H/A: Physical Activity (2009)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
  • To characterize physical performance in individuals with human immunodeficiency virus (HIV)
  • To examine group differences by pain and fatigue on a multivariate profile of disease, physical and psychologic symptoms.
Inclusion Criteria:
  • Seropositive for HIV
  • Receiving ambulatory care
  • Read and understand enough English to complete the questionnaires.
Exclusion Criteria:
  • Significant cardiovascular or pulmonary disease (myocardial infarction within the past six months, angina or dyspnea at rest)
  • Paraplegia, hemiplegia, severe peripheral neuropathy and any other major neurologic dysfunction.
Description of Study Protocol:


Patients were recruited from a public county outpatient AIDS facility in a large metropolitan area in the Southwest United States. Consecutive patients attending the AIDS clinic and who met the criteria were advised about the purpose of the study and invited to participate.


Cross-sectional study. 

Statistical Analysis

  • Descriptive statistics were computed for the sample as a whole and for subsamples based on pain and fatigue
  • Patients were grouped on the basis of pain and fatigue level
  • Three separate two-way MANOVA followed by univariate ANOVAs were used to examine group differences in disease indicators, physical performance levels and psychosocial measures
  • Two separate stepwise linear regressions were computed to examine the potential correlates of physical performance and quality of life.
Data Collection Summary:

Timing of Measurements

All measurements made on the same day. Subjects completed the self-report questionnaires followed by the physical performance tasks. The testing order of the physical performance tasks was randomized, except the six-minute walk was always completed last.

Dependent Variables

  • Physical performance tests: Series of 11 tasks that challenged physical function in both seated and standing positions
  • Self-report questionnaires for measures of pain (zero to 10 numerical rating scale), fatigue (Brief Fatigue Inventory), depression (Beck Depression Inventory) and perceived health status (Medical Outcomes Survey: HIV scale).

Independent Variables

HIV infection.



Description of Actual Data Sample:
  • Initial N: 100 outpatients (78 males and 22 females)
  • Attrition (final N): As above
  • Age: Mean age, 40.70±7.49 years.


  • 29 White, non-Hispanic
  • 54 African American, non-Hispanic
  • 13 Hispanic
  • Two Native American
  • Two Other.

Other Relevant Demographics

  • Mild fatigue, no pain (N=34) mean CD4 count: 373.06±366.40 cells per ml, viral load 68,316±180,323
  • Severe fatigue, no pain (N=12) mean CD4 count: 189.83±183.27 cells per ml, viral load 253,015±319,602
  • Mild fatigue, pain (N=22) mean CD4 count: 300.14±235.60 cells per ml, viral load 88,370±218,559
  • Severe fatigue, pain (N=28) mean CD4 count: 386.36±302.39 cells per ml, viral load 128,678±227,670.


Southwest United States.


Summary of Results:

Other Findings

  • Physical performance was compromised in a task-specific manner. As a group, patients' physical performance was much lower than that of age-equivalent healthy patients
  • There were no significant differences in hemoglobin levels, pain, fatigue, physical performance or quality of life measures between patients groups on the basis of CD4 counts
  • Patients took twice as long as healthy individuals on a belt-tie and four times as long on a sit-to-stand task and in six minutes walked 75% of the distance covered by healthy individuals
  • 50% of patients (N=50) had pain at the time of testing (mean 6.3±2.4) and 98% had fatigue (mean 5.4±2.3)
  • Multivariate analysis of variance showed pain had a greater influence on performance than fatigue
  • Pain, distance walked in six minutes, and unloaded forward reach accounted for 26% of the variability in quality of life (R=0.51, P<0.0001)
  • 62% of patients reported that their quality of life was moderately to severely affected by their disease (mean 55.05±21.71).
Author Conclusion:

Pain had a substantial impact on physical performance and quality of life among ambulatory human immunodeficiency virus patients. Fatigue also impacts physical performance. Compromised ability to perform certain physical tasks affects quality of life. Further investigation of the roles of these relevant variables should be investigated in path analyses.

Funding Source:
Reviewer Comments:
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) 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? 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? 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? 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? Yes
  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