EAL

H/A: Caloric Needs (2007)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To evaluate disease symptoms as predictors of acute weight loss (loss of over 5% of weight), by addressing two questions:

Do symptoms trigger an episode of acute weight loss?
Does HAART use decrease the impact of symptoms on risk of acute weight loss?

Inclusion Criteria:

None specifically mentioned
All consecutive calls that occurred 21 to 90 days after the previous call were included.

Exclusion Criteria:

Subsequent calls that occurred less than 21 days or over 90 days since previous call.

Description of Study Protocol:

Recruitment

Participants were enrolled in the Nutrition for Healthy Living longitudinal cohort study
This analysis includes information obtained from April 1995 through June 1999.

Design

Longitudinal cohort.

Intervention

Semi-annual clinic visits and telephone calls.

Statistical Analysis

A separate model for each symptom complex or GI symptom was created and a relative risk of acute weight loss was obtained, adjusted for confounders
Adjusted models were tested for effect modification by HAART
Severity of symptoms were also examined if predictive of weight loss
The population-attributable risk of symptoms on acute weight loss was also evaluated.

Data Collection Summary:

Timing of Measurements

Subjects attended semi-annual clinic visits and were telephoned every five weeks to obtain information about weight and recent symptoms.

Dependent Variables

Acute weight loss: Weight change between consecutive calls, measured on home scale

Independent Variables

Symptoms: Abdominal pain, cough, diarrhea, fever, loss of appetite, mouth sores, shortness of breath, skin rashes, trouble swallowing, vomiting and other symptoms
Dieting
Experience of depression using eight-item screening instrument
Behavioral history since last clinic examination
Medical history, including antiretroviral use, CBC, albumin level, CD4 lymphocyte count, HIV load and caloric intake.

Control Variables

Demographic data.

Description of Actual Data Sample:

Initial N: 415 subjects and 2,814 telephone interviews
Attrition (final N): 415 subjects, 77.8% male
Age: Mean age 39.9±7.7 years
Ethnicity: 69.6% white, 21.0% black, 9.4% other
Other relevant demographics: 33.4% had CD4 lymphocyte count below 200 cells per mm³
Anthropometrics: 41.7% were using HAART
Location: Boston and Providence.

Summary of Results:

Table Three: Determinants of Acute Weight Loss in 415 HIV-Infected Men and Women

Variable in Model	Relative Risk (95% Confidence Interval)	P-Value
Oral Symptom Complex or Trouble Swallowing	1.6 (1.04-2.4)	0.03
Nervous System Symptom Complex	2.4 (0.9-6.6)	0.09
HIV Transmission Risk Factor of Male-Male Sexual Contact	0.7 (0.5-0.96)	0.03
Albumin Level (g/dL)	0.7 (0.5-1.00)	0.05
HAART and Diarrhea Interaction	--	0.04

Other Findings

Acute weight loss occurred across 4.5% of intervals and among 24% of individuals
Patients reported more than one symptom before 58% of telephone intervals
The most common symptoms or symptom complexes before intervals were diarrhea (21% of patients), anorexia (17% of patients), upper respiratory symptoms (16%), skin symptoms (12%) and abdominal pain (12%)
Trouble swallowing (6%) and oral symptoms (7%) were less common
Risk of acute weight loss was significantly increased when oral symptoms or trouble swallowing were present and it was decreased when highly active antiretroviral therapy (HAART) was used or when diarrhea was not present.

Author Conclusion:

Even when HAART is being administered, clinicians should remain vigilant regarding weight loss, oral symptoms and trouble swallowing.

Funding Source:

Government:	NIDDK, NIH, Centers for AIDS Research (CFAR)
University/Hospital:	Tufts University School of Medicine, Tufts-New England Medical Center

Reviewer Comments:

Authors note that participants may not have easily recalled all recent symptoms and start dates or responded if they were severely ill, depressed or impoverished, but depression and poverty were not associated with acute weight loss.

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?		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?		Yes
	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?	Yes
	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?		No
	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.)	No
	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?		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?	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?		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