H/A: Monitoring of Food Intake (2009)
To examine the clinical course of patients with HIV infection and the relationship among weight maintenance, dietary intake and standardized dietary counseling.
Patients with HIV infection with or without an AIDS-defining illness and a favorable performance status (defined as asymptomatic or with minimal symptoms).
- Chronic diarrhea (defined as "persisting for more than 30 days and/or requiring medication")
- Infection of the central nervous system
- Severe gastrointestinal symptoms.
Recruitment
Patients who met the inclusion criteria from an HIV clinic in a county hospital in a large metropolitan area.
Design
- Prospective cohort study
- Eligible patients had baseline and six-month assessments of nutritional status, including:
- Anthropometric measurements
- Energy and nutrient intake assessment based on seven-day food records
- Gastrointestinal symptom assessment (based on standardized questionnaire developed to assess factors influencing weight loss as a result of cancer)
- Immunologic function measuring the lymphocyte T-cell subpopulations (ratio of CD4 to CD8)
- Serum immunoglobulin levels
- Serum cholesterol.
- Each patient 's primary physician provided clinical management
- Patients were monitored to determine clinical outcome.
Intervention
- Standardized dietary counseling goals based on seven-day food record analysis were to maintain body weight and address energy deficiency (less than 30kcal per kilogram actual or pre-illness weight and nutrient deficiencies defined as less than 66% of the RDA)
- Enteral supplements were prescribed if needed to address deficiencies. No enteral tube feedings or parenteral nutrition were provided to the study patients.
Statistical Analysis
- Chi-square analysis and Student's T-test were used to determine differences between groups
- A multivariate Cox proportional hazards regression model was used to determine the best predictors of clinical outcome.
Timing of Measurements
At baseline and six months.
Dependent Variables
- Total energy intake (seven-day food records)
- Nutrient intake (seven-day food records, considered to be deficient in nutrients if intake less than 66% of the RDA)
- Gastrointestinal symptoms (based on standardized questionnaire developed previously to assess factors influencing weight loss as a result of cancer)
- Anthropometric measurements (current weight, height, triceps skinfold thickness and mid-arm circumference) Weighed without shoes, clothed, on same printing beam scale according to standardized protocol
- Immunologic function as lymphocyte T-cell subpopulations (ratio of CD4 to CD8) and serum immunoglobulin levels
- Serum cholesterol
- Progression from HIV infection to AIDS.
Independent Variable
Standardized dietary counseling to address weight maintenance and to address identified energy and nutrient deficiencies.
Initial N: 108 HIV-infected patients
Attrition (final N): 108, 65 with HIV only (96% male) and 43 with AIDS (88% male)
Age: Mean age±standard error: HIV only, 35 years±3 years; AIDS, 37 years±3 years
Ethnicity: Not described.
Other relevant patient characteristics:
| HIV Only | AIDS | ||
| CD4 cell count (cells/mm3) | 376±39 | 114±19 | P<0.01 |
| Azidothymidine use (%) | 40 | 81 | P<0.01 |
| Body weight (% of usual) | 101±1 | 98±2 | |
| Serum albumin level (g/L) | 42±1 | 40±1 | |
| Serum cholesterol level (mmol/L) | 4.29±0.18 | 3.72±0.23 | P<0.01 |
Location: UCLA School of Medicine, Harbor-UCLA Medical Center, Torrance, Calif.
| Clinical Parameters |
HIV only Baseline vs. Six Months |
AIDS Baseline vs. Six Months |
Significance (P value) |
|
Total energy intake (kcal/day) |
Baseline: 2,175±87 Six months: 2,185±87 |
Baseline: 2,275±91 Six months: 2,287±205 |
Not significant |
|
Micronutrient intake |
Vitamin B6: 74% of RDA Zinc: 65% of RDA Folic acid: 57% of RDA |
Vitamin B6: 74% of RDA Zinc: 65% of RDA Folic acid: 57% of RDA |
Not significant |
|
Body weight (%usual) |
Baseline: 10±11 Six months: 100±1 |
Baseline: 98±2 Six months: 96± 2 |
P <0.05 (HIV vs. AIDS) |
|
Immunologic: CD4 cell count (cells/mm3) |
Baseline: 398±46 Six months: 340±45 |
Baseline: 103±23 Six months: 72± 23 |
P<0.05 (HIV vs. AIDS) |
|
Cholesterol (mmol/L)
|
Baseline: 4.32±18 Six months: 4.26±16 |
Baseline: 3.98±16 Six months: 3.69±0.26 |
P<0.05 (HIV vs. AIDS) |
Other Findings
There were no significant differences in cholesterol intakes between groups.
At baseline, total energy intake (based on 30kcal/kg usual body weight) was adequate in both HIV and AIDS patients (101%±4% and 103%±5%).
Despite dietary counseling and continued maintenance of energy intake, body weight, serum cholesterol level and CD4 level progressively decreased.
Dietary saturated fat intake was inversely related to serum cholesterol level (r=0.56, P<0.1) in both groups.
Life-table analyses indicated strong clinical benefit associated with favorable ratio of CD4 to CD8 (median even-free survival more than 900 days vs 266 days for favorable vs. unfavorable tertile groups; P<0.001), weight maintenance (median even-free survival=656 days vs. 301 days for high- vs. low-tertile percentage usual body weight; P<0.01), and high serum cholesterol level (median event-free survival=915 days vs. 254 days for high- vs. low-tertile groups; P<0.001).
The ratio of CD4 to CD8 (P<0.001) and percentage usual weight loss (P<0.001) were identified as independent factors best predictive of event-free survival.
In patients with HIV infection, weight loss is independently prognostic of clinical outcome, and development of a low serum cholesterol level is not favorable. As weight loss progresses despite apparently adequate energy intake, use of conventional criteria to identify energy requirements for counseling is unlikely to prevent weight loss or to improve clinical outcome. Dietary interventions early in the course of the disease, combined with increased target levels for energy intake, should be considered.
The authors did not state if there were any withdrawals. Regression table states n=108 (initial sample size) but unknown if all data was collected on all patients.
Intervention was standard dietary counseling to address energy and nutrient deficiencies. The results section states: "...few patients met the criteria for aggressive dietary counseling or intervention." It would be important to know in that subgroup if significant increases in intakes were found and if there were differences in outcomes in the group who received nutritional intervention.
BMI would have been better indicator of nutritional status than percentage usual body weight.
No statement was made about body composition measures, although those were noted in the methods. Was there a difference in TSF and MAC between groups?
Six months may not have been long enough to see changes in outcomes based on dietary intakes or weight.
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Quality Criteria Checklist: Primary Research
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| 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? | 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? | No | |
| 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? | ??? | |
| 4.1. | Were follow-up methods described and the same for all groups? | ??? | |
| 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%.) | ??? | |
| 4.3. | Were all enrolled subjects/patients (in the original sample) accounted for? | ??? | |
| 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? | No | |
| 6.6. | Were extra or unplanned treatments described? | No | |
| 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? | ??? | |
| 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? | ??? | |
| 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? | 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 | |