E-HE cars are more hazardous to pedestrians, due to being quieter. We investigated and compared injury risks to pedestrians from E-HE and ICE cars in urban and rural environments. METHODS: We conducted a cross-sectional study of pedestrians injured by cars or taxis in Great Britain. We estimated casualty rates per 100 million miles of travel by E-HE and ICE vehicles. Numerators (pedestrians) were extracted from STATS19 datasets. Denominators (car travel) were estimated by multiplying average annual mileage (using National Travel Survey datasets) by numbers of vehicles. We used Poisson regression to investigate modifying effects of environments where collisions occurred. RESULTS: During 2013-2017, casualty rates per 100 million miles were 5.16 (95% CI 4.92 to 5.42) for E-HE vehicles and 2.40 (95%CI 2.38 to 2.41) for ICE vehicles, indicating that collisions were twice as likely (RR 2.15; 95% CI 2.05 to 2.26) with E-HE vehicles. Poisson regression found no evidence that E-HE vehicles were more dangerous in rural environments (RR 0.91; 95% CI 0.74 to 1.11); but strong evidence that E-HE vehicles were three times more dangerous than ICE vehicles in urban environments (RR 2.97; 95% CI 2.41 to 3.7). Sensitivity analyses of missing data support main findings. CONCLUSION: E-HE cars pose greater risk to pedestrians than ICE cars in urban environments. This risk must be mitigated as governments phase out petrol and diesel cars.

Silence is golden, but my measures still see-why cheaper-but-noisier outcome measures in large simple trials can be more cost-effective than gold standards.

OBJECTIVE: To assess the cost-effectiveness of using cheaper-but-noisier outcome measures, such as a short questionnaire, for large simple clinical trials. BACKGROUND: To detect associations reliably, trials must avoid bias and random error. To reduce random error, we can increase the size of the trial and increase the accuracy of the outcome measurement process. However, with fixed resources, there is a trade-off between the number of participants a trial can enrol and the amount of information that can be collected on each participant during data collection. METHODS: To consider the effect on measurement error of using outcome scales with varying numbers of categories, we define and calculate the variance from categorisation that would be expected from using a category midpoint; define the analytic conditions under which such a measure is cost-effective; use meta-regression to estimate the impact of participant burden, defined as questionnaire length, on response rates; and develop an interactive web-app to allow researchers to explore the cost-effectiveness of using such a measure under plausible assumptions. RESULTS: An outcome scale with only a few categories greatly reduced the variance of non-measurement. For example, a scale with five categories reduced the variance of non-measurement by 96% for a uniform distribution. We show that a simple measure will be more cost-effective than a gold-standard measure if the relative increase in variance due to using it is less than the relative increase in cost from the gold standard, assuming it does not introduce bias in the measurement. We found an inverse power law relationship between participant burden and response rates such that a doubling the burden on participants reduces the response rate by around one third. Finally, we created an interactive web-app ( https://benjiwoolf.shinyapps.io/cheapbutnoisymeasures/ ) to allow exploration of when using a cheap-but-noisy measure will be more cost-effective using realistic parameters. CONCLUSION: Cheaper-but-noisier questionnaires containing just a few questions can be a cost-effective way of maximising power. However, their use requires a judgement on the trade-off between the potential increase in risk of information bias and the reduction in the potential of selection bias due to the expected higher response rates.

The effectiveness of mobile-health technologies to improve health care service delivery processes: a systematic review and meta-analysis.

BACKGROUND: Mobile health interventions could have beneficial effects on health care delivery processes. We aimed to conduct a systematic review of controlled trials of mobile technology interventions to improve health care delivery processes. METHODS AND FINDINGS: We searched for all controlled trials of mobile technology based health interventions using MEDLINE, EMBASE, PsycINFO, Global Health, Web of Science, Cochrane Library, UK NHS HTA (Jan 1990-Sept 2010). Two authors independently extracted data on allocation concealment, allocation sequence, blinding, completeness of follow-up, and measures of effect. We calculated effect estimates and we used random effects meta-analysis to give pooled estimates. We identified 42 trials. None of the trials had low risk of bias. Seven trials of health care provider support reported 25 outcomes regarding appropriate disease management, of which 11 showed statistically significant benefits. One trial reported a statistically significant improvement in nurse/surgeon communication using mobile phones. Two trials reported statistically significant reductions in correct diagnoses using mobile technology photos compared to gold standard. The pooled effect on appointment attendance using text message (short message service or SMS) reminders versus no reminder was increased, with a relative risk (RR) of 1.06 (95% CI 1.05-1.07, I(2) = 6%). The pooled effects on the number of cancelled appointments was not significantly increased RR 1.08 (95% CI 0.89-1.30). There was no difference in attendance using SMS reminders versus other reminders (RR 0.98, 95% CI 0.94-1.02, respectively). To address the limitation of the older search, we also reviewed more recent literature. CONCLUSIONS: The results for health care provider support interventions on diagnosis and management outcomes are generally consistent with modest benefits. Trials using mobile technology-based photos reported reductions in correct diagnoses when compared to the gold standard. SMS appointment reminders have modest benefits and may be appropriate for implementation. High quality trials measuring clinical outcomes are needed. Please see later in the article for the Editors' Summary.