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MNT: Comparative Effectiveness of MNT Services (2009)

Citation:

Caggiula AW, Watson JE, Kuller LH, Olson MB, Milas NC, Berry M, Germanowski J. Cholesterol-lowering intervention program. Effect of the Step I diet in community office practices. Arch Intern Med. 1996; 156: 1205-1213.

PubMed ID: 8639015
 
Study Design:
Randomized clinical trial.
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To test the feasibility of cholesterol lowering in physician office practices using the National Cholesterol Education Program Adult Treatment Panel I guidelines.

Inclusion Criteria:
  • None specified for physician practices
  • All patients in the physician office practices were to be considered for cholesterol screening and placed in one of three categories: Patients who would not be screened, patients whose screening was postponed or patients for whom screening was ordered
  • Once screened, patients would be placed in one of two categories: No treatment indicated or treatment indicated based on the ATP I algorithm.
Exclusion Criteria:

None specifically mentioned for physician practices or patients.

Description of Study Protocol:

Recruitment

Physician practices were recruited from communities in Western Pennsylvania and West Virginia, based on response to a mail survey, as well as announcements in medical society newsletters, presentations to local societies and referral by patients.

Several practices did not proceed to randomization in Phase Two and additional practices had to be recruited.

Design

Randomized clinical trial. 

Intervention

  • Three models (Usual Care, Office Assisted and Nutrition Center) for implementing the National Cholesterol Education Program Adult Treatment Panel I guidelines were tested over an 18-month period
  • After Phase One (Usual Care Model), participating physician practices were randomized to Office Assisted or Nutrition Center (Phase Two)
  • All three models were to use the same tracking and monitoring system to standardize patient screening and follow-up procedures
  • Phase One (Usual Care): After the orientation session, study activities were initiated over a six-week period
  • Phase Two (Office Assisted): Physician practices used the nutrition intervention materials
  • Phase Two (Nutrition Center): Physician practices referred patients to the nutrition center for treatment, where they were seen individually by a nutritionist for three visits, usually monthly, and met in groups.

Statistical Analysis

  • Descriptive statistics were used to examine demographic and cholesterol response variables
  • Categorical variables such as gender, race and risk factors were analyzed using chi-square tests
  • Continuous variables and comparisons between models were examined by two-sample student T-tests
  • ANOVA was used for comparisons among the three models
  • All patients who were initially treated for hypercholesterolemia were included in end-point analyses regardless of whether a follow-up cholesterol measurement was obtained 60 days after treatment was initiated.
Data Collection Summary:

Timing of Measurements

Cholesterol measurements taken at baseline, after Phase One and after Phase Two.

Dependent Variables

  • Cholesterol measurements through standard laboratory methods
  • Patient satisfaction measured with survey at the end of Phase Two.

Independent Variables

  • Three models (Usual Care, Office Assisted and Nutrition Center) for implementing the National Cholesterol Education Program Adult Treatment Panel I guidelines were tested over an 18-month period
  • After Phase One (Usual Care Model), participating physician practices were randomized to Office Assisted or Nutrition Center (Phase Two).

Control Variables

  • Baseline value of total cholesterol
  • Patient data collected through the initial assessment form, cholesterol laboratory result form, the clinical evaluation form and the follow-up form.
Description of Actual Data Sample:

Initial N 

22 practices in Phase One and 23 in Phase Two. 

Attrition (Final N) 

  • 22 physician practices in Phase One (450 adults, 190 men and 260 women) and 23 physician practices in Phase Two (480 adults, 184 men and 296 women)
  • 296 subjects in Office Assisted and 184 in Nutrition Center.

Age and Ethnicity 

  • Office Assisted men (N=136): 52.5±12.7 years; 79.9% white, 20.1% African American
  • Office Assisted women (N=160): 55.9±13.1 years; 85.0% white, 15.0% African American
  • Nutrition Center men (N=48): 48.3±12.8 years; 93.6% white, 6.4% African American
  • Nutrition Center women (N=136): 53.8±14.5 years; 85.3% white, 14.7% African American.

 

Anthropometrics 

Men treated in Nutrition Center Model were significantly younger than in Office Assisted. Authors note that there were some significant differences between groups in comparison of Phases One and Two (data not reported).

Location

Western Pennsylvania and West Virginia.

 

Summary of Results:

 

Variables

Mean Change in Total Cholesterol (mmol per L) Percentage Change
Office Assisted: Patients not on Medications (N=262)  -0.31 -4.6

Nutrition Center: Patients not on
Medications (N=169)

-0.54

-7.8

Office Assisted: Patients on Medications (N=34) -0.95 -12.2
Nutrition Center: Patients on Medications (N=15) -0.86 -10.8
Office Assisted: All Patients (N=296) -0.38 -5.5

Nutrition Center: All Patients (N=184)

-0.56

-8.0

Other Findings

  • Phase 1 (Usual Care): In the patients who were not taking lipid-lowering medication, the mean change in serum cholesterol level from baseline to the first remeasurement was 0.14mmol per L (5.4mg per dL, P<0.01), or 2.2%
  • Phase 1 (Usual Care): In the patients who were taking medication, the mean change was 0.58mmol per L (22.4mg per dL, P<0.05), approximately four times greater than that observed in patients who were not taking medication
  • In the patients who were not taking lipid-lowering medication, the mean cholesterol response was significantly different between the three models (P<0.01)
  • Serum cholesterol levels declined by 0.14mmol per L (5.4mg per dL) in the Usual Care Model, by 0.31mmol per L (12mg per dL) in the Office Assisted Model, and by 0.54mmol per L (20.9mg per dL) in the Nutrition Center Model
  • Two factors (length of time to follow-up measurement and change in weight) were independently related to cholesterol response across all models
  • African Americans demonstrated a significantly smaller response than whites in the Usual Care Model, while men demonstrated greater declines in serum cholesterol levels than women in the Office Assisted Model
  • Patient satisfaction was very favorable in both enhanced conditions; however, those treated in the Nutrition Center Model were more satisfied with program components (P<0.05)
  • While not significantly different, reported time spent by physicians with patients was highest in the Usual Care Model (15.2 minutes) and lowest in the Office Assisted Model (13.5 minutes)
  • The maximum recorded time spent with patients was highest in the Office Assisted Model (60 minutes) and lowest in the Nutrition Center Model (30 minutes).
Author Conclusion:

In this study, the mean change in cholesterol level obtained in any model was less than 10%. For many patients, a response of this magnitude would not be considered clinically significant. However, we do not interpret these results to mean that the dietary approach to cholesterol lowering is ineffective. What they do suggest is that even with highly motivated physicians, lifestyle therapies such as nutrition are difficult to implement in usual practice settings, which are not typically designed to manage long-term programs for behavioral changes. The changes observed in the Nutrition Center Model provide evidence that greater cholesterol responses can be obtained with specialized lipid-lowering programs. These programs should support the use of therapies beyond the Step I diet, as well as weight loss. Physicians can best contribute to these therapies by motivating patients and ensuring that they are effectively referred.

Funding Source:
Government: NHLBI
Reviewer Comments:

Inclusion/exclusion criteria for physician practices are not mentioned. Additional recruitment required at end of Phase One. Significant differences between groups at baseline of Phase Two as well as between Phases One and Two. Groups were not similarly sized. Authors note that sample of physician practices may not be representative.

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? ???
  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? No
  2.2. Were criteria applied equally to all study groups? ???
  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? ???
3. Were study groups comparable? No
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) No
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? No
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  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? N/A
  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? Yes
  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%.) Yes
  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? N/A
  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? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  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? Yes
  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? Yes
  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? Yes
  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