Patient Education: lessons
learnt from ABACUS
Dr Katharine Barnard CPsychol AFBPsS
May 2013
Imagine
• You have a puzzle that you cannot solve
• Every day you think carefully about the puzzle but there is
no solution
• Some days the solution to the puzzle is tantalisingly close
• Other days the solution is elusive
• You ask others if they have the solution but they do not
Imagine
• If you had to live life like this every single day ...
• For the rest of your life …
• And that your life depended on …
your being able to solve that puzzle
Sword of damocles
• Go blind
• Foot amputation
• Kidney failure
• Cardiovascular disease
Burden of Diabetes
People feel:
• Isolated
• Lonely
• Ugly
• Afraid
• Burned-out
Bolus Calculations
• You have insulin
treated diabetes
• You eat carbohydrates
• You need an insulin
bolus every time you
eat CHO’s
• You have an I:CHO
ratio, an ISF and a
target range
Example One
• Current blood glucose = 5.5
• I:CHO ratio = 1 unit of insulin for 10g CHO
• ISF = 1 unit of insulin to reduce by 2
• Target range = 4-7
• 100g CHO meal
Example One
• Current blood glucose = 5.5
• I:CHO ratio = 1 unit of insulin for 10g CHO
• ISF = 1 unit of insulin to reduce by 2
• Target range = 4-7
• 100g CHO meal
• Units of insulin required = 10 units
Example Two
• Current blood glucose = 5.5
• Add exercise after meal = 60 minutes
• 60 minutes’ exercise will drop bg by 6
• I:CHO ratio = 1 unit of insulin for 10g CHO
• ISF = 1 unit of insulin to reduce by 2
• Target range = 4-7
• 100g CHO meal
Example Two
• Current blood glucose = 5.5
• Add exercise after meal = 60 minutes
• 60 minutes’ exercise will drop bg by 6
• I:CHO ratio = 1 unit of insulin for 10g CHO
• ISF = 1 unit of insulin to reduce by 2
• Target range = 4-7
• 100g CHO meal
• Units of insulin required = 7 units
Let’s Be More Realistic
• What if:
• Current bg level is 9.3
• I:CHO ratio = 1 unit of insulin for 8g CHO
• Meal contains 67g CHO
• Doing 45 minutes of exercise
• ISF = 1 unit to reduce by 2
• How many units now?
Let’s Be More Realistic
• What if:
• Current bg level is 9.3
• I:CHO ratio = 1 unit of insulin for 8g CHO
• Meal contains 67g CHO
• Doing 45 minutes of exercise
• ISF = 1 unit to reduce by 2
• Units of insulin required = 7.5 units
Maths Check
“I tried to check the maths.
I have grade A "A level" maths (passed with
100%) and was originally accepted to
Cambridge to study physics and despite this,
when I checked your numbers, I felt overwhelmed and went to pieces and honestly can't
do the sums”.
13
Margin of Error
• ‘Best guess’ approach
• ‘Little bit wrong’ every bolus dose
• What would be the cumulative effect of all of those errors?
Hidden Difficulties
• 45% of UK adults have only primary school maths (aged
>10 yrs)
• Approximately 20% of adults lack basic numeracy skills
• Diabetes is non-discriminatory
• GCSE maths (aged 16 yrs) is required to calculate a bolus
dose accurately
• CHO counting alone is insufficient
Does Use of an Insulin Bolus Advisor Improve
Glycemic Control in Patients Not Achieving
Optimal Control Using MDI?
Results of the Automated
Bolus Advisor Control and
Usability Study (ABACUS)
Ralph Ziegler, David A. Cavan, Iain Cranston, Katharine Barnard,
Jacqueline Ryder, Claudia Vogel, Christopher G. Parkin, Walter
Koehler, Iris Vesper, Bettina Petersen, Matthias Axel Schweitzer,
Robin S. Wagner
Manual Bolus Calculation Creates
Obstacles for Patients
• Discourages adherence to therapy:
– Manual bolus calculation is complex, difficult, time-consuming, and
requires mathematical skills and competence in carbohydrate
counting
– Patients may skip a bolus or rely on empirical estimates, which can
lead to severe clinical consequences1,2
• Compromises patient safety:
– Manual calculation does not account for the effect of active insulin
remaining from previous bolus, which can lead to inappropriate
“stacking” of boluses, resulting in hypoglycemia3
1. Pickup J et all. Diabetes Care 2002;25:593-598.
2. Bode BW et al, Diabetes Metab Res Rev 2002;18 (Suppl 1):S14-S20.
3. DeWitt DE and Hirsch IB. JAMA 2003;289(17):2254-2264.
Study Overview
• Primary Objective:
– Determine if use of an insulin bolus advisor improves glycemic
control
• Study Goal:
– Decrease HbA1c by >0.5% in each participant
•
Secondary Objectives:
– Improvements in glycemic variability
– Bolus advisor use and adherence to MDI rules
– Changes in psychosocial factors
– Frequency and severity of hypoglycemia
Accu-Chek® Aviva Expert
The Accu-Chek® Aviva Expert blood
glucose meter:
• Contains an integrated bolus advisor
• Presents meal and correction bolus
recommendations based upon
current bG value, planned CHO
intake and patient-specific therapy
parameters stored in the device
• Stores blood glucose and meal
information in an electronic diary
Study Protocol
• All Participants
– 6-month randomised trial using Accu-Chek Aviva Expert meter
(EXP) vs Accu-Check Aviva Nano (CNL)
– Baseline CHO Counting/MDI competency assessments and
remedial training based on identified deficits (knowledge/DAFNE
plates)
– Psychosocial Assessments at baseline and study end
– Structured SMBG (3-Day, 7-Point Profiles) at beginning, midpoint
and end of study
– SMBG data downloaded and reviewed at every visit to adjust
treatment parameters
– Continuous Glucose Monitoring (CGM) in “blinded” mode
(approximately 50% of subjects) at beginning, midpoint and end
of study
Study Timeline
Total intervention is 24 weeks
Visit 1 Visit 3
Visit 5
Screening Start
Start CGM BA
0
Visit 2
Train and
Randomize
Visit 4
Tx Check
(phone)
Visit 7
Visit 9
Therapy
Check
Therapy
Check
Study End
4
12
24
Visit 6
Start CGM
Visit 8 Visit 10
Start CGM
Type 1 and Type 2
>7.5 HbA1c
MDI Therapy
Training in MDI/CHO Counting within past 2 years
Call
Interventions
• Control Participants (CNL)
– Monitored blood glucose and manually calculated bolus insulin
dosages based on test results
– Insulin dosage parameters were checked/adjusted at all visits
• Intervention Participants (EXP)
– Monitored blood glucose and used Bolus Advisor to calculate
bolus insulin dosages
– Insulin dosage parameters in Bolus Advisor were
checked/adjusted and updated in device at all visits
Participant Disposition
Screened
n=229
Drop-outs
n=11
8 eligibility not met
3 withdrew consent
Randomized
n=218
Control
Intervention
n=113
n=105
Drop-outs
n=20
9 withdrew consent
4 noncompliant
3 withdrew consent
and noncompliant
1 surgery/illness
3 lost to follow up/other
Drop-outs
n=5
Completers
Completers
n=93
n=100
2 noncompliance
1 withdrew consent
and noncompliant
1 surgery/illness
1 pregnancy
%Completers Achieving >0.5% HbA1c Reduction
All Completers
• Bolus advisor use was associated with a 63% greater chance for achieving HbA1c
reduction of >0.5%
• Average HbA1c reduction of -1.2% in both groups
Glycemic Variability (CGM)
Mean Amplitude of Glucose Excursion (MAGE)
3-Day Profile Days: All CGM Completers
Changes in MAGE correlated with SD of glucose
values (r = 0.87) and were independent of education
level, diabetes duration, duration of MDI and gender
Frequency of bG <50 mg/dL / 2.8 mmol/L
Values <50 mg/dL / 2.8 mmol/L (%)
All Completers
8
p=0.5880
p=0.1251
p=0.0764
p=0.0519
p=0.4698
p=0.1639
p=0.8876
p=0.8703
50 75
86 90
85 91
85 91
85 91
86 91
86 92
7
6
5
4
3
2
1
0
-1
N=
86 92
V1-2
V2-3
V3-4
Control
V4-5
V5-6
V6-7
V7-8
V8-9
Intervention
Use of the Bolus Advisor not associated with increased
frequency of severe hypoglycemia
CHO and MDI Knowledge
Assessments and Checklists
CHO and MDI Knowledge
Association with Baseline HbA1c
High competency (Perfect Score) in CHO/MDI knowledge
was associated with lower HbA1c values
28
Carbohydrate Counting Assessment
DAFNE Plates
CHO Counting Competency
Completers
Control (N=113)
Baseline
1.6 (10.1) / 14.6 (9.7)
MME (Accuracy) g
MMAE (Variability) g
V9
1.0 (9.7) / 13.3 (9.9)
Intervention (N=105)
Baseline
1.0 (10.1) / 15.2 (9.0)
V9
0.3 (7.1) / 12.4 (7.3)
Significant improvement in MMAE (- 2.8 (8.2), p<0.01) and a trend
towards improvement in MME in the EXP group but no change in CNL
Use of MDI Rule Sets
Control
Patient-recorded bolus calculations from 3-day profiles were
checked to determine if their stated I:CHO and ISF rules were used
in a mathematically correct manner for each bolus calculation
Bolus Advisor Utilization
Intervention
All
(n=105)
Advice used during study (SD), %
73.5 (21.9)
Advices sought per day (SD), n
2.8 (1.2)
Advices accepted per day (SD), n
2.5 (1.1)
Advices modified per day (SD), n
0.3 (0.5)
Doses adjusted up per day (SD), n
0.1 (0.2)
Doses adjusted down per day (SD), n
0.2 (0.4)
• High percentage of use, overall; however daily frequency of advice
sought decreased significantly (-0.2 per day, p<0.01) by study end
• Patients were twice as likely to reduce their insulin vs. increase dose
Bolus Advisor Utilization
Changes of Parameters
• Significantly more EXP than CNL patients had changes in their insulin
sensitivity factor (ISF) settings at Week 4 (24.5% vs. 10.8%, p<0.05)
and Week 12 (29.3% vs. 8,6%, p<0.01).
• The number of different ISF settings used during the day were
increased significantly in EXP vs. CNL patients at all visits (p<0.05).
• The number of ISF settings significantly increased longitudinally from
baseline to study end in EXP but not CNL patients (p<0.05).
• The number of changes in I:CHO settings showed a similar not
statistically significant trend, with more EXP than CNL patients
receiving I:CHO changes at Week 4 (35.7% vs. 25.8%, p=NS) and
Week 12 (44.4% vs. 33.0%, p=NS).
• The number of I:CHO settings significantly increased longitudinally in
EXP but not CNL patients from the start to the end of the study
(p<0.05).
Treatment Satisfaction
Improvement in DTSQ score from Baseline: Completers
• EXP patients reported significantly greater improvement in
treatment satisfaction from baseline than CNL patients
• Baseline for CNL and EXP: 27.9 (6.1) vs. 28.0 (6.1); p=NS
Summary
•
More EXP participants achieved >0.5% HbA1c
reduction than CNL
•
Use of Bolus Advisor was a/w reduced glycemic
variability but not higher frequency of severe hypos
•
Overall, participants sought/accepted bolus advice
around 75% of the time
•
Participants using manual bolus calculation followed
their “Rule Sets” only 26% to 47% of the time
•
Use of bolus advisor is a/w improved CHO
competency
•
Participants who used the bolus advisor had more
frequent changes in and more different I:CHO and ISF
parameters
Key Messages
• CHO-counting and MDI skills at baseline are variable
(despite education – so should such education include an
assessment of skills learnt?)
• There was an improvement in CHO estimation in the
Expert group and an overall benefit in the Expert group
• Bolus calculators can facilitate greater diabetes control
• People use devices differently - use should ‘best fit’ with
individual needs and personal circumstances
Key Questions:
• Do people with diabetes really understand and value the
importance of accurate CHO counting?
• How easy is it to fit accurate CHO counting into daily living
realistically?
• Do we support self-efficacy in CHO counting in the personal
context of diabetes?
• Is it possible to put education into context of everyday
living against competing priorities?
Diabetes Puzzle
Still looking for the answer!
k.barnard@soton.ac.uk