MNT: Cost Effectiveness, Cost-benefit, or Economic Savings of MNT (2009)

Citation:

McGehee MM, Johnson EQ, Rasmussen HM, Sahyoun N, Lynch MM, Carey M. Benefits and costs of medical nutrition therapy by registered dietitians for patients with hypercholesterolemia. J Am Diet Assoc. 1995; 95: 1041-1043.

PubMed ID: 7657908
 
Study Design:
Retrospective Cohort Study
Class:
B - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To examine the effectiveness and cost of medical nutrition therapy (MNT) provided by registered dietitians in lowering serum cholesterol levels in patients with mild to moderate hypercholesterolemia. 

Inclusion Criteria:

Hospitals included: 

  • Massachusetts hospitals accredited by the Joint Commission
  • more than 100 beds
  • Ambulatory services provided
  • HMOs with dietitians on staff and providing outpatient care.

Subjects included: 

  • Outpatients
  • Primary diagnosis of hypercholesterolemia
  • No lipid-lowering medications
  • Ages 20 to 80 years
  • Seen for minimum of two visits by dietitian between January, 1990 and December, 1993.
Exclusion Criteria:

Hospitals: Pediatric, rehabilitation, Veteran's Affairs hospitals excluded.

Description of Study Protocol:

Recruitment

Data collected at 23 sites from 285 outpatients. Potential sites for data collection identified using the American Hospital Association Guide to the Health Care Field.

Design

Retrospective cohort study; cost-effectiveness analysis.

Blinding Used

Investigators blinded to source of data and names of subjects.

Intervention

Dietitian providing MNT to hypercholesterolemic patients to lower serum cholesterol.

Statistical Analysis

Methods/data analysis plan not reported.

Data Collection Summary:

Timing of Measurements

Eligible charts were pulled and screened for potential patients; selected chart of every third patient if there were more than 60 patients; every second patient if there were 31 to 60; all patients if there were 11 to 30 and all patients if there were less than 10. 

Dependent Variables

  • Initial and final serum cholesterol
  • Height, weight
  • Total counseling time (minues) with dietitian
  • Charge (dollars) to patient for nutrition. 

Independent Variables

MNT by Dietitian to reduce serum cholesterol.

 

Description of Actual Data Sample:
  • Initial N: 474
  • Attrition (final N): Complete information for N=285 (108 males, 177 females); those with incomplete data and not included in the analysis were younger (P<0.02) and heavier (P<0.004) than those included, but had similar serum cholesterol levels
  • Age: 51 (range, 22 to 79) years
  • Ethnicity: Not reported.
  • Location: Massachusetts, US.
Summary of Results:

Other Findings

  • Mean time with a dietitian was 134±77 minutes; mean number visits to dietitian was 4±3.8
  • Mean charge to patients was $162.80±131.40 (average of four visits) vs. annual cost of drug treatment of $1,450.00
  • Mean serum cholesterol reduction of 0.62mmol per L (approximately 8.6%); men showed greater reduction (10.7%) than women (7.2%)
  • 45% of total sample had more than or equal to 11% decrease in serum cholesterol; 24% had no reduction 
  • 22% of total population went from high (>6.2mmol per L) to borderline high (<5.2mmol per L to 6.2mmol per L) levels; 6% reduced their risk from high to desirable (<5.2mmol per L); and 7% of the sample decreased their level from borderline high to desirable. The remaining 65% of total population lowered cholesterol levels within the same classification range or showed no improvement. 
  • There was a significant correlation between serum cholesterol reduction and time spent with a dietitian (R=0.118, P<0.001), for as time spent with a dietitian increased, the greater serum cholesterol decreased. 

 

Author Conclusion:

Medical nutrition therapy provided by dietitians should be considered the initial step in an effective and low-cost approach in the management of patients with mild to moderate hypercholesterolemia. 

Funding Source:
Government: USDA
University/Hospital: Massechusetts General Hospital, Cambridge, Tufts University, MGH Institute of Health Professionals
Reviewer Comments:
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? 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? ???
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) N/A
  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.) No
  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? N/A
  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? N/A
  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? No
  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? No
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? ???
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? ???
  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? ???
  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? ???
  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? ???
  7.7. Were the measurements conducted consistently across groups? N/A
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? ???
  8.1. Were statistical analyses adequately described and the results reported appropriately? No
  8.2. Were correct statistical tests used and assumptions of test not violated? ???
  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)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? No
  8.6. Was clinical significance as well as statistical significance reported? ???
  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