All authors have read the journal's policy and have declared that no competing interests exist.
¶ Membership of the VBI Research Team is provided in the Acknowledgments.
The majority of people do not achieve recommended levels of physical activity. There is a need for effective, scalable interventions to promote activity. Self-monitoring by pedometer is a potentially suitable strategy. We assessed the effectiveness and cost-effectiveness of a very brief (5-minute) pedometer-based intervention (‘Step It Up’) delivered as part of National Health Service (NHS) Health Checks in primary care.
The Very Brief Intervention (VBI) Trial was a two parallel-group, randomised controlled trial (RCT) with 3-month follow-up, conducted in 23 primary care practices in the East of England.
Participants were 1,007 healthy adults aged 40 to 74 years eligible for an NHS Health Check. They were randomly allocated (1:1) using a web-based tool between October 1, 2014, and December 31, 2015, to either intervention (505) or control group (502), stratified by primary care practice. Participants were aware of study group allocation. Control participants received the NHS Health Check only. Intervention participants additionally received Step It Up: a 5-minute face-to-face discussion, written materials, pedometer, and step chart. The primary outcome was accelerometer-based physical activity volume at 3-month follow-up adjusted for sex, 5-year age group, and general practice. Secondary outcomes included time spent in different intensities of physical activity, self-reported physical activity, and economic measures. We conducted an in-depth fidelity assessment on a subsample of Health Check consultations.
Participants’ mean age was 56 years, two-thirds were female, they were predominantly white, and two-thirds were in paid employment. The primary outcome was available in 859 (85.3%) participants. There was no significant between-group difference in activity volume at 3 months (adjusted intervention effect 8.8 counts per minute [cpm]; 95% CI −18.7 to 36.3;
In this large well-conducted trial, we found no evidence of effect of a plausible very brief pedometer intervention embedded in NHS Health Checks on objectively measured activity at 3-month follow-up.
Current Controlled Trials (
Wendy Hardeman and colleagues investigate a short physical activity intervention in a randomized controlled trial.
Systematic reviews support the effectiveness and cost-effectiveness of brief (up to 30 minutes) physical activity interventions in primary care and the effectiveness of intensive pedometer interventions.
There is a need for briefer interventions in primary care, where time is limited but potential reach is large.
However, the reviews show uncertainty about the effectiveness and cost-effectiveness of very brief (up to 5 minutes) interventions in primary care.
Until now, there have been no randomised controlled trials (RCTs) of a very brief pedometer-based intervention to increase physical activity in primary care.
We randomly assigned participants who attended preventive health checks in primary care (National Health Service [NHS] Health Checks) to the health check alone or additionally a very brief pedometer-based physical activity intervention delivered by practice nurses or healthcare assistants. We measured physical activity objectively at 3 months after the intervention.
Our large trial found no benefit of a very brief physical activity intervention in the context of preventive health checks in primary care.
Despite the intervention being apparently simple and very brief, fidelity of delivery was suboptimal. Trial participants were more active than might have been expected.
The economic evaluation shows a small added cost for a small and uncertain benefit.
The absence of a positive effect of a very brief physical activity intervention challenges the commissioning of such interventions in this context.
Primary care practitioners should continue to opportunistically provide very brief advice about physical activity.
The global prevalence of self-reported inactivity among adults—defined as less than 150 minutes of moderate-intensity physical activity per week, or less than 75 minutes of vigorous-intensity aerobic activity per week, or an equivalent combination of the two—is 23% [
In healthcare settings, very brief interventions (VBIs), defined as deliverable within 5 minutes [
We undertook to (1) estimate the effectiveness of a very brief pedometer-based intervention (‘Step it Up’) in increasing objectively measured physical activity in adults aged 40 to 74 years attending NHS Health Checks in primary care (a cardiovascular disease [CVD] risk reduction programme) compared with the Health Check alone, (2) estimate its cost-effectiveness compared with the Health Check alone from the perspectives of the NHS and society, and (3) assess the fidelity of delivery and mechanisms underlying any intervention effects.
This was a two parallel-group, randomised controlled trial (RCT) with 1:1 individual allocation. The study was registered before participant recruitment, and the protocol has been published [
We recruited patients who were eligible for the NHS Health Check, aged between 40 and 74 years, with no diagnosis of vascular disease and not on a care pathway for known risk factors (e.g., raised blood pressure) [
Participants were recruited from 23 general practices in urban and rural areas across the East of England: 12 practices in Cambridgeshire, 8 in Hertfordshire and Bedfordshire, and 3 in Norfolk. All participants gave written informed consent.
Each practice was given instructions to randomly select a subsample of 250 eligible patients out of all eligible patients on the database, and two practices randomly selected further subsamples. Individual randomisation was stratified by primary care practice. The allocation ratio was 1:1 with randomly permuted blocks of sizes 2, 4, and 6 to ensure even randomisation and low predictability of assignment within each stratum. Practice staff (nurse or healthcare assistant) randomised the participants at the start of the Health Check using a web-based tool (
Healthcare practitioners attended a 3-hour training session on study procedures and intervention delivery at their practice. To promote fidelity of delivery, practitioners were encouraged to use a brief procedure, a case report form (CRF), and the Step it Up intervention booklet during the consultation.
Participant recruitment was through the NHS Health Check programme [
At the start of the Health Check, the health practitioner obtained informed consent from participants following Good Clinical Practice guidelines [
Participants in the control group received the usual NHS Health Check only. This included blood pressure measurement, calculation of BMI from measured height and weight, and collection of a blood sample [
Baseline data were collected by practitioners. Outcomes were measured by accelerometer and questionnaires 3 months later, which were returned by participants in reply-paid envelopes [
The primary outcome was physical activity (total volume of body movement) measured by tri-axial accelerometry (Actigraph GT3X+ or Actigraph w-GT3X-BT, Actigraph, Pensacola, Florida) expressed as average vector magnitude acceleration (counts per minute [cpm]). Participants were posted an accelerometer on an elastic belt and asked to wear it around their waist on the right hip for 7 consecutive days during waking hours. Data were collected at 60 Hz and integrated into 10-second epochs; we removed non-wear time defined as ≥90 minutes of consecutive zeros (on the vertical axis) and summarised remaining vector magnitude data into average acceleration (cpm). Data were considered valid if there were at least 3 days of data, each day requiring ≥600 minutes of wear time. Secondary physical activity outcomes derived from accelerometer data were step counts (average step counts per day, derived from frequency analysis) as well as average number of minutes per day spent in moderate activity (2,690–6,166 cpm), vigorous activity (≥6,167 cpm), and moderate or vigorous activity (≥2,690 cpm) [
We assessed primary and secondary NHS care contacts and out-of-pocket expenditure on health, sports clubs, or other physical activities via a bespoke questionnaire. Work place productivity was based on an adapted version of the validated Work Productivity and Activity Impairment (WPAI) Questionnaire [
Process measures in the same questionnaire included recall of the Health Check consultation and enactment of key BCTs included in Step it Up such as goal setting and self-monitoring. To assess fidelity, we selected a random sample of 5 NHS Health Check consultations (10%, intervention and control group) from each practice for audio recording. We obtained 63 audio recordings from 13 out of 23 practices: 37 intervention and 26 control consultations. All consultations were independently doubly coded. Interrater reliability was >75% for all but one item, so we used the data of the main coder for analysis. We decided a priori that levels above 60% constituted an acceptable level of fidelity and decided during data analysis on a contamination level of 30% for control participants receiving intervention components.
We aimed to recruit a sample size of 1,140 (570 per group) to follow up 394 participants per group after 3 months, allowing for missing or incomplete accelerometer data for 30% of randomised participants. This provided 80% power to detect a 0.2-SD (‘small’) difference in mean activity between groups (40 cpm), based on the SD of 200 cpm estimated in our preliminary trial [
We conducted our analyses according to Consolidated Standards of Reporting Trials (CONSORT) guidelines (
Missing data for the primary outcome were handled within a sensitivity analysis. This examined the robustness of the main analysis result to its ‘Missing at Random’ (MAR) assumption by exploring the impact of departures from this assumption on the primary outcome results [
We examined prespecified subgroup variables in relation to the primary outcome: baseline CVD risk, sex, age (40–59, 60–74 years), ethnic group, educational qualifications, employment status, household income, marital status, home ownership, vehicle ownership, a deprivation score (calculated by scoring one point for each of the following: no qualifications, unemployed or full-time student, renting their home, no cars), and the Index of Multiple Deprivation (IMD) 2007, derived from the participant’s home postal code. For continuous potential moderators, e.g., modelled 10-year cardiovascular risk, we compared the estimated intervention effect in the highest tertile to that in the combined lower and middle tertiles of the moderator. SPSS version 23.0 (IBM Corporation, Armonk, NY) was used for data checking and analyses.
We conducted a within-trial economic evaluation from the perspectives of the NHS (comprising costs of delivering Step it Up and patient NHS contacts) and society (defined as the sum of NHS cost, personal out of pocket expenditure, and morbidity-related lost productivity), reporting incremental cost per 1,000 extra steps per day. Full details are reported in
We used descriptive analyses for mechanisms of any intervention effect and fidelity.
The trial had strong patient and public involvement from a panel of 4 members, two of whom were also Trial Steering Committee members. They commented on and contributed to the trial protocol, informed consent procedures and use of the web-based randomisation tool, the patient information sheet and consent form, procedures to increase recruitment and retention rates, and the contents and delivery of the Step it Up intervention, follow-up questionnaire, and the findings and dissemination. We have disseminated the results to our participants.
Based on data from 19 out of 23 practices, 6,200 participants were invited and 1,057 assessed for eligibility (see
ITT, Intention to Treat; NHS, National Health Service; PP, Per Protocol.
Participant baseline characteristics were similar in each group (
Values are percentages (numbers) unless otherwise stated.
Characteristics | Control ( |
Intervention ( |
---|---|---|
56.5 (9.4) | 55.7 (9.6) | |
61% (305) | 63% (316) | |
95% (476/500) | 96% (484/504) | |
81% (375/465) | 80% (383/480) | |
35% (164/468) | 39% (186/482) | |
Paid work | 61% (286) | 62% (301) |
Unemployed/homemaker | 6% (29) | 6% (28) |
Full-time student | 0% (0) | 0% (1) |
Retired | 32% (153) | 31% (148) |
Other | 1% (4) | 1% (4) |
Less than £18,000 | 26% (105) | 21% (88) |
£18,000–£30,999 | 22% (91) | 22% (94) |
£31,000–£51,999 | 28% (114) | 29% (124) |
£52,000–£100,000 | 18% (72) | 20% (85) |
Greater than £100,000 | 7% (28) | 8% (33) |
Manual | 24% (71) | 27% (84) |
Nonmanual | 68% (200) | 65% (203) |
Other | 8% (24) | 9% (27) |
None | 9% (46) | 9% (44) |
GCSE | 60% (290) | 66% (326) |
A-level | 6% (30) | 5% (26) |
Degree | 19% (91) | 15% (76) |
Other | 6% (28) | 4% (22) |
Ownership | 86% (399) | 88% (423) |
Rent | 13% (59) | 11% (51) |
Other | 1% (6) | 2% (8) |
94% (442/469) | 95% (458/483) | |
0 | 76% (341) | 81% (384) |
1 | 19% (84) | 14% (65) |
2 | 5% (23) | 4% (18) |
3 | 0.2% (1) | 1% (3) |
4 | 0.2% (1) | 1% (3) |
11.1 (5.7–18.9) | 10.9 (5.9–18.0) | |
6.45% (2.76%–11.34%) | 6.30% (2.40%–10.89%) | |
Inactive | 12.5% (63) | 13.7% (69) |
Moderately inactive | 19.3% (97) | 16.0% (81) |
Moderately active | 35.1% (176) | 35.2% (178) |
Active | 33.1% (166) | 35.0% (177) |
*Calculated by scoring one point for each of the following: no qualifications, unemployed or full-time student, renting their home, no cars.
**Derived from the postal code recorded on the consent form.
Accelerometer cpm at 3-month follow-up (
Variable | Control | Intervention | Intervention relative to control | |||
---|---|---|---|---|---|---|
Mean (95% CI) |
Mean (95% CI) |
Comparison of means |
||||
442 | 660 (641 to 679) | 417 | 668 (648 to 689) | 8.8 (−18.7 to 36.3) | 0.53 | |
442 | 8,191 (7,911 to 8,471) | 417 | 8,419 (8,110 to 8,729) | 242 (−172 to 656) | 0.25 | |
442 | 76.7 (73.5 to 80.1) | 417 | 77.3 (73.9 to 80.9) | 0.9% (−4.9% to 7.2%) | 0.76 | |
442 | 2.9 (2.6 to 3.2) | 417 | 3.2 (2.9 to 3.6) | 11.9% (−2.9% to 28.8%) | 0.12 | |
442 | 71.8 (68.9 to 74.8) | 417 | 72.0 (68.8 to 75.2) | 0.3% (−5.4% to 6.5%) | 0.91 |
*Means are geometric means for time in activity at different intensities and compared as the percentage by which the intervention group’s geometric mean is raised relative to that in the control group after adjustment for covariates.
**Comparison of means is adjusted for sex, 5-year age group, and practice.
***These are vector magnitude cpm.
Compared to those with missing primary outcome data, participants who completed follow-up with primary outcome had higher modelled 10-year CVD risk (median 6.7% [IQR 2.7%–11.5%] versus 4.9% [1.9%–8.7%],
In the first sensitivity analysis scenario assuming that participants with unobserved outcome data would take mean values from −50 cpm to +50 cpm from the adjusted observed effect, the resulting intervention effect ranged from 2.8 to 14.8, reflecting departures from the MAR assumption within the intervention group only. For departures within the control group only (scenario 2), the resulting intervention effect ranged from 0.1 to 17.5. For departures within both groups equally and in the same direction (scenario 3), the resulting effect ranged from 6.1 to 11.5. All values within these ranges represent a positive nonsignificant intervention effect and indicate that the main result is robust.
The PP analysis showed no difference in conclusion from the ITT results: data differed in only 2.7% of the participants. The adjusted intervention effect was 9.1 cpm (95% CI −18.6 to 36.7;
We found no evidence for heterogeneity of effect between subgroups, except for modelled CVD risk score. The intervention was associated with a reduction in activity among those at highest CVD risk and an increase in activity among those at lowest CVD risk (
Variable | Subgroup 1 | Subgroup 2 | Test between subgroups | ||
---|---|---|---|---|---|
Intervention–Control Mean (95% CI) | Intervention–Control Mean (95% CI) | ||||
Difference (95% CI) | Difference (95% CI) | ||||
529 | Females | 330 | Males | 0.35 | |
19.3 (−15.9 to 54.5) | −7.9 (−52.4 to 36.6) | ||||
369 | 60 to 74 years | 490 | 40 to 59 years | 0.24 | |
−10.3 (−52.6 to 32.0) | 23.2 (−13.4 to 59.8) | ||||
163 | Score > 0 | 624 | Score = 0 | 0.50 | |
34.6 (−30.4 to 99.5) | 9.7 (−23.0 to 42.3) | ||||
224 | Other | 610 | None or GCSE | 0.95 | |
11.3 (−44.2 to 66.8) | 9.1 (−23.9 to 42.0) | ||||
650 | Married/cohabiting | 159 | Single | 0.53 | |
4.6 (−27.4 to 36.7) | 28.0 (−37.5 to 93.4) | ||||
332 | No paid work | 482 | Paid work | 0.54 | |
−3.7 (−48.0 to 40.6) | 14.5 (−22.2 to 51.3) | ||||
348 | Not manual/other | 117 | Manual | 0.23 | |
10.3 (−31.6 to 52.1) | 62.1 (−11.3 to 135.5) | ||||
322 | <£31,000 | 387 | ≥£31,000 | 0.35 | |
−6.5 (−52.5 to 39.6) | 23.7 (−18.1 to 65.5) | ||||
546 | Lower and middle tertiles | 294 | Upper tertile | ||
44.0 (9.3 to 78.7) | −48.7 (−96.1 to −1.2) | 0.002 | |||
578 | Lower and middle tertiles | 281 | Upper tertile | ||
−3.0 (−36.6 to 30.5) | 36.0 (−12.4 to 84.4) | 0.19 | |||
261 | Inactive/moderately inactive | 598 | Moderately active/active | ||
13.6 (−36.0 to 63.2) | 2.1 (−30.4 to 34.7) | 0.71 |
†This was not prespecified.
For secondary outcomes, there were no significant differences between groups in accelerometer-derived step counts per day and time spent in moderate or vigorous, vigorous, and moderate-intensity activity (
PAEE, physical activity energy expenditure.
Variable | Control | Intervention | Intervention relative to control | |||
---|---|---|---|---|---|---|
Mean (95% CI) |
Mean (95% CI) |
Comparison of means |
||||
440 | 28.0 (26.0 to 30.0) | 418 | 29.5 (27.5 to 31.7) | 5.4% (−4.2% to 16.0%) | 0.28 | |
439 | 2.7 (2.5 to 2.9) | 418 | 2.9 (2.7 to 3.1) | 6.3% (−5.3% to 19.3%) | 0.30 | |
273 | 11.8 (10.6 to 13.2) | 269 | 13.3 (11.8 to 15.0) | 9.0% (−6.5% to 27.1%) | 0.27 | |
440 | 12.0 (10.7 to 13.4) | 416 | 12.0 (10.8 to 13.4) | 0.7% (−13.7% to 17.5%) | 0.93 | |
266 | 0.6 (0.5 to 0.8) | 257 | 0.6 (0.4 to 0.7) | −10.0% (−34.0% to 22.6%) | 0.50 | |
439 | 2.8 (2.6 to 2.9) | 418 | 2.8 (2.6 to 2.9) | 0.005 (−0.2 to 0.2) | 0.96 |
*Means are geometric means for skewed PAEE outcomes and compared as the percentage by which the intervention group’s geometric mean is raised relative to that in the control group after adjustment for covariates.
**Comparison of means is adjusted for sex, 5-year age group, and practice.
The intervention cost £18.04 per participant (£11.25 pedometer, £4.67 face-to-face consultation time with nurse, £2.12 materials). Other NHS costs were not statistically significantly different between groups (mean [SE] = +£21.55 [£24.21]). Total societal costs (including intervention, NHS, personal out-of-pocket and lost-productivity costs) were not significantly different either (mean [SE] = +£53.46 [£76.97]). Point estimate incremental cost per 1,000 steps per day was £96.32 from the NHS and £238.89 from the societal perspectives.
Based on practitioner records, 491 of 505 participants received the Step it Up intervention as planned (
Values are percentages (numbers).
Control | Intervention | ||
---|---|---|---|
82% (359/437) | 94% (392/415) | ||
39% (168/434) | 72% (296/410) | ||
6% (27/437) | 93% (379/406) | ||
51% (28/55) | 90% (346/385) | ||
37% (20/54) | 80% (306/383) | ||
15% (64/435) | 88% (368/417) | ||
5% (24/437) | 68% (281/415) | ||
31% (134/435) | 49% (202/415) | ||
82% (357/437) | 90% (376/416) | ||
43% (190/438) | 64% (266/417) | ||
66% (289/436) | 82% (341/415) | ||
6% (24/433) | 9% (39/418) | ||
A: 47% (8/17) | A: 44% (14/32) | ||
B: 53% (9/17) | B: 56% (18/32) |
*12% (
**Some participants reported having read and/or kept the booklet or pedometer when they reported not receiving it. This is not a data entry error; potential reasons are participant error or interpreting the question as meaning something else. For instance, participants may have received other written materials during the NHS Health Check.
The in-depth fidelity assessment revealed that contamination was minimal: intervention components were delivered in more than 30% of control group sessions for 3 components only, related to discussing physical activity recommendations [
An estimate of fidelity of intervention delivery based on an in-depth assessment of 37 of 505 (7.3%) audio-recorded consultations was 60%, meaning that—on average—9 out of 15 components were delivered. Components that were relatively poorly delivered concerned the BCTs: giving feedback on physical activity (51.4%), mentioning the effectiveness of pedometers (18.9%), and prompting goal setting (21.6%). Components to promote participant engagement were also relatively poorly delivered, e.g., asking participants whether they were aware of the physical activity recommendations (29.7%) and whether they had any questions (18.9%). There was large variability in fidelity of delivery across practices and practitioners. The average duration of the Health Check was a mean (SD) of 15 minutes and 16 seconds (6 minutes and 24 seconds). The average duration of VBI delivery was a mean (SD) of 3 minutes and 9 seconds (1 minute and 51 seconds).
During the trial, 10 participants reported adverse events, 5 in the intervention and 5 in the control group. Four of these were serious adverse events, 1 in the intervention group (stitches to a head injury after falling while cycling) and 2 in the control group (sepsis and surgery after hospital admission, and being fitted with a pacemaker after experiencing blackouts, respectively). The fourth serious adverse event was a suspected unexpected serious adverse event: an intervention participant reported having a pacemaker fitted between the health check and follow-up assessment but had not been diagnosed with a pre-existing condition.
Our trial showed no evidence for a positive effect of a 5-minute pedometer-based intervention delivered as part of NHS Health Checks in primary care on objectively measured and self-reported physical activity after 3 months, compared to the Health Check alone. Sensitivity analysis indicated that the main result is robust. Step it Up resulted in an increase of about 9 accelerometer cpm, whereas we considered an increase of 40 counts—equivalent to a small effect size—to be a minimum clinically significant effect. We found no evidence for a positive intervention effect in any prespecified subgroups, except that the intervention appeared to be more effective among participants with lower modelled CVD risk and less so in those with higher risk. The cost per patient of delivering Step it Up was £18, a small amount and known with reasonable certainty. As anticipated, we observed no statistically significant difference in other costs.
We discuss potential explanations for our findings in terms of study design, intervention, target group, and context. We demonstrated robust trial execution, so results are unlikely to be due to randomisation errors, confounding, selection bias, differential dropout, or contamination. The two groups were well matched at baseline and 3-month follow-up. Retention at follow-up was high at 85%, and any differences between those lost to follow-up and those who completed follow-up were similar enough in the two groups not to influence the main result. Any differences between groups at follow-up may have been attenuated by higher reactivity of control group participants to wearing an accelerometer as they had not previously received a pedometer. Such reactivity has been observed in previous physical activity trials [
Contamination was minimal and does not explain the findings. Suboptimal intervention delivery by practitioners, lack of participant engagement, and insufficient use of key recommended strategies in daily life are potential explanations. Setting physical activity goals is a key strategy, but at 3 months, only 49% of intervention participants—compared with 31% of control participants—reported setting physical activity goals. This may be due to the finding from the in-depth fidelity assessment that practitioners rarely prompted goal setting. Intervention duration was just over 3 minutes, 2 minutes less than planned (as estimated from the audio recordings) and shorter than the 5 minutes in our previous trial, in which fidelity of delivery of the pedometer intervention was higher at 72% [
Our target group was already relatively active, and there may have been limited capacity for a VBI to have an effect over and above the Health Check alone. At follow-up, objectively measured step counts in the control group (which provides the best estimate of the absolute physical activity distribution at baseline), though not accounting for any NHS Health Check effect, was 8,191 steps per day. This is slightly higher than observed in similar trials of pedometer-based interventions in UK primary care (7,479 in Pedometer And Consultation Evaluation [PACE-UP] [
Step it Up was delivered in a consultation focusing on vascular disease risk, which rendered physical activity benefits for disease prevention particularly salient, whereas our participants were on average 56 years and not on disease registers. Health Checks may not have been the optimal context, although participants in our previous studies mentioned that a discussion about physical activity during Health Checks was a good reminder [
The effectiveness of Step it Up may be increased by better delivery of BCTs and patient engagement in the consultation; offering repeated VBIs; referral to follow-up support delivered by digital technologies, by phone, or face to face; and by having an environment that is supportive of walking and cycling. This requires new research into their cost-effectiveness. Given current financial constraints in the NHS, practitioners could signpost apparently healthy adults of preretirement age to relatively cheap external support such as mobile phone applications or encourage them to purchase a pedometer. VBIs to promote physical activity might best be offered opportunistically to people with long-term conditions for which physical activity is an important component of disease management, as well as to older adults to halt the age-related decline in physical activity, alongside prescribing medication to reduce risk. A population-based study with repeated physical activity measures showed that middle-aged and older adults, including people with CVD and cancer, can live longer by becoming more physically active, irrespective of past activity levels and risk factors [
A key strength of our trial was its internal validity. We had a sufficiently large sample size to be able to detect a small effect. Our sample was well-balanced, and retention at 3-month follow-up was high in both arms. We used a validated objective measure of physical activity and population-based sampling from primary care registers. The intervention was novel in terms of its brevity and inclusion of evidence-based BCTs and was based on extensive development and pilot work [
While it could be argued that absence of baseline measurement is a potential limitation, we believe this not to be the case. With a large sample size and high retention, comparison of values of a precise, objective physical activity measure between intervention and control groups gives a valid estimate of effect. Our estimate is also a fairly good measure of change, assuming that physical activity was similar in the two groups at baseline due to randomisation and follow-up too short for population shifts in the outcome. The main advantage of baseline measures is the improvement in precision due to correlation and ability to analyse group changes over time, but our large sample size provided sufficient precision. On the other hand, baseline measurement in a pragmatic trial of a VBI has several disadvantages. Measurement effects may preclude an intervention effect on behaviour [
External validity or generalisability from clinical trials is limited by participant profile. Sixteen percent (1,007/6,200) of adults invited agreed to take part and were randomised. This participation rate was similar to the PACE-UP trial, which used population-based sampling in a similar age group (10%) [
The UK PACE-Lift trial evaluated a 10-week pedometer-based intervention in primary care consisting of four 30-minute, individually tailored sessions with practice nurses and found a significant effect at 3 and 12 months (1,037 and 609 additional steps per day, respectively). The UK PACE-UP trial evaluated a 12-week pedometer-based intervention delivered by mail only and by mail plus three 20-minute practice nurse consultations [
Our findings do not imply that primary care practitioners should refrain from providing (very) brief physical activity advice opportunistically as our evidence is limited to NHS Health Checks. They should be considered in the context of meta-analytic evidence supporting intensive pedometer interventions in predominantly small samples of younger participants [
This large, well-conducted trial of a plausible very brief pedometer-based intervention embedded in NHS Health Checks found no evidence of effect on objectively measured activity at 3-month follow-up. Despite the intervention being apparently simple and very brief, fidelity of delivery was suboptimal. Trial participants were more active than might have been expected. Commissioners should consider effect size, context, population, risk, and opportunity cost in commissioning individual health-service–based preventive interventions. Continual adding of preventive actions of limited benefit to clinical encounters may overburden consultations and adversely impact the efficiency and effectiveness of primary care.
(PDF)
(DOCX)
Consolidated Standards of Reporting Trials (CONSORT) checklist.
(DOCX)
(DOCX)
This study was conducted on behalf of the Very Brief Interventions Programme team (see
behaviour change technique
counts per minute
case report form
cardiovascular disease
General Certificate of Secondary Education
Index of Multiple Deprivation
Intention to Treat
Missing at Random
National Health Service
Pedometer Accelerometer Consultation Evaluation-Lift
Pedometer And Consultation Evaluation trial
physical activity energy expenditure
Per Protocol
randomised controlled trial
Recent Physical Activity Questionnaire
very brief intervention
Work Productivity and Activity Impairment
Dear Dr. Hardeman,
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Please let me know if you have any questions. Otherwise, we will look forward to receiving your revised manuscript in due course.
Sincerely,
Richard Turner, PhD
Senior Editor, PLOS Medicine
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Requests from the editors:
Our data policy calls for a primary non-author contact for inquiries about access to data, and so we ask you to remove the author contact details. Please adapt the data statement wording to "... will be made available upon reasonable request". It may be helpful to add additional institutional contact details at a future stage.
It may be that the competing interest with AbbVie can be removed in view of the date: please consult our conflict of interest policy (
Please adapt the title to "Evaluation of a very brief ...".
Please add an additional sentence or two to your abstract to summarize the secondary outcome findings.
We ask you to add a new final sentence of the "methods and findings" subsection of your abstract to summarize the study's main limitations.
Please refer to the attached CONSORT document at a suitable point in your methods section. We ask you to include the study analysis plan as a supplementary document if possible, and again refer to this in the main text. Please highlight any analyses that were not prespecified in the main text (including that noted in the supplementary file).
At the start of the discussion section of your main text, "rigorously conducted" seems a little strident, and could be de-emphasized by being moved to the "strengths and limitations" section.
There may be an indication in figure 1 and elsewhere of greater attrition in the intervention arm, and we suggest addressing this in the "strengths and limitations" section.
Please substitute "sex" for "gender" as appropriate throughout the text.
Throughout the text, please adapt reference call-outs to the following style: "... per day [11,12].".
Please review the reference list to ensure that journal names are abbreviated consistently (e.g., "PLoS Med." for reference 27).
Please adapt your attached CONSORT checklist so that individual items are referred to by section (e.g., "Methods") and paragraph number rather than by line or page numbers, as the latter generally change upon publication.
As the trial protocol is published, you may wish to remove the attached document.
Comments from the reviewers:
*** Reviewer #1 (statistical reviewer):
This is a well-conducted RCT on the effectiveness and cost-effectiveness of a very brief pedometer-based physical activity intervention (VBI) delivered in NHS Health Checks. The study design, sample size calculation, randomisation, statistical methods and analyses, and presentation (tables and figures) and interpretation of results are mostly adequate and of a good standard. However, there are still a few issues needing attention.
1) On page 17, it would be good to provide a table on comparisons between patients with complete data and those with missing data, maybe as supplementary tables.
2) Table 1. Could authors please put a percentage sign (%) for all the percentages in the table?
3) The first paragraph on page 20 provides key results for the paper including ITT analysis, sensitivity analysis and PP analysis. Could authors please highlight these analyses (maybe use subtitles) and also make it very clear whether these results are significant or not, therefore deliver a clear message on whether these analyses changed results in any way. Also, for sensitivity and PP analyses could authors please provide complete results as supplementary tables?
4) In table 2, the primary outcome analysis was only adjusted for age, gender and practice however there are quite a few other variables in the baseline which could potentially be adjusted such as Physical activity status and multiple deprivation (IMD). Would adjusting for more baseline variables change the final results in any way?
*** Reviewer #2:
This is a well-written report of an apparently well-conducted trial addressing an important question. The interpretation of the results is appropriate.
I support the choice of a pragmatic trial in a "real-world" context. The findings are of course disappointing but this manuscript nonetheless makes an important contribution.
My only concern is the statement "Fidelity of delivery was partial." in the abstract. I think this is potentially misleading given the information on page 26 that "491/505 participants received the 'Step It Up' intervention as planned." I understand that this statement is based on the assessment of program content but feel that this should be made clearer and both pieces of information should be presented in the abstract.
*** Reviewer #3:
This is an interesting topic and novel, useful and pragmatic approach, with potential for wide public health reach. It demonstrates a good example of the integration of BCTs within very short intervention.
There are a number of issues which I think need to be explained more clearly in the paper before publishing:
* Most participants were already active at baseline (GPPAQ and report of control group's step count >8000 steps), and so it is unclear why they received an intervention designed for inactive people and were not screened out. A sub-group analysis on the inactive patients may be more appropriate to demonstrate the effectiveness of the intervention.
* Author Summary statement - last point "Our general population findings do not imply that primary care practitioner should refrain from providing (very) brief PA advice opportunistically" has too many double negatives. Simply - Primary Care professionals should continue to providing very brief PA advice, opportunistically.
* Given the focus on a pragmatic intervention and approach, one of the key findings should be in relation to the poor fidelity of the intervention - it is important to note that the intervention was not delivered as intended on this occasion. This is especially pertinent given the aspects which were not delivered relate to aspects expected to support behaviour change. The results of the fidelity test should be in the results section of the abstract prior to the sentence "There were no significant between-group differences in activity volume (8.8 counts per minute; 95% CI -18.7, 36.3)" in order to alert readers that they should interpret the lack of difference between groups with care.
* Re: NHS Health Checks - would be useful to know how many people attend these across England, to better understand reach.
* Although there is a protocol paper available - Information is insufficient to understand intervention - An additional sentence here would be useful - What goals were suggested? Were they individualised? Over how many weeks? Etc
***
Any attachments provided with reviews can be seen via the following link:
[LINK]
Submitted filename:
Dear Dr. Hardeman,
Thank you very much for re-submitting your manuscript "Evaluation of a very brief pedometer-based physical activity intervention delivered in NHS Health Checks: The VBI randomised controlled trial" (PMEDICINE-D-19-02857R1) for consideration at PLOS Medicine.
I have discussed the paper with editorial colleagues and our academic editor, and I am pleased to tell you that, provided the remaining editorial and production issues are dealt with, we expect to be able to accept the paper for publication in the journal.
The remaining issues that need to be addressed are listed at the end of this email. Any accompanying reviewer attachments can be seen via the link below. Please take these into account before resubmitting your manuscript:
[LINK]
Our publications team (
***Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.***
In revising the manuscript for further consideration here, please ensure you address the specific points made by each reviewer and the editors. In your rebuttal letter you should indicate your response to the reviewers' and editors' comments and the changes you have made in the manuscript. Please submit a clean version of the paper as the main article file. A version with changes marked must also be uploaded as a marked up manuscript file.
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Please ensure that the paper adheres to the PLOS Data Availability Policy (see
Please let me know if you have any questions. Otherwise, we look forward to receiving the revised manuscript shortly.
Sincerely,
Richard Turner, PhD
Senior Editor, PLOS Medicine
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Requests from Editors:
Please remove the word "reasonable" from the data access statement (we feel that this is unnecessary in that the process for acquiring data is described).
Please adapt the title to indicate the country, e.g., "... NHS Health Checks in England ...".
To the "methods and findings" subsection of your abstract, please add brief aggregate demographic characteristics of study participants.
Please remove the sentence beginning "The statistical analysis plan was completed ..." from the abstract to save space.
Please add the relevant p value alongside the CI to the primary endpoint difference quoted in the abstract.
Regarding adverse events, please make that "... of which two were serious".
At the start of the discussion section of the main text, please adapt the wording to "... an increase of about 9 accelerometer ...".
In the same paragraph, regarding the subgroup analyses we ask you to soften the wording to "... the intervention appeared to be more effective among participants ...".
Please ensure that all entries in the reference list meet journal format. All text in italics should be converted to plain text; and where appropriate 6 rather than 3 author names should be listed, followed by "et al.". Please abbreviate journal names consistently (e.g., "PLoS Med.").
Please substitute a version of the attached CONSORT checklist in which the tracking has been cleared.
***
Submitted filename:
Dear Dr Hardeman,
On behalf of my colleagues and the academic editor, Dr. Catherine Sherrington, I am delighted to inform you that your manuscript entitled "Evaluation of a very brief pedometer-based physical activity intervention delivered in NHS Health Checks in England: The VBI randomised controlled trial" (PMEDICINE-D-19-02857R2) has been accepted for publication in PLOS Medicine.
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Thank you again for submitting the manuscript to PLOS Medicine. We look forward to publishing it.
Best wishes,
Richard Turner, PhD
Senior Editor
PLOS Medicine