Participants and data collected
All 188 acute trusts in the four countries were invited to participate. Trust chief executives, medical and nursing directors (Binleys database) were sent a letter of invitation. A total of 19 Trusts were recruited and remained in the trial. We have no reason to believe that the characteristics of participating Trusts were different from any other NHS Trusts. However, given their willingness to participate, we have to assume they have an interest and therefore motivation to want to do something about their fasting times, which may have made them atypical of other non-participating trusts. Data were collected between November 2006 and February 2009 at a time where the NHS was undergoing major reform under a previous administration (see Table for data collected). Anecdotal feedback from some sites that made further enquiries, but who then did not participate, would suggest that engaging in an additional initiative at a time of change was not feasible for them. Seven trusts were allocated to SD, six to SD plus web-based resource championed by an opinion leader, and six to SD plus PDSA. One PDSA trust did not implement the intervention due to staff sickness.
Summary of data collected across timepoints and intervention groups
Not all trusts were able to collect data for all eight timepoints. Pre-intervention (because of lengthy governance procedures), three trusts had information from timepoint four only, four trusts had information from timepoints three and four, 12 trusts had information from more than two pre-intervention timepoints. Post-intervention, one trust had information from only one timepoint, one trust had information for two post-intervention timepoints, 17 trusts had information from more than two post-intervention timepoints.
Duration of fluid and food fast pre- and post-intervention
Trends over timepoints
ANOVA showed no significant difference in mean over time for either food or fluid fast time at any Trust pre-intervention and post-intervention. Additionally within each intervention group there was no evidence of a trend across time pre-or post-intervention (Table ).
Intervention group across pre-and post-intervention timepoints
Pre-intervention fluid and food fasting times
Across all hospitals, information was gathered from 1,575 patients in total in the pre-intervention period (fluid fast time was missing for 135 patients and food fast time missing for 140 patients). There was no significant difference in the mean food fasting time across the four timepoints (ANOVA, p
0.677), the overall mean food fasting time pre-intervention was 14.0
hours (95% CI 13.6, 14.4). Also, there was no significant difference in the mean fluid fasting time across the four timepoints (ANOVA, p
0.877), the overall mean fluid fasting time pre-intervention was 9.63
hours (95% CI 8.67, 10.6). For 68.4% of patients the fluid fast exceeds six hours, and for 31.3% of patients it exceeds 12
hours in the pre-intervention period. The intracluster correlation for food fasting time pre-intervention was 0.027 and for fluid fasting was 0.12.
Post-intervention fluid and food fasting times
Across all Trusts information was gathered from 1930 patients in total in the post-intervention period (fluid fast was missing for 169 patients and food fast for 153 patients post-intervention). There was no significant difference in the mean food fasting time across the four timepoints (ANOVA, p
0.951) or in the mean fluid fasting time across the four timepoints (ANOVA, p
0.311). The mean food fast was 14.3
hours (95% CI 13.8, 14.8) and mean fluid fast 8.72
hours (95% CI 7.87, 9.57).
Comparing the three intervention groups pre-and post-intervention
In the pre-intervention period there was no significant difference in the mean food fast time between interventions (ANOVA, p
0.662). All the intervention groups appeared to be similar with regard to food fast. There was also no significant difference in the mean fluid fast time in the pre-intervention period across the intervention groups (ANOVA, p
Post-intervention there was no significant difference in the mean food fast time between intervention groups (ANOVA, p
0.641). In the post-intervention phase all the intervention groups appeared to be similar with regard to food fast. There was also no significant difference in the mean fluid fast time in the post-intervention period between the intervention groups (ANOVA, p
The mean food and fluid fasting times for each intervention group at both pre- and post-intervention are shown in Table together with the change in mean food and fluid fasting time (from pre-intervention to post-intervention) within each intervention group. The changes within each intervention group are small. For mean food fast, using a generalised linear model, neither the intervention nor the variable indicating pre/post-intervention is significant; Figure compares the pre- and post-intervention food fast data for each intervention group. Similarly for mean fluid fast, using a generalised linear model, neither the intervention nor the variable indicating pre/post-intervention is significant; Figure compares the pre- and post-intervention fluid fast data for each intervention group. Considering the change in fluid fasting time, the effect size for the web-based intervention compared to SD alone is 0.33 (95% CI −0.78, 1.42) and for PDSA compared to SD alone is 0.12 (95% CI −0.97, 1.21). These are small effect sizes; neither intervention shows the substantial impact beyond SD that would be required to reduce the mean fluid fasting time close to that recommended in the guidelines. For all three intervention groups, the post-intervention mean fluid fast time remains substantially above the guideline recommendation of two hours. Indeed, for 62.7% of patients the fluid fast exceeds six hours (the recommendation for food fast) and for 27.9% of patients it exceeds 12
Mean food and fluid fasting times in hours with 95% confidence intervals for each intervention group pre- and post-intervention and for change in mean fasting time from pre-to post-intervention
Mean and 95% CI for food fast time for each intervention group comparing pre- and post-intervention results.
Mean and 95% CI for fluid fast time for each intervention group comparing pre- and post-intervention results.
Summary pre- and post-intervention fasting times
Both fluid and food duration of fasting data shows no significant change post-intervention for any of the three interventions. The effect sizes of the more intensive interventions compared to SD alone are small. Duration of fluid fast continues to substantially exceed the two-hour recommendation and food fast remains substantially longer than six hours regardless of the intervention used. Thus no particular intervention strategy was more effective than another.
A cost analysis of the three interventions was undertaken (see Additional File 3
). Given that standard intervention was used in all three arms, the arm that received just standard intervention will by definition, have the lowest cost. One might assume this would be the most cost-effective intervention if the three approaches were shown to have equal effectiveness. Whilst the study did not detect a significant difference, it was not designed to demonstrate equivalence, and therefore it is not possible to say that SD is the most cost-effective approach. In fact, the variation in outcome within each intervention arm is likely to reflect the significant variation in activity, and therefore the resource use and cost, between the individual Trusts within each intervention arm.
Findings from the questionnaires (n
2,284, of which 1,069 were pre-intervention and 1,215 were post-intervention) and interviews (n
70) relate to provision of information, management of delay and symptoms of fasting.
Provision of information
Information about fasting was provided at least once for 89% of patients pre-intervention and for 91.6% of patients post-intervention. Information was sent by the hospital before admission for 55.8% of patients in the pre-intervention period and for 55.9% of patients post-intervention. One-fifth of patients (19.7% pre-intervention and 23.4% post-intervention) had information provided during the pre-admission clinic, but did not have information sent to them. For about a tenth of patients (10.7% pre-intervention and 10.6% post-intervention), they reported information about stopping eating and drinking only being provided on admission to the ward.
Patients liked clear consistent information, with repetitions being useful. Generally, patients were advised to fast as if they were going to be first on the list. Most patients reported ‘complying’ with instructions and in many cases were overly cautious by choosing to fast for longer than they needed to, 18.9% of patients pre-intervention and 18.1% post-intervention reported choosing to stop eating or drinking prior to their operation at different times to those recommended by the staff.
Management of delay
Interview data showed that patients were tolerant of busy ward environments and often sympathetic to the need to prioritise the list order, sometimes rationalising that delays are due to emergencies or that organising the list is challenging. Patients reported being frustrated by not being reviewed if their operation was delayed.
Symptoms of fasting
Approximately one-half of the patients completing the survey (46.5% pre-intervention and 44% post-intervention) felt hungry before their operation, however, the majority of patients (70.7% pre-intervention and 65.4% post-intervention) experienced thirst.
The impact and process of implementation
Process evaluation data show a detailed picture of implementation processes within and across the 19 trusts and that the study impacted in other ways other than on the primary outcome. These findings are described below under the main elements of the conceptual framework: evidence, context, and facilitation.
Table summarises some of the impacts of the study had in trusts described by facilitators, opinion leaders and key contacts. The study may have had an impact on aspects of practice and service delivery that did not translate into changes to length of fast. Some of the influences on attempts to changing practice are outlined below (and will be described in detail in a separate publication).
Summary of impact with examples
The research underpinning the fasting recommendations could be judged as strong, coming from robust RCTs, and ‘badged’ by relevant UK Royal Colleges and Societies. Interview data suggests that most nursing and anaesthetists interviewed thought the evidence underpinning the recommendations was good and the guideline credible, for example:
"‘…I am quite happy about the evidence base … this guideline is not negotiable… you can’t say ‘well I don’t like this bit of it’…it’s based on best evidence.’ (Trust G, Key Contact and Change Agent [nurse])"
Issues were raised about the interpretation of some of the recommendations, such as what clear fluids meant, and the amount of water patients could drink.
Anaesthetists’ reaction to the evidence base tended towards conservative behaviour, which seemed to be based on prior experience where lists had worked well using traditional fasting rules, for example:
"‘… Why the extra aggro if there’s a sudden change in the list…I’ve been doing it x years and I’ve never had a cancellation because of that.. I personally… modify the rules. If somebody turns up having had a jug of water and it’s only one hour and 45
minutes I’ll go ahead and anaesthetise them. Other guys will say…let’s cancel, postpone.’ (Trust L, Anaesthetist Key Contact and Change Agent)"
Contextual factors were important influences on individual’s and trust’s capability to change practises in line with guideline recommendations, not least that it is challenging to change service delivery in a constantly changing environment. Three main findings are outlined here.
Inter-professional relationships were a significant emergent theme across all data. This incorporated different professional approaches, leadership, power and hierarchical structures, and professional cultures. Although we did not set out to specifically explore professional culture data, findings show that fasting practice was influenced by how the disciplines functioned together, sometimes bringing them into conflict because they had different objectives, ways of working and power bases.
"‘… The fasting guidelines are… embedded in so many different cultures that – so many different aspects of the organisation that they really are quite difficult to change.’ (Trust R Anaesthetist PDSA Facilitator)"
There was a professional struggle over fasting practice within Trusts. For example, one anaesthetist key contact (Trust J) sent out emails to medical staff promoting shorter fast times. Some of their colleagues replied ‘this is my theatre.’ Often, such behaviour resulted in nurses being caught in the middle of variances in practice between anaesthetists.
Linked to inter-professional working, the nature and quality of communication between individuals, teams, and departments significantly impacted on fasting practice. In some trusts, communication between theatres and wards about delays was considered good. In others it was poor and seen as an area for improvement particularly with respect to revising and individualising fasting times.
"‘…We’ve had a phone call from theatre to say this patient’s been cancelled and you can feed and water them. Half an hour later we’ve had a phone call saying has she or he been fed and watered, she can go down so there’s been a big miscommunication or been told completely wrong....’ (Trust A Nurse, Focus group-SD)"
The response rates to the Learning Organization Survey were low (18% pre-intervention and 7.4% post-intervention) and therefore findings interpreted with caution. General features to emerge included that the organisations in this study were perceived to be highly structured, rule-based organisations. Over 50% of responders did not feel innovative ideas were rewarded, and fewer than 60% of the responders believed they are required to upgrade and increase their knowledge. Less than 50% of responders did not feel an integral part of their Trust.
Opinion leaders and PDSA facilitators within two intervention arms had the potential to take on facilitation roles (‘making things easier’). In reality, the enactment of these roles varied and linked to activities rather than the model of facilitation/change agency of the intervention. As such, fidelity to interventions was variable and as a research team did not intervene in the intervention phase. Skills and attributes and activities are summarised in Tables and .
Skills and attributes of opinion leaders and facilitators
Whilst the research evidence underpinning fasting recommendations was strong and relatively uncontested, its translation into practice was challenging. Overall, there was no significant change to fluid and food fasting times pre- and post-intervention and no significant differences between the effectiveness of the three implementations. There were some significant decreases in fluid fast times within trusts, but in two trusts there was a significant increase in either fluid or fast times. These data present a complex, but realistic picture of implementation within acute care settings where multiple people, teams, and departments are involved.