treated type 2 diabetes receiving one of three diabetes control and complications trial standard, consent, beliefs about diabetes were elicited using a …
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Impact of self monitoring of blood glucose in the management of patients with non-insulin treated diabetes: open parallel group randomised trial
Andrew Farmer, Alisha Wade, Elizabeth Goyder, Patricia Yudkin, David French, Anthea Craven, Rury Holman, Ann-Louise Kinmonth and Andrew Neil BMJ 2007;335;132; originally published online 25 Jun 2007; doi:101136/bmj39247447431BE
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RESEARCH
Impact of self monitoring of blood glucose in the management of patients with non-insulin treated diabetes: open parallel group randomised trial
Andrew Farmer, lecturer,1 Alisha Wade, resident,2 Elizabeth Goyder, reader,3 Patricia Yudkin, reader,1 David French, reader,4 Anthea Craven, trial manager,1 Rury Holman, professor,5 Ann-Louise Kinmonth, professor,6 Andrew Neil, professor,7 on behalf of the Diabetes Glycaemic Education and Monitoring Trial Group
1 Department of Primary Health Care, University of Oxford, Oxford OX2 7LF 2 Johns Hopkins University School of Medicine, Baltimore 3 School of Health and Related Research, University of Sheffield 4 Applied Research Centre in Health and Lifestyle Interventions, University of Coventry 5
Diabetes Trials Unit, University of Oxford
6
Institute of Public Health,
University of Cambridge
7
Division of Public Health and Primary Care, University of Oxford Correspondence to: A Farmer andrewfarmer@dphpcoxacuk
doi:101136/bmj39247447431BE
ABSTRACT Objective To determine whether self monitoring, alone or with instruction in incorporating the results into self care, is more effective than usual care in improving glycaemic control in non-insulin treated patients with type 2 diabetes Design Three arm, open, parallel group randomised trial Setting 48 general practices in Oxfordshire and South Yorkshire Participants 453 patients with non-insulin treated type 2 diabetes mean age 657 years for a median duration of three years and a mean haemoglobin A1c level of 75 Interventions Standardised usual care with measurements of HbA1c every three months as the control group n152, blood glucose self monitoring with advice for patients to contact their doctor for interpretation of results, in addition to usual care n150, and blood glucose self monitoring with additional training of patients in interpretation and application of the results to enhance motivation and maintain adherence to a healthy lifestyle n151 Main outcome measure HbA1c level measured at 12
months Results At 12 months the differences in HbA1c level between the three groups adjusted for baseline HbA1c level were not statistically significant P012 The difference in unadjusted mean change in HbA1c level from baseline to 12 months between the control and less intensive self monitoring groups was -014 95 confidence interval -035 to 007 and between the control and more intensive self monitoring groups was -017 -037 to 003 Conclusions Evidence is not convincing of an effect of self monitoring blood glucose, with or without instruction in incorporating findings into self care, in improving glycaemic control compared with usual care in reasonably well controlled non-insulin treated patients with type 2 diabetes Trial registration Current Controlled Trials ISRCTN47464659 INTRODUCTION As the number of people diagnosed as having type 2 diabetes continues to rise1 so does the challenge of
monitoring and managing the condition Self monitoring of blood glucose for people with non-insulin treated diabetes may lead to improved glycaemic control and is commonly recommended Existing evidence of effectiveness is, however, inconclusive2-4 Despite limitations in trial evidence, proponents
of self monitoring of blood glucose cite the benefits reported in some observational studies of patients with diabetes,5 6 but these analyses may not have fully adjusted for the potential confounding effect of an association between self monitoring of blood glucose and take-up of other health improving behaviours Meanwhile the use of self monitoring in this group of patients and the cost to health systems of the consumable test strips have become a major and increasing proportion of healthcare budgets7 8 We tested whether self monitoring of blood glucose, with or without instruction in incorporating findings into self care, compared with standardised usual care can improve glycaemic control in patients with noninsulin treated diabetes
METHODS The diabetes glycaemic education and monitoring DiGEM study was a four year open, randomised, three arm, parallel group trial with sequential recruitment of patients from general practices in Oxfordshire and South Yorkshire The trial was managed from the coordinating centre at the Department of Primary Health Care, University of Oxford9 Our primary aim was to determine whether haemoglobin A1c HbA1c levels at 12 months were significantly
different between patients with non-insulin treated type 2 diabetes receiving one of three allocated interventions: standardised usual care with measurements of HbA1c levels by health professionals every three months control group; use of a blood glucose meter, with advice for participants to contact their doctor for interpretation of results less intensive self monitoring; and use of a blood glucose meter with training in self interpretation and application of the results to diet, physical activity, and drug adherence more intensive self monitoring
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Total list n364 527 No diabetes n354 646 People with diabetes n9881 Type 1 diabetes n1424 Type 2 diabetes n8457 Ineligible Meter use n1616, 30 Other n3855, 70 Total eligible n2986 No response n2031 Positive response n955, 32 Ineligible Meter use n211, 56 Other n166, 44 Eligible for assessment n578 Ineligible Meter use n2, 2 Haemoglobin A1c 62 n93, 74 Other n30, 24 Randomised n453
standardisation programme and comparable to the diabetes control and complications trial standard, with an interassay coefficient of variation across the range of
the assay of less than 2 Cholesterol was assayed in local laboratories and the results aligned with results of a sample of paired specimens analysed with an automated chemistry analyser Olympus AU400; Olympus, Tokyo, with interassay coefficients of variation across the range of less than 2 Blood pressure was measured twice in the right arm, with the participant seated, using a UA-779 electronic blood pressure monitor AD instruments, Abingdon, and the mean of these values was analysed We transcribed the frequency of blood glucose testing from patient held diaries Episodes of hypoglycaemia were categorised as grade 2 mild symptoms requiring minor intervention, grade 3 moderate symptoms requiring immediate third party intervention, or grade 4 unconscious Increases in hypoglycaemic drugs were defined as an increase in the dose or frequency prescribed, progression from use of a single oral agent to combination oral therapy, or addition of insulin to the treatment regimen To characterise the groups and identify subgroups for predefined analysis at 12 months we collected additional personal and clinical data on duration of diabetes, drug treatment, diabetes related complications, and
EuroQol EQ-5D score10
Randomisation We used computerised randomisation Minim, www sghmsacuk/depts/phs/guide/randserhtm incorporating a partial minimisation procedure to adjust the randomisation probabilities between groups to balance three important covariates collected at baseline: duration of diabetes, HbA1c level, and current treatment diet, oral monotherapy, or oral combination therapy The minimisation procedure to assign patients to their allocated intervention was conducted independently of the research nurses who managed recruitment and carried out the assessment visit The allocation was also concealed from laboratory staff Procedures We identified patients suitable for trial inclusion from lists held on computer by their general practitioners Those eligible were sent an invitation to participate signed by their general practitioner accompanied by an information sheet and a reply paid envelope One further letter was sent if no response was received within one month Eligibility for the trial and willingness to be randomised to self testing of blood glucose was confirmed by a preassessment phone call and at the visit for assessment At the assessment visit, after obtaining
informed consent, beliefs about diabetes were elicited using a standard approach to help patients understand how diabetes might present a threat to their health11 The roles of diet, physical activity, and drugs were discussed within the framework of the commonsense model of illness representation,11 in which we set out to optimise the use of feedback on glucose levels to
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Control n152 Died n1 Lost to follow-up n17 Started to monitor n8 Included in intention to treat analysis n152
Less intensive self monitoring n150 Died n3 Lost to follow-up n11 Did not persist monitoring n51 Included in intention to treat analysis n150
More intensive self monitoring n151 Died n4 Lost to follow-up n21 Did not persist monitoring n72 Included in intention to treat analysis n151
Fig 1 | Trial profile
Patients were eligible for randomisation if they had type 2 diabetes, were aged 25 years or more at diagnosis, were managed with diet or oral hypoglycaemic agents alone, had an HbA1c level 62 at the assessment visit, and were independent in activities of daily living Exclusion criteria were the use of a blood glucose monitor twice a week or more often over the previous three
months, serious disease or limited life expectancy that would make intensive glycaemic control inappropriate, or inability to follow trial procedures
Outcome measures The primary outcome was the HbA1c level at 12 months Secondary outcomes were blood pressure, weight, total cholesterol level, ratio of total cholesterol to high density lipoprotein cholesterol, and body mass index HbA1c was measured using a Variant II Hemoglobin Testing System Bio-Rad Laboratories, Hercules, CA certified by the US glycohaemoglobin
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facilitate behaviour change through influencing beliefs The behaviour change techniques were selected on the basis of evidence for effectiveness and included goal setting and review of physical activity and eating patterns to help patients with lifestyle change12 13 The goal setting and review approach was continued in subsequent visits Baseline blood tests and clinical measurements were taken and questionnaires completed at the assessment visit
Interventions After the assessment visit and confirmation of eligibility, patients were allocated to receive one of the three interventions The rationale behind these
interventions is described in more detail elsewhere9 The
Table 1 | Personal and baseline characteristics of patients with non-insulin treated type 2 diabetes before intervention, by randomisation group Values are numbers percentages unless stated otherwise
Control group n152 663 102 85 559 80 526 69 454 3 20 Meter group; less intensive self monitoring n150 652 106 88 587 81 540 68 453 1 07 Meter group; more intensive self monitoring n151 655 99 87 576 84 556 66 437 1 07
Variables Personal characteristics Mean SD age years Men Occupational group: Professional, managerial, and clerical Skilled manual or manual No occupation stated Age years at leaving full time education: 17 17 or 18 18 Cigarette consumption: Never smoked Former smoker Current smoker Duration of diabetes and treatment Median interquartile range duration years of diabetes Treatment: Diet only Monotherapy Combined oral therapy Presence of diabetes related complications Use of blood glucose meter: Not using Using once weekly or less Physical and laboratory findings Mean SD haemoglobin A1c Mean SD total cholesterol level mmol/l Mean SD blood pressure mm Hg: Systolic Diastolic Mean SD body mass index
No use of blood
glucose meter
109 717 20 132 23 151 58 382 80 526 14 92 32-6
114 760 14 93 22 147 54 362 74 497 21 141 32-7
121 801 13 86 17 113 54 358 77 510 20 132 32-6
44 289 57 375 51 336 32 211
39 260 58 387 53 353 32 213
41 272 58 384 52 344 39 258
104 684 48 316 749 109 47 11
110 733 40 267 741 102 46 11
102 675 49 325 753 112 47 11
140 18 80 10 309 61
141 17 80 10 319 62
137 18 78 10 310 53
intervention was initiated at the first visit after randomisation and continued at the scheduled visits at one, three, six, and nine months Each of the three interventions included a series of standardised components Patients allocated to the control intervention received standardised usual care, including the use of goal setting and review They were asked not to use a blood glucose meter unless their doctor considered it essential for their clinical management A diary was used to record self care goals and strategies for achieving them Patients allocated to the less intensive self monitoring intervention continued to use the goal setting and review techniques introduced at the assessment visit In addition they were given a blood glucose meter They were asked to record three values daily on
two days during the week one after fasting and the other two before meals or two hours after meals and to aim for glucose levels of 4-6 mmol/l after fasting and before meals and levels of 6-8 mmol/l two hours after meals They were advised by the nurse to consider contacting their doctor if readings were consistently high 15 mmol/l or low 4 mmol/l They were not given information about how to interpret their blood glucose readings Separate diaries were used to record identified goals and activity and to record blood glucose results Patients allocated to the more intensive intervention continued to use goal setting and review and were also given a blood glucose meter They were also given training and support in timing, interpreting, and using the results of their blood glucose test to enhance motivation and to maintain adherence to diet, physical activity, and drug regimens They were encouraged to experiment with monitoring to explore the effect of specific activities, such as exercise, on their blood glucose level and to reflect on abnormal values in an attempt to identify what might have contributed to them A single diary was used to record goals, activities, and blood glucose
results Follow-up visits differed in content according to the allocated intervention in line with usual practice Patients allocated to the control intervention had a blood test to measure HbA1c level two weeks before their scheduled visit, the result of which was fed back to them as an indication of the impact of their self care activities on their glycaemic control Blood glucose values were reviewed at the scheduled visit for those allocated to self monitoring, and patients were told to seek advice from their doctor if fasting values were persistently greater than 6 mmol/l Patients in each arm of the trial received feedback on glycaemic control, which was used to explore success of goals and to set new ones The patients doctor was notified of all HbA1c results and asked to consider changes in drugs in line with the National Institute for Clinical Excellence diabetes guidelines for all patients14 The doctor was also notified if blood glucose readings were consistently greater than 15 mmol/l The meters were calibrated to provide plasma equivalent results Optium, Abbott Diabetes Care, Maidenhead, UK Calibration of the meters was
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Haemoglobin A1c level
80 78 76 74 72
Control: no blood glucose meter Less intensive self monitoring with blood glucose meter More intensive self monitoring with blood glucose meter
checked by the research nurses using a test aliquot at baseline and at six months Data on adverse reactions or complications were collected at each study visit, together with information on the use of drugs
Delivery of intervention Training and support for the research nurses delivering the intervention was designed to ensure adherence to the study protocol15 The nurses were taught psychological theory and trained in behaviour change techniques and skills in delivering the intervention six days of case based training over five weeks Intervention protocols included scripts of the topics to be covered to guide the nurses in talking to patients Additional measures to ensure adherence to the intervention protocols included self review of taped consultations by the research nurses and external review by a sociologist Prompts were also built into the patient diaries to help patients adhere to their allocated intervention Statistical analysis The
trial was designed to have a 90 power to detect a difference of 05 in HbA1c levels as the primary end point at a two sided significance level of P005 We estimated the standard deviation of HbA1c levels to be 15 based on a previous trial of patients with type 2 diabetes,16 and assumed a 10 loss to follow-up We required a total of 630 patients to achieve the specified statistical power Subsequently we revised the estimated standard deviation for HbA1c levels to 125 when it became clear that it had been overestimated We retained a 10 dropout rate and 90 power and revised the recruitment target to 450 patients We carried out a single intention to treat analysis of the main trial end points at the end of the study using analysis of covariance to compare mean levels of HbA1c at follow-up between the three allocated groups, with the baseline level of HbA1c as a covariate If no follow-up data were available we imputed values by carrying forward the last available measurement We specified that in the event of a statistically significant overall result, comparisons of the two self monitoring groups independently with the control group would be carried out using t tests Levels of HbA1c over
the course of the trial were compared between groups using repeated measures analysis of variance We also estimated the intervention effect in prespecified subgroups defined at baseline as duration of diabetes above or below median, current management oral hypoglycaemic drugs or dietary management only, health status above or below the median EQ5D score, and presence or absence of diabetes related complications We tested for effect modification using analysis of covariance A Kaplan-Meier plot was used to explore adherence to a minimal level of self monitoring, defined as at least 26 tests over three months equivalent to two tests each week; significance was assessed with a log rank test The mean numbers of tests by patients carrying out at least 26 tests in each quarter are also reported, with differences between the less intensive and more
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P038 70 0 3 6 9 12 Time months
Fig 2 | Change in HbA1c levels over 12 months follow-up of patients with non-insulin treated type 2 diabetes according to randomisation group
Table 2 | Changes in haemoglobin A1c levels, weight, and body mass index between baseline and one year in patients with non-insulin treated
type 2 diabetes, by randomisation group Values are means standard deviations unless stated otherwise
Meter group, less intensive self monitoring n150 741 102 728 088 -014 082 Meter group, more intensive self monitoring n151 753 112 736 105 -017 073 P value for difference between groups 012
Variable HbA1c : Baseline Follow-up Change Systolic blood pressure mm Hg: Baseline Follow-up Change Diastolic blood pressure mm Hg: Baseline Follow-up Change Weight kg: Baseline Follow-up Change Total cholesterol level mmol/l: Baseline Follow-up Change Ratio of total cholesterol to high density lipoprotein cholesterol: Baseline Follow-up Change Body mass index: Baseline Follow-up Change
Control group n152 749 109 749 120 -000 102
140 18 136 18 -4 14
141 17 137 17 -3 16
137 18 134 17 -3 14
077
80 10 77 10 -3 9 867 189 864 194 -03 27
80 10 78 10 -2 9 904 189 899 190 -05 26
78 10 76 10 -2 8 869 164 861 157 -08 33
067
037
473 102 456 103 -016 084
464 111 442 095 -022 093
467 107 428 084 -040 090
0010
433 112 418 112 -015 072 309 61 308 63 -01 10
440 133 411 117 -029 086 319 62 318 63 -02 09
448 135 402 117 -046 091 310 53 307 50 -03 12
0013
041
Change is measured as one
year follow-up minus baseline values No use of blood glucose meter Adjustment for baseline values Based on 414 participants with paired values 137/152, 136/150, 141/151
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Table 3 | Changes in haemoglobin A1c levels between baseline and one year by subgroup of patients with non-insulin treated type 2 diabetes Values are means standard deviations
Control group n152 Meter group, less intensive self monitoring n150 Meter group, more intensive self monitoring n151 P value for interaction 082 729 102 730 124 001 103 770 113 770 111 -001 101 735 102 723 093 -012 085 748 102 733 084 -015 080 741 103 725 101 -016 073 767 120 749 108 -018 073 090 718 098 721 105 003 080 761 111 761 124 -001 110 685 066 690 070 004 064 761 105 741 091 -020 087 718 111 709 094 -009 072 766 110 746 107 -020 073 063 738 102 746 116 007 099 754 116 743 122 -011 114 730 096 722 076 -008 084 750 109 737 104 -013 080 757 121 743 116 -013 077 734 080 714 078 -020 067 086 753 111 748 116 -005 102 732 102 752 134 020 102 751 109 732 092 -019 088 707 063 712 073 005 056 771 119 743 113 -028 074 700 064 716 073 016 056
Variable Duration of diabetes 36
months: Baseline Follow-up Change 36 months: Baseline Follow-up Change Baseline therapy Diet only: Baseline Follow-up Change Oral drug therapy: Baseline Follow-up Change Health status EQ-5D: Diabetes 36 months: Baseline Follow-up Change Diabetes 36 months: Baseline Follow-up Change Absent: Baseline Follow-up Change Present: Baseline Follow-up Change
Oxfordshire practices was 9 2-24 and in 24 South Yorkshire practices was 8 3-16 Baseline personal and clinical characteristics were well balanced between the groups table 1 The median interquartile duration of diabetes was 30 years 18-64 years, mean SD age was 657 102 years, and mean SD level of haemoglobin A1c was 75 11 Only 57 126 patients were lost to follow-up, which did not differ between groups fig 1 Measurements for high density lipoprotein cholesterol levels were not obtained for 39 patients at baseline At follow-up, HbA1c measurements were not collected for two patients, blood pressure for five, cholesterol levels for 10, and high density lipoprotein cholesterol levels for 15
Primary outcome Table 2 shows the main results At 12 months no difference was found in HbA1c levels between the groups after adjustment for baseline
HbA1c levels P012 The mean difference in change in HbA1c levels from baseline to 12 months between the control group and less intensive intervention group not adjusted for baseline was -014 95 confidence interval -035 to 007 and between the control group and more intensive intervention group was -017 -037 to 003 Figure 2 shows the change in HbA1c levels over the 12 months of follow-up, with no evidence of differences in levels between groups over the period of follow-up P038 Secondary outcomes A significant difference was found in the change in total cholesterol levels between the three groups P0010 The mean difference in change in total cholesterol levels from baseline to 12 months between the control group and less intensive intervention group not adjusted for baseline was -006mmol/l -026 to 014 and between the control group and more intensive intervention group was -023 -043 to -004 No differences were found in the other secondary outcome measures table 2 Within the prespecified subgroups no significant interactions were found with allocated group table 3 Hypoglycaemia During the trial one or more grade 2 hypoglycaemic episodes were experienced by 14 patients in the control
group, 33 in the less intensive intervention group, and 43 in the more intensive intervention group 22183, P0001 Only one patient in the control group experienced a grade 3 hypoglycaemic episode Use of meter Patients allocated to less intensive self monitoring were significantly more likely to persist with use of the meter than those allocated to more intensive self monitoring Ninety nine 67 of those receiving the less intensive intervention and 79 52 of those receiving the more intensive intervention continued to use the meter at least twice a week for the 12 months of the study P0012; fig 3 Among those who continued to use a
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Diabetes related complications
No use of blood glucose meter After adjustment for baseline values Median 36 months EQ-5D score 0814 Paired data for EQ-5D score available for 384 patients
intensive intervention groups compared with a repeated measures analysis of variance
RESULTS Between January 2003 and December 2005, 453 patients with non-insulin treated type 2 diabetes from 48 practices in Oxfordshire and South Yorkshire were randomised to one of three interventions fig 1: usual care n152, less intensive self monitoring, using a blood glucose
meter and advice to contact doctor for interpretation of the results n150, and more intensive self monitoring, with a blood glucose meter and training in interpreting the results n151 The median range number of patients per practice recruited in 24
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Proportion of patients persisting with use of meters 2 tests weekly
10 08 06 04 02 0 0
Further analyses Later papers will report on quality of life, cost effectiveness, and subgroup and more detailed multivariate analyses DISCUSSION No significant improvement in glycaemic control was found after 12 months in patients with non-insulin treated type 2 diabetes using self monitoring of blood glucose levels when compared to those not self monitoring No evidence was found of a significantly different impact of self monitoring on glycaemic control when comparing subgroups of patients defined by duration of diabetes, therapy, diabetes related complications, and EQ-5D score Also no evidence was found that more intensive compared with less intensive monitoring led to differences in glycaemic control Strengths and weaknesses of the study In this study patients were
independently randomised, with concealed allocation of measurement of the main outcome and a low loss to follow-up Participants were drawn from a well defined sampling frame and the reasons for exclusion were fully recorded Recruitment targets were revised after baseline data on haemoglobin A1c levels in the first 245 randomised patients indicated that the standard deviation had been overestimated in the original power calculations9 We did not, however, change the proposed power or significance levels Participants diabetes was reasonably well controlled and although most were not using a meter a minority had had experience of their use Both these factors may have limited scope for further improvement in glycaemic control However, the participants were representative of well controlled noninsulin treated patients with type 2 diabetes in the community who are the target group for current recommendations of up to twice daily self monitoring and testing after meals17 18 Designing a trial to evaluate self monitoring of blood glucose levels is complex because it must include an educational component on the use and interpretation of testing for the intervention group,19 whereas advice on
improving self care must be offered to the comparison group3 We tackled these issues by providing a common structure for interventions, incorporating standardised good care in all three arms of the trial within which nurses discussed issues of glycaemic control, assessed either by HbA1c levels or self monitoring of blood glucose, and its role in setting and monitoring self care goals9 The stepwise approach to the interventions across the three arms of the trial allowed examination of what aspects of the intervention, if any, were responsible for improved outcomes Recent consensus guidelines have based recommendations for self monitoring of blood glucose levels on a theoretical potential to better self manage glycaemic control20 21 We incorporated self monitoring of blood glucose into a framework that, based on psychological theory, should have optimised its effect Careful specification, training, and monitoring of consultations ensured that the allocated interventions were delivered as
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Less intensive self monitoring with blood glucose meter More intensive self monitoring with blood glucose meter P0012 3 6 9 12
Time months
Fig 3 | Adherence to minimal
level of self monitoring of blood glucose levels using a meter
meter, the mean number of readings over 12 months was significantly higher among patients receiving the more intensive intervention compared with those receiving the less intensive intervention P0022; fig 4 Eight patients in the control group started using self monitoring of blood glucose
Changes in hypoglycaemic and lipid lowering drugs No differences were found between the groups in the proportions of patients prescribed an increase in hypoglycaemic drugs between baseline and 12 months In the control group 45 30 patients had increased drugs compared with 43 29 in the less intensive intervention group and 48 32 in the more intensive intervention group One patient in the control group, four in the less intensive intervention group, and five in the more intensive intervention group were using insulin therapy by 12 months No differences were found between groups in the proportions of patients where hydroxymethyl glutaryl coenzyme A reductase inhibitor statin treatment was increased or added to therapy Overall, 17 11 patients in the control group, 11 7 in the less intensive intervention group, and 19 13 in the more
intensive intervention group who were not taking a statin at baseline were taking a statin by 12 months
No of tests per week
6
5 P0022 Less intensive self monitoring with blood glucose meter More intensive self monitoring with blood glucose meter 3 0 0
4
3
6
9
12 Time months
Fig 4 | Frequency of self monitoring of blood glucose levels using a meter, by randomisation group
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planned,22 although some patients in the less intensive intervention group may themselves have adopted a more intensive monitoring approach Despite an intervention based on standards of best clinical practice and underpinned by appropriate psychological theory, we found no convincing evidence of an effect on glycaemic control
Strengths and weaknesses in relation to other studies Comparisons with early trials of blood glucose monitoring are of limited relevance because of their small size, the large quantity of blood required to be read by older meters, and the skill required for their use However, more recent trials have been carried out with meters utilising technologies that require smaller amounts of blood and simplified procedures for
testing Our findings support those of a recent small trial using standardised counselling for both intervention and control groups The trial reported a non-significant reduction in HbA1c levels of 02 in the intervention group compared with the control group23 Our findings, however, conflict with the findings of two of the largest trials of self monitoring of blood glucose to date One of these trials reported a significant decrease in HbA1c level of 03 in the intervention group compared with the control group24 However, over 30 of those randomised were lost to follow-up and missing values were not imputed, which might lead to bias In addition, initial specific training in use of a blood glucose meter was not matched by additional training for the control group, although all patients received dietary advice regardless of randomisation A second trial reported a reduction in HbA1c level of 046 in the intervention group compared with the control group Standardised counselling supporting lifestyle modification was, however, only provided to the self monitoring group25 This type of educational support for self management in itself has been estimated as improving HbA1c levels by 02626
Meaning of the study Fewer people in our trial allocated to more intensive self monitoring compared with less intensive self monitoring continued testing; previous studies have found that trying to understand blood glucose measurements may lead to frustration when results do not fall into a pattern, or cease to be of interest when they are entirely predictable27 Patients with reasonably well controlled diabetes do not need active encouragement to use a meter The increased recording of hypoglycaemia in the self monitoring arms may be a result of an increased awareness of low blood glucose levels from using the meter rather than a true biochemical difference between groups Although no improvement in glycaemic control was observed, a small but significant improvement was found in total cholesterol levels with the self monitoring intervention This finding is consistent with an increased intensity of self management in these groups, possibly mediated through increased dietary adherence or through taking lipid lowering drugs more regularly
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Unanswered questions and future research Recent systematic reviews have estimated a benefit of 04 from self monitoring,2
and on this basis a previous study has estimated an incremental cost of 4500 6650; 8880 to 15 515 per quality of life year gained Our estimates of the size of effect on HbA1c levels suggest that it is probable that the previous study underestimated the cost per quality of life year gained A comprehensive economic evaluation with cost effectiveness estimates will be detailed in a future report Evidence of benefit from self monitoring of blood glucose for other patient groups is stronger Large trials of management of patients with type 1 diabetes have incorporated self monitoring of blood glucose as an essential part of self management28 29 Self monitoring for insulin treated patients with type 2 diabetes is accepted practice, although the evidence base requires further work and optimisation of its use may be possible However, routine self monitoring of blood glucose for patients with reasonably well controlled non-insulin treated type 2 diabetes seems to offer, at best, small advantages; is not well accepted; and the cost, effort, and time involved in the procedures may be better directed to supporting other health related behaviours Current guidelines for the use of self monitoring
of blood glucose among patients with reasonably well controlled non-insulin treated type 2 diabetes should be reviewed
We thank the patients who took part in this study and their doctors for support and help W Hardeman and I Hobbis contributed to the development of the intervention protocols and prepared and led some of the training sessions for the nurses M McKinnon and J Donnelly helped train the nurses and L Rosmovitz carried out external review of interventions Contributors: AF, A-LK, and AN had the original idea for the study and wrote the trial protocol with PY, DF, and RH AF, AW, DF, and A-LK developed the trial measures and intervention PY was trial statistician and analysed the data AW, AF, AC, and EG managed the trial AF wrote the first draft of the manuscript with AN and A-LK and all members of the writing group reviewed and commented on the final manuscript AF is guarantor of this paper The DiGEM Trial Group Writing committee: AF, AW, EG, PY, DF, AC, RH, A-LK, and AN Investigators: AF, AN, A-LK, D Mant, S Ziebland, DF, A Gray, PY, and RH Steering committee: N Stott chair, AF, AN to 2005, S Sutton, H Tewson, D Chapman, H Hearnshaw, E Goyder from 2005, P Glasziou from
2005, M Jiwa 2004 to 2005, and M Gordon from 2005 Intervention development: AW, AF, DF, A-LK, and MP Selwood Coordinating Centres: Oxford AW to 2005, trial coordinator, AC trial manager, PY trial statistician, J Simon health economist, and A Fuller data manager; Sheffield Vivienne Walker local trial administrator Data monitoring committee: C Baigent chair, J Levy, and K Wheatley Research nurses Oxford MP Selwood, H Kirlow, M Chapman, and S Turner; Sheffield A Casbolt, K Dobson, A Willert, A Roberts, and H Wood Central laboratory: K Islam Funding: The trial was funded by the NHS and the National Insitute for Health Research health technology assessment programme The opinions expressed in this report are not necessarily those of the Department of Health Abbott Diabetes Care provided blood glucose meters Optium AF was supported by an NHS research and development career development award from 2001-5 AW was supported by a Rhodes scholarship Competing interests: None declared Ethical approval: This study was approved by the Oxfordshire Research Ethics Committee B 002059
1 Wild S, Roglic G, Green A, Sicree R, King H Global prevalence of diabetes: estimates for the year 2000 and
projections for 2030 Diabetes Care 2004;27:1047-53 Coster S, Gulliford MC, Seed PT, Powrie JK, Swaminatham R Selfmonitoring in type 2 diabetes mellitus: a meta-analysis Diabet Med 2000;17:755-61 page 7 of 8
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WHAT IS ALREADY KNOWN ON THIS TOPIC
Self monitoring of glucose for non-insulin treated patients with diabetes is costly but may improve glycaemic control Although some observational studies have suggested benefits, the results of randomised trials have been inconclusive
16
17
WHAT THIS STUDY ADDS
It is not necessary to routinely recommend self monitoring of blood glucose in reasonably well controlled patients with non-insulin treated type 2 diabetes
18
19 3 Welschen LMC, Bloemendal E, Nijpels G, Dekker JM, Heine RJ, Stalman WAB, et al Self-monitoring of blood glucose in patients with type 2 diabetes who are not using insulin: a systematic review Diabetes Care 2005;28:1510-7 Sarol JN Jr, Nicodemus NA Jr, Tan KM, Grava MB Self-monitoring of blood glucose as part of a multi-component therapy among noninsulin requiring type 2 diabetes patients: a meta-analysis 19662004 Curr Med Res Opin 2005;21:173-84 Karter AJ, Parker MM,
Moffet HH, Spence MM, Chan J, Ettner SL, et al Longitudinal study of new and prevalent use of self-monitoring of blood glucose Diabetes Care 2006;29:1757-63 Martin S, Schneider B, Heinemann L, Lodwig V, Kurth J, Kolb H, et al Self-monitoring of blood glucose in type 2 diabetes and long-term outcome: an epidemiological cohort study Diabetologia 2006;49:271-8 Farmer AJ, Neil A Variations in glucose self-monitoring during oral hypoglycaemic therapy in primary care [letter] Diabet Med 2004;22:511 Davidson MB Counterpoint: self-monitoring of blood glucose in type 2 diabetic patients not receiving insulin: a waste of money Diabetes Care 2005;28:1531-3 Farmer A, Wade A, French DP, Goyder E, Kinmonth AL, Neil A The DiGEM trial protocol–a randomised controlled trial to determine the effect on glycaemic control of different strategies of blood glucose self-monitoring in people with type 2 diabetes [ISRCTN47464659] BMC Fam Pract 2005;6:25 EuroQol Group EuroQol: a new facility for the measurement of health related quality of life Health Pol 2001;16:199-208 Leventhal H, Nerenz DR, Steele DJ Illness representations and coping with health threats In: Baum A, Taylor SE, Singer JE, eds Handbook of
psychology and health Hillsdale, NJ: Erlbaum, 1984:219-52 Hardeman W, Griffin S, Johnston M, Kinmonth AL, Wareham NJ Interventions to prevent weight gain: a systematic review of psychological models and behaviour change methods Int J Obes Relat Metab Disord 2000;24:131-43 Strecher VJ, Seijts GH, Kok GJ, Latham GP, Glasgow R, DeVellis B, et al Goal setting as a strategy for health behavior change Health Educ Q 1995;22:190-200 National Institute for Clinical Excellence Management of type 2 diabetes: management of blood glucose London: NICE, 2002 Hardeman W, Sutton S, Griffin S, Johnston M, White AJ, Wareham NJ, et al A causal modelling approach to the development of theory-
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based behaviour change programmes for trial evaluation Health Educ Res 2005;20:676-87 Turner RC, Cull CA, Frighi V, Holman RR Glycemic control with diet, sulfonylurea, metformin, or insulin in patients with type 2 diabetes mellitus: progressive requirement for multiple therapies UKPDS 49 UK Prospective Diabetes Study UKPDS Group JAMA 1999;281:2005-12 Bergenstal RM, Gavin III JR The role of self-monitoring of blood glucose in the care of
people with diabetes: report of a global consensus conference Am J Med 2005;1189, suppl 1:1-6 Gerich JE Clinicians can help their patients control postprandial hyperglycemia as a means of reducing cardiovascular risk Diabetes Educator 2006;32:513-22 Franciosi M, Pellegrini F, De Berardis G, Belfiglio M, Di Nardo B, Greenfield S, et al Self-monitoring of blood glucose in non-insulintreated diabetic patients: a longitudinal evaluation of its impact on metabolic control Diabet Med 2005;22:900-6 Owens DR, Barnett AH, Pickup J, Kerr D, Bushby P, Hicks D, et al Blood glucose self-monitoring in type 1 and type 2 diabetes: reaching a multi-disciplinary consensus Diabetes Primary Care 2004;6:398-402 American Diabetes Association Standards of medical care in diabetes-2006 Diabetes Care 2006;29suppl 1:S4-42 Bellg AJ, Borrelli B, Resnick B, Hecht J, Minicucci DS, Ory M, et al Enhancing treatment fidelity in health behavior change studies: best practices and recommendations from the NIH Behavior Change Consortium Health Psychol 2004;23:443-51 Davidson MB, Castellanos M, Kain D, Duran P The effect of self monitoring of blood glucose concentrations on glycated hemoglobin levels in diabetic
patients not taking insulin: a blinded, randomized trial Am J Med 2005;118:422-5 Guerci B, Drouin P, Grange V, Bougneres P, Fontaine P, Kerlan V, et al Self-monitoring of blood glucose significantly improves metabolic control in patients with type 2 diabetes mellitus: the autosurveillance intervention active ASIA study Diabetes Metab 2003;29:587-94 Schwedes U, Siebolds M, Mertes G Meal-related structured selfmonitoring of blood glucose: effect on diabetes control in noninsulin-treated type 2 diabetic patients Diabetes Care 2002;25:1928-32 Norris SL, Lau J, Smith SJ, Schmid CH, Engelgau MM Selfmanagement education for adults with type 2 diabetes: a metaanalysis of the effect on glycemic control Diabetes Care 2002;25:1159-71 Peel E, Parry O, Douglas M, Lawton J Blood glucose self-monitoring in non-insulin-treated type 2 diabetes: a qualitative study of patients perspectives Br J Gen Pract 2004;54:183-8 Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications DCCT/EDIC Study Research Group Intensive diabetes treatment and cardiovascular disease in patients with type 1 diabetes N Engl J Med 2005;353:2643-53 DAFNE Study Group Training in
flexible, intensive insulin management to enable dietary freedom in people with type 1 diabetes: dose adjustment for normal eating DAFNE randomised controlled trial BMJ 2002;325:746
Accepted: 13 June 2007
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