EAL

H/A: Physical Activity (2009)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To compare physical activity levels between HIV-negative and HIV-positive injection drug users and between HIV-positive participants not on any treatment and participants on highly active antiretroviral therapy.

Inclusion Criteria:

Participants were in a substudy from the AIDS Linked to Intravenous Experiences (ALIVE) cohort.

Exclusion Criteria:

None specifically mentioned.

Description of Study Protocol:

Recruitment

Participants in a substudy of the AIDS Linked to Intravenous Experiences (ALIVE) Cohort, on ongoing study of HIV-negative and HIV-positive injection drug users. Recruitment methods were not described.

Design

Cross-sectional analysis of a cohort.

Statistical Analysis

Demographic characteristics were expressed as percentages within each group, while physical activity measurements were expressed as means
Chi-square P-values were presented for differences in proportions between the groups
Generalized linear models were used to obtain univariate means and to adjust for confounders (age, gender, employment and recent injection drug use).

Data Collection Summary:

Timing of Measurements

Patients were seen every six months. The substudy assessment took place immediately following their regular ALIVE clinic visit. Anthropometric measurements were obtained and a questionnaire was administered.

Dependent Variables

Anthropometric measurements
Physical activity assessed by interviewer-administered modified Paffenbarger physical activity questionnaire.

Independent Variables

HIV infection
HAART.

Control Variables

Age
Gender
Employment
Recent injection drug use
CD4 counts
Viral load
Various medical conditions
Alcohol use
BMI
Self-reported body habitus changes
Smoking.

Description of Actual Data Sample:

Initial N: 324 participants
Attrition (final N): 324.

Age and Ethnicity:

HIV-negative subjects (N=99): Mean age, 46.17±0.60 years; 96.97%, African American; 2.02%, Hispanic; 1.01%, White
HIV-positive subjects, no HAART (N=79): Mean age, 40.75±0.74 years; 96.15% African American; 1.28%, Hispanic; 2.56%, White
HIV-positive subjects, HAART (N=134): Mean age, 44.66±0.55 years; 93.98%, African American; 3.01%, Hispanic; 3.01%, White.

Other Relevant Demographics

Median CD4+ lymphocyte counts were similar among HIV-positive participants.

Anthropometrics

Participants in the substudy had similar characteristics to the ALIVE cohort participants.

Summary of Results:

Energy Expenditure (kcals) in the Various Physical Activities in the Study Participants

	HIV-negative (N=94)	HIV-positive, No Treatment (N=79)	HIV-positive, HAART (N=131)	Statistical Significance of Group Difference
Sleeping	524±23.2	471±24.5	501±23.1	0.33
Light activity	1,376±61.2	1,343±70.9	1,453±61.6	0.37
Moderate activity	811±78.9	664±86.5	678±84.7	0.44
Vigorous activity	438±108	623±128	267±98.8	0.03
Total energy expenditure	3,149±121	3,100±135	2,899±129	0.26

Other Findings

Women had lower vigorous activity levels than men and participants who were currently employed had higher vigorous and moderate and lower light activity levels than participants who were not employed.

Vigorous activity was lower among HAART participants than HIV-positive participants not on treatment (P=0.0018) and somewhat lower than HIV-negative participants (P=0.11).

Injection drug use and viral load were not associated with vigorous activity.

Energy expenditure in vigorous activity was also lower among HAART participants than both HIV-negative and HIV-positive participants not on treatment.

HIV-positive participants on HAART spend less time on vigorous activity independent of recent injection drug use.

Author Conclusion:

In summary, in this study population of inner city injection drug users, vigorous activity is less common in HIV-positive participants on HAART. More research is needed into the reasons and mechanisms for the lack of vigorous activities, including behavioral, psychological and physiological reasons. In the meantime, because of the overall health benefits of physical activity, recommendations in HAART patients may need to be refocused on more moderate physical activities.

Funding Source:

Government:

National Institute on Drug Abuse (DA10252, DA04334, DA08004), National Cancer Institute (5P20CA096256-02)

Reviewer Comments:

Inclusion/exclusion criteria and recruitment methods not well described. All physical activity habits were based on self-report. Numbers of study subjects reported differently throughout the paper.

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?	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)	Yes
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	Yes
	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?	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.)	Yes
	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?	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%.)	???
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	No
	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?		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?	No
	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?	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?	N/A
	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?	No
	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)?	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