Ian Kellar
Research interests
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InterestsRisk Communication, Behavioral Medicine, Health Behavior, Medication Adherence, prospective memory, health behaviour change, Implementation Intentions
Publications
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1.71Impact points
An explanatory randomised controlled trial of a nurse-led, consultation-based intervention to support patients with adherence to taking glucose lowering medication for type 2 diabetes.
BMC family practice. 04/2012; 13(1):30.
ABSTRACT: BACKGROUND: Failure to take medication reduces the effectiveness of treatment leading to increased morbidity and mortality. We evaluated the efficacy of a consultation-based intervention to support objectively-assessed adherence to oral glucose lowering medication (OGLM) compared to usual ... [more] ABSTRACT: BACKGROUND: Failure to take medication reduces the effectiveness of treatment leading to increased morbidity and mortality. We evaluated the efficacy of a consultation-based intervention to support objectively-assessed adherence to oral glucose lowering medication (OGLM) compared to usual care among people with type 2 diabetes. METHODS: This was a parallel group randomised trial in adult patients with type 2 diabetes and HbA1c[greater than or equal to]7.5% (58 mmol/mol), prescribed at least one OGLM. Participants were allocated to a clinic nurse delivered, innovative consultation-based intervention to strengthen patient motivation to take OGLM regularly and support medicine taking through action-plans, or to usual care. The primary outcome was the percentage of days on which the prescribed dose of medication was taken, measured objectively over 12 weeks with an electronic medicationmonitoring device (TrackCap, Aardex, Switzerland). The primary analysis was intention-totreat. RESULTS: 211 patients were randomised between July 1, 2006 and November 30, 2008 in 13 British general practices (primary care clinics). Primary outcome data were available for 194 participants (91.9%). Mean (sd) percentage of adherent days was 77.4% (26.3) in the intervention group and 69.0% (30.8) in standard care (mean difference between groups 8.4%, 95% confidence interval 0.2% to 16.7%, p = 0.044). There was no significant adverse impact on functional status or treatment satisfaction. CONCLUSIONS: This well-specified, theory based intervention delivered in a single session of 30 min in primary care increased objectively measured medication adherence, with no adverse effect on treatment satisfaction. These findings justify a definitive trial of this approach to improving medication adherence over a longer period of time, with clinical and cost-effectiveness outcomes to inform clinical practice. Trial registration Current Controlled Trials ISRCTN30522359.
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Impact of informed-choice invitations on diabetes screening knowledge, attitude and intentions: an analogue study
BMC Public Health. 01/2010;
Abstract Background Despite concerns that facilitating informed choice would decrease diabetes screening uptake, 'informed choice' invitations that increased knowledge did not affect attendance (the DICISION trial). We explored possible reasons using data from an experimental analo... [more] Abstract Background Despite concerns that facilitating informed choice would decrease diabetes screening uptake, 'informed choice' invitations that increased knowledge did not affect attendance (the DICISION trial). We explored possible reasons using data from an experimental analogue study undertaken to develop the invitations. We tested a model of the impact on knowledge, attitude and intentions of a diabetes screening invitation designed to facilitate informed choices. Methods 417 men and women aged 40-69 recruited from town centres in the UK were randomised to receive either an invitation for diabetes screening designed to facilitate informed choice or a standard type of invitation. Knowledge of the invitation, attitude towards diabetes screening, and intention to attend for diabetes screening were assessed two weeks later. Results Attitude was a strong predictor of screening intentions (β = .64, p = .001). Knowledge added to the model but was a weak predictor of intentions (β = .13, p = .005). However, invitation type did not predict attitudes towards screening but did predict knowledge (β = -.45, p = .001), which mediated a small effect of invitation type on intention (indirect β = -.06, p = .017). Conclusions These findings may explain why information about the benefits and harms of screening did not reduce diabetes screening attendance in the DICISION trial.
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2.22Impact points
Impact of informed-choice invitations on diabetes screening knowledge, attitude and intentions: an analogue study.
BMC public health. 01/2010; 10:768.
Despite concerns that facilitating informed choice would decrease diabetes screening uptake, 'informed choice' invitations that increased knowledge did not affect attendance (the DICISION trial). We explored possible reasons using data from an experimental analogue study undertaken to develo... [more] Despite concerns that facilitating informed choice would decrease diabetes screening uptake, 'informed choice' invitations that increased knowledge did not affect attendance (the DICISION trial). We explored possible reasons using data from an experimental analogue study undertaken to develop the invitations. We tested a model of the impact on knowledge, attitude and intentions of a diabetes screening invitation designed to facilitate informed choices. 417 men and women aged 40-69 recruited from town centres in the UK were randomised to receive either an invitation for diabetes screening designed to facilitate informed choice or a standard type of invitation. Knowledge of the invitation, attitude towards diabetes screening, and intention to attend for diabetes screening were assessed two weeks later. Attitude was a strong predictor of screening intentions (β = .64, p = .001). Knowledge added to the model but was a weak predictor of intentions (β = .13, p = .005). However, invitation type did not predict attitudes towards screening but did predict knowledge (β = -.45, p = .001), which mediated a small effect of invitation type on intention (indirect β = -.06, p = .017). These findings may explain why information about the benefits and harms of screening did not reduce diabetes screening attendance in the DICISION trial.
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Impact of an informed choice invitation on uptake of screening for diabetes in primary care (DICISION): randomised trial.
BMJ (Clinical research ed.). 01/2010; 340:c2138.
To compare the effect of an invitation promoting informed choice for screening with a standard invitation on attendance and motivation to engage in preventive action. Randomised controlled trial. Four English general practices. 1272 people aged 40-69 years, at risk for diabetes, identified from prac... [more] To compare the effect of an invitation promoting informed choice for screening with a standard invitation on attendance and motivation to engage in preventive action. Randomised controlled trial. Four English general practices. 1272 people aged 40-69 years, at risk for diabetes, identified from practice registers using a validated risk score and invited to attend for screening. Intervention was a previously validated invitation to inform the decision to attend screening, presenting diabetes as a serious potential problem, and providing details of possible costs and benefits of screening and treatment in text and pie charts. This was compared with a brief, standard invitation simply describing diabetes as a serious potential problem. The primary end point was attendance for screening. The secondary outcome measures were intention to make changes to lifestyle and satisfaction with decisions made among attenders. The primary end point was analysed for all 1272 participants. 55.8% (353/633) of those in the informed choice group attended for screening, compared with 57.6% (368/639) in the standard invitation group (mean difference -1.8%, 95% confidence interval -7.3% to 3.6%; P=0.51). Attendance was lower among the more deprived group (most deprived third 47.5% v least deprived third 64.3%; P<0.001). Interaction between deprivation and effect of invitation type on attendance was not significant. Among attenders, intention to change behaviour was strong and unaffected by invitation type. Providing information to support choice did not adversely affect attendance for screening for diabetes. Those from more socially deprived groups were, however, less likely to attend, regardless of the type of invitation received. Further attention to invitation content alone is unlikely to achieve equity in uptake of preventive services. Current Controlled Trials ISRCTN 73125647.
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2.22Impact points
Impact of an informed choice invitation on uptake of screening for diabetes in primary care (DICISION): trial protocol.
BMC public health. 03/2009; 9(1):63.
ABSTRACT: BACKGROUND: Screening invitations have traditionally been brief, providing information only about population benefits. Presenting information about the limited individual benefits and potential harms of screening to inform choice may reduce attendance, particularly in the more socially dep... [more] ABSTRACT: BACKGROUND: Screening invitations have traditionally been brief, providing information only about population benefits. Presenting information about the limited individual benefits and potential harms of screening to inform choice may reduce attendance, particularly in the more socially deprived. At the same time, amongst those who attend, it might increase motivation to change behavior to reduce risks. This trial assesses the impact on attendance and motivation to change behavior of an invitation that facilitates informed choices about participating in diabetes screening in general practice. Three hypotheses are tested: 1. Attendance at screening for diabetes is lower following an informed choice compared with a standard invitation. 2. There is an interaction between the type of invitation and social deprivation: attendance following an informed choice compared with a standard invitation is lower in those who are more rather than less socially deprived. 3. Amongst those who attend for screening, intentions to change behavior to reduce risks of complications in those subsequently diagnosed with diabetes are stronger following an informed choice invitation compared with a standard invitation. METHODS: 1500 people aged 40-69 years without known diabetes but at high risk are identified from four general practice registers in the east of England. 1200 participants are randomized by households to receive one of two invitations to attend for diabetes screening at their general practices. The intervention invitation is designed to facilitate informed choices, and comprises detailed information and a decision aid. A comparison invitation is based on those currently in use. Screening involves a finger-prick blood glucose test. The primary outcome is attendance for diabetes screening. The secondary outcome is intention to change health related behaviors in those attenders diagnosed with diabetes. A sample size of 1200 ensures 90% power to detect a 10% difference in attendance between arms, and in an estimated 780 attenders, 80% power to detect a 0.2 sd difference in intention between arms. DISCUSSION: The DICISION trial is a rigorous pragmatic denominator based clinical trial of an informed choice invitation to diabetes screening, which addresses some key limitations of previous trials.
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Impact of an informed choice invitation on uptake of screening for diabetes in primary care (DICISION): trial protocol
BMC Public Health. 01/2009;
Abstract Background Screening invitations have traditionally been brief, providing information only about population benefits. Presenting information about the limited individual benefits and potential harms of screening to inform choice may reduce attendance, particularly in the more socially dep... [more] Abstract Background Screening invitations have traditionally been brief, providing information only about population benefits. Presenting information about the limited individual benefits and potential harms of screening to inform choice may reduce attendance, particularly in the more socially deprived. At the same time, amongst those who attend, it might increase motivation to change behavior to reduce risks. This trial assesses the impact on attendance and motivation to change behavior of an invitation that facilitates informed choices about participating in diabetes screening in general practice. Three hypotheses are tested: 1. Attendance at screening for diabetes is lower following an informed choice compared with a standard invitation. 2. There is an interaction between the type of invitation and social deprivation: attendance following an informed choice compared with a standard invitation is lower in those who are more rather than less socially deprived. 3. Amongst those who attend for screening, intentions to change behavior to reduce risks of complications in those subsequently diagnosed with diabetes are stronger following an informed choice invitation compared with a standard invitation. Method/Design 1500 people aged 40–69 years without known diabetes but at high risk are identified from four general practice registers in the east of England. 1200 participants are randomized by households to receive one of two invitations to attend for diabetes screening at their general practices. The intervention invitation is designed to facilitate informed choices, and comprises detailed information and a decision aid. A comparison invitation is based on those currently in use. Screening involves a finger-prick blood glucose test. The primary outcome is attendance for diabetes screening. The secondary outcome is intention to change health related behaviors in those attenders diagnosed with diabetes. A sample size of 1200 ensures 90% power to detect a 10% difference in attendance between arms, and in an estimated 780 attenders, 80% power to detect a 0.2 sd difference in intention between arms. Discussion The DICISION trial is a rigorous pragmatic denominator based clinical trial of an informed choice invitation to diabetes screening, which addresses some key limitations of previous trials. Trial registration Current Controlled Trials ISRCTN73125647
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1.98Impact points
Evaluation of an informed choice invitation for type 2 diabetes screening.
Patient education and counseling. 09/2008; 72(2):232-8.
OBJECTIVE: To evaluate an innovative invitation designed to facilitate informed choices for undergoing screening for type 2 diabetes. METHODS: Four hundred and seventeen people aged 40-69 years (sex: F 53%/M 47%), without known diabetes, recruited from street locations. Participants were randomised ... [more] OBJECTIVE: To evaluate an innovative invitation designed to facilitate informed choices for undergoing screening for type 2 diabetes. METHODS: Four hundred and seventeen people aged 40-69 years (sex: F 53%/M 47%), without known diabetes, recruited from street locations. Participants were randomised to receive one of two hypothetical invitations for screening for type 2 diabetes; one based on General Medical Council guidelines and combined with a decisional balance sheet, the other a brief traditional invitation. Informed choice was assessed immediately after the invitation and 3 weeks later using measures of knowledge, attitudes and intentions. RESULTS: Two weeks after receipt of the invitation, the proportion of informed choices was significantly higher among participants who received the informed choice invitation compared with those who received the traditional invitation (42.9% versus 11.2%; difference=31.7%, 95% CI: 22.5-40.5%; p<0.001). Mean knowledge scores were significantly higher after the receipt of the invitation designed to facilitate informed choices than after the traditional invitation (5.49 versus 3.90; t(405)=10.106, p<0.001). Intentions to participate in screening were unaffected by receipt of the informed choice invitation. CONCLUSION: Compared with a traditional invitation, receipt of the invitation designed to facilitate informed choices increased the proportion of informed choices about type 2 diabetes screening attendance. PRACTICE IMPLICATIONS: : Although the new invitation was associated with better knowledge of screening it had no differential effect on intention and its effect on attendance still requires evaluation.
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1.49Impact points
Randomized controlled trial of a brief research-based intervention promoting fruit and vegetable consumption.
British journal of health psychology. 12/2005; 10(Pt 4):543-58.
OBJECTIVE: The present study sought to test the efficacy of a brief research-based, leaflet-like intervention to promote eating the recommended daily intake of fruit and vegetables (RDIFV). DESIGN: A controlled, pre- post-test experimental study with random allocation and a 1 week self-report behavi... [more] OBJECTIVE: The present study sought to test the efficacy of a brief research-based, leaflet-like intervention to promote eating the recommended daily intake of fruit and vegetables (RDIFV). DESIGN: A controlled, pre- post-test experimental study with random allocation and a 1 week self-report behavioural follow-up was conducted. METHOD: The intervention employed persuasive communication targeting self-efficacy and intention, and invited participants to form implementation intentions in relation to acquiring and preparing fruit and vegetables for consumption. RESULTS: Intervention participants had stronger post-intervention intentions to consume the RDIFV, and higher anticipated regret in relation to failing to do so, compared with controls, controlling for pre-intervention scores. At follow-up, the intervention group was found to have eaten more fruit and vegetables and to have consumed the RDIFV more frequently. DISCUSSION: It is concluded that this study supports the previously reported power of implementation intentions to prompt enactment of intentions, and that a brief research-based leaflet-like intervention could result in immediate enhancement of intentions and anticipated regret, and promote greater fruit and vegetable consumption.
Following (6)
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Steven Paul Woods
University of California at San Diego -
Tracy Epton
The University of Sheffield -
James Jamison
University of Cambridge -
Paschal Sheeran
The University of Sheffield -
Matthias Kliegel
Technische Universität Dresden