EAL

H/A: Caloric Needs (2007)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To determine the relative importance of various factors in the causation of wasting related to human immunodeficiency virus.

Inclusion Criteria:

None specifically mentioned.

Exclusion Criteria:

None specifically mentioned.

Description of Study Protocol:

Recruitment

HIV-seropositive men were recruited from two London HIV centers.

Design

Longitudinal study.

Statistical Analysis

Relative contributions were assessed by linear structural modeling based on multiple regression, expressing results as path coefficients for individual relationships
The interrelatedness of explanatory variables was investigated when values of the partial regression coefficients were of unexpected magnitude, had high standard errors or were non-significant, despite high R².

Data Collection Summary:

Timing of Measurements

Metabolic and clinical measurements were collected at 105 time points over a three-year period between 1990 and 1993.

Dependent Variables

Energy intake measured with seven-day weighed food records (N=48), seven-day food diaries (N=31) and 24-hour recalls (N=17)
Total energy expenditure measured using doubly-labeled water over 14 days at 51 time points in 27 of 33 men
Resting energy intake measured by indirect calorimetry
Rate of change in weight calculated from serial weight measurements
CD4 count
Energy balance
Activity-related energy expenditure
Physical activity level.

Independent Variables

HIV infection
Clinical status and stage of infection, physiologic and functional status measured with Hospital Anxiety and Depression Scale and Nottingham Health Profile
Presence of opportunistic infections
Appetite scored on a three-point scale
Mood.

Description of Actual Data Sample:

Initial N: 33 men
Attrition (final N): 33
Age: Median, 35 years; range, 28 to 62 years
Ethnicity: Not mentioned
Other relevant demographics: Median CD4 count at entry was 40/mm³; range, zero to 660
Location: United Kingdom.

Summary of Results:

	Mean	Minimum	Median	Maximum
Weight (kg, N=105)	66.2	35.7	66.8	85.3
BMI (N=105)	20.8	12.8	20.3	26.4
Weight change (kg/Month, N=102)	-0.70	-8.00	0.00	4.40
Energy intake (kcal/kg/Day, N=96)	37.8	9.0	38.5	71.8
Protein intake (g/Day, N=78)	88.9	20.0	87.0	187.0
REE (kcal/kg/Day, N=103)	26.3	21.1	26.0	39.3
Total EE (kcal/kg/Day, N=51)	42.1	28.1	42.3	58.6

Other Findings

The primary determinant of energy balance was energy intake (R=0.80)
Total energy expenditure made a minor contribution to energy balance (R=-0.04)
Total energy expenditure was primarily determined by activity level (R=0.91), which itself was negatively related to the presence of opportunistic infection and CD4 count
Energy intake was related to activity level (R=0.28) and appetite (R=0.30), which were closely interrelated (R=0.59).

Author Conclusion:

The present results were obtained in the era before the impact of HAART. Although the precise quantitative contributions attached to each of these factors may now differ, their relative importance is likely to remain unchanged and should focus therapeutic approaches to prevent or reverse wasting.
Therapy should be targeted to those areas that contribute most significantly to wasting
Our findings suggest that maintenance of adequate energy intake is of paramount importance. This, together with appropriate programmed physical exercise, is a way in which individuals can take control of their own health, although there is a need to guard against extremes such as deliberate overeating and excessive physical training.
Minimizing the presence of opportunistic infections, the anorexic effects of medication and the coexistence of depression are clearly also potential targets for intervention.

Funding Source:

Reviewer Comments:

Inclusion and exclusion criteria were not well defined
Not all measurements made in all subjects.

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)	N/A
	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)	N/A

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?		N/A
	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?	N/A
	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?	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?	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?		N/A
	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?	N/A
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	N/A
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	N/A
	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?	???
	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?		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)?	N/A
	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?		???
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	No
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