H/A: Physical Activity (2009)
The purpose of this study was to determine what level of association exists between physical activity and CD4+ cell counts and HIV-RNA viral load in HIV-infected individuals.
- 18 years of age or older
- Able to read and understand English at a sixth-grade level
- Receiving care at the investigator's referring clinic.
Subjects were recruited with the use of flyers and through a referring medical doctor
- Cross-sectional; descriptive, correlational
- Convenience sample; subjects were selected from the pool of HIV-infected individuals being treated at a local hospital.
Blinding used (if applicable)
Not stated; implied for laboratory measurements
Intervention (if applicable)
Strength of association between variables of interest was evaluated using Pearson's correlation.
Timing of Measurements
- All laboratory results were less than 12 weeks old
- Three days of measurement of physical activity with a wrist actigraph.
Measured by wrist actigraphy (Ambulatory Monitoring, Inc., Ardsley, NY) on the non-dominant hand for three days. Test-retest reliability was high (r=0.98).
- Physical activity index: Calculated as the percentage of time units where activity levels were recorded at greater than zero
- Mean physical activity: Calculated as the average minutes of physical activity performed per day over the data collection period
- Acceleration index: A measure of physical activity intensity.
The following surveys were also administered:
- Pittsburgh Sleep Quality Index
- Epworth Daytime Sleepiness Scale
- Piper Fatigue Scale
- State-Trait Anxiety Index
- Perceived Stress Scale.
CD4+ counts and HIV-RNA loads were obtained from health care providers through retrospective chart review
66 male and female subjects
Attrition (final N)
- African American 92%
- Caucasian 5%
- Hispanics 3%.
Representative of the HIV-infected population of the study location
Other relevant demographics
All subjects were on anti-retroviral medications (type was not listed)
Columbia, South Carolina
|Physical Activity Index||Mean Physical Activity||Acceleration Index|
|HIV-RNA viral load||
CD4+ cell count
- Mean CD4+ cell count: 412±271; range = 8 to 1,140
- Viral load: 38,571±84,437; range undetectable to 5160,000 viral copies
- Average minutes of physical activity: 144±31 minutes per day; range 43 to 193 minutes; low, moderate and high intensity activities are all included in this value
- Physical activity index averaged 84±8.4% and acceleration index averaged -0.22.
- Physical activity index and mean physical activity levels were not associated with symptom severity, sleep quality, daytime sleepiness, fatigue, state anxiety, trait anxiety and perceived stress
- A significant inverse relationship was found between mean physical activity level and viral load (P=0.047)
- A significant inverse relationship was also observed between physical activity index and viral load (P=0.0061)
- Neither mean physical activity nor physical activity index scores correlated with CD4+ cell counts
- Acceleration index, a measure of physical activity intensity, showed no correlation to viral load or CD4+ cell counts.
- This study demonstrates that physical activity, independent of intensity and stage of illness, is inversely associated with HIV-RNA vial load values
- Data suggests that people participating in more physical activity have lower viral loads
- The current study demonstrates that regular physical activity may also be beneficial for HIV patients.
Limitation as stated by authors: Design which does not allow for determination of a causal relationship.
Reviewer comments: Not stated how many men and how many women participated, just the total number of participants; did not state the types of medications the participants were on; no anthropometrics were given, thus there is no indication if subjects were under- or overweight.
Quality Criteria Checklist: Primary Research
|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|
|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?||N/A|
|2.3.||Were health, demographics, and other characteristics of subjects described?||???|
|2.4.||Were the subjects/patients a representative sample of the relevant population?||Yes|
|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?||N/A|
|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%.)||N/A|
|4.3.||Were all enrolled subjects/patients (in the original sample) accounted for?||???|
|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?||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?||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?||N/A|
|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?||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)?||No|
|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|