EAL

DM: Carbohydrate Management Strategies (2014)

Citation:

Speight J, Amiel SA, Bradley C, Heller S, Oliver L, Roberts S, Rogers H, Taylor C, Thompson G. Long-term biomedical and psychosocial outcomes following DAFNE (Dose Adjustment for Normal Eating) structured education to promote intensive insulin therapy in adults with sub-optimally controlled type 1 diabetes. Diabetes Res Clin Pract. 2010; 89: 22-29.

PubMed ID: 20399523

Study Design:

Prospective Cohort Study

Class:

B - Click here for explanation of classification scheme.

Quality Rating:

NEUTRAL: See Quality Criteria Checklist below.

Research Purpose:

To determine the extent to which improvements in biomedical and physiological outcomes observed six and 12 months post-DAFNE training have been sustained in the long term.

Inclusion Criteria:

Participation in DAFNE study prior to this follow-up study.

Exclusion Criteria:

Not giving consent to participate in current study
Use of insulin pump.

Description of Study Protocol:

Recruitment

All participants were recruited from previous randomized controlled trial.

Design

A cohort design follow-up of original trial participants at a mean of 44 months (range of 37 to 51 months) in hospital diabetes clinics in three English health districts.

Original study participants were given the Audit of Diabetes-Dependent Quality of Life (ADDQoL) questionnaire to assess long-term impact of the original training
HbA1c was assessed to see long-term BG control
Both were compared to original data as well as 12-month post-training levels
Weight and blood lipids were also assessed.

Blinding Used

Implied with measurements.

Intervention

Previous participation in DAFNE training course to learn management of type 1 diabetes by adjusting insulin dosing to CHO content of the meal. This follow-up study assessed current quality of life measures and compared them to original and 12-month post-intervention levels.

Statistical Analysis

Kruskal-Wallis: To explore differences between DAFNE centers at 44 months for continuous data
?²: To explore differences between DAFNE centers at 44 months for categorical data and differences between follow-up participants and non-participants for baseline data and 12-month categorical data
Mann-Whitney U statistics: Compared differences between follow-up participants and non-participants for baseline data and 12-month continuous data
ANOVA: Used for primary outcomes, differences were analyzed using mixed model with time to analyze differences within-subjects and treatment group. Supported by pair T-tests or unpaired tests as appropriate post-hoc.
Secondary outcomes were analyzed using paired and unpaired T-tests as appropriate
To investigate the generalizability of the findings data were also analyzed using the last observation carried forward (LOFC).

Data Collection Summary:

Timing of Measurements

Follow-up took place mean 44 months (range 37 months to 51 months) post-intervention.

Dependent Variables

Long-term control of BG: HbA1c
Quality of life measured using Audit of Diabetes-Dependent Quality of Life (ADDQoL) questionnaire to assess long-term impact of the original training
Weight
Blood lipids.

Independent Variables

Participation in single DAFNE training course.

Description of Actual Data Sample:

Initial N: A total of 141 completed DAFNE in the original trial. Of those, 136 completed the 12-month follow-up.
Attrition: A total of 104 (52 males, 52 females) completed the 44-month follow-up
Age: Mean age 44±9 years
Other relevant demographics: Mean duration of diabetes was 20±10 years
Anthropometrics: At 44 months, there were only two differences noted between centers (HbA1c and weight)
Location: United Kingdom.

Summary of Results:

Key Findings

Primary and Secondary Outcomes in Original DAFNE Trail Cohort at Baseline, 12 and 44 months Post-DAFNE

Variables	Cohort at Baseline	Cohort at 12 Months	Cohort at 44 Months	Baseline to 44 Months	12 Months to Baseline
	Mean (SD)			Statistical Values (T)
HbA1c	9.32 (1.15)	8.75 (1.23)	8.96 (1.22)	-2.92**	2.14*
ADDQoL: Weighted impact of DM on quality of life	-1.89 (1.44)	-1.22 (1.08)	-1.26 (1.28)	5.31***	0.99
ADDQoL: Present quality of life	1.04 (0.89)	1.41 (0.98)	1.40 (0.88)	-2.54	0.88

* P<0.05

** P<0.01

*** P<0.001

Other Findings

HbA1c remained significantly improved from prior to the trial; however, there was a deterioration between HbA1c soon after DAFNE training and 44 months
At 44 months, mean improvement in HbA1c from baseline was 0.36% (9.32±1.1% to 8.96±1.2%, P<0.01), remaining significant but deteriorated from 12 months (P< 0.05)
For each of the QoL outcomes, the significant improvement observed following DAFNE training were maintained at 44-months follow-up
Improvements in QoL seen at 12 months were sustained at 44 months [e.g., impact of diabetes on dietary freedom was -1.78±2.33 at 44 months vs. -4.27±2.94 at baseline, (P<0.0001) vs. 1.80±2.32 at 12 months, NS]
Similar results were obtained using the last observation carried forward for patients not supplying follow-up data
There was a significant mean increase in weight between baseline and 44 months (+1.5kg, P<0.01), most of which (1.15kg) was incurred between 12 and 44 months (P<0.05)
While there was a significant improvement in HDL-cholesterol from baseline (1.55±0.46mmol per L) to 44 months (1.67±0.53mmol per L), there were no significant differences in total cholesterol and triglycerides.

Author Conclusion:

The impact of a single DAFNE course on glycemic control is still apparent in the long term. To maximize both the short-term and long-term benefits for glycemic control, DAFNE may be modified to include structured follow-up.

Funding Source:

Not-for-profit

Diabetes UK, DAFNE Collaborative

Other non-profit:

Reviewer Comments:

At 44 months, there were only two differences noted between centers (HbA1c and weight)
Authors were unable to obtain follow-up at 44 months for the entire cohort.

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	Yes
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	Yes

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
2.	Was the selection of study subjects/patients free from bias?		Yes
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	Yes
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	Yes
	2.4.	Were the subjects/patients a representative sample of the relevant population?	Yes
3.	Were study groups comparable?		???
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	Yes
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	???
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	N/A
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	???
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	N/A
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		No
	4.1.	Were follow-up methods described and the same for all groups?	Yes
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	No
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	???
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		Yes
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	Yes
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	Yes
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	N/A
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		Yes
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	N/A
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	Yes
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	Yes
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	Yes
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	N/A
	6.6.	Were extra or unplanned treatments described?	N/A
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	N/A
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		Yes
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	Yes
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	Yes
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	Yes
	7.5.	Was the measurement of effect at an appropriate level of precision?	Yes
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	No
	7.7.	Were the measurements conducted consistently across groups?	Yes
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		Yes
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	Yes
	8.2.	Were correct statistical tests used and assumptions of test not violated?	Yes
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	Yes
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	Yes
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	Yes
	8.6.	Was clinical significance as well as statistical significance reported?	Yes
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	N/A
9.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	Yes
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes