H/A: Physical Activity (2009)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To measure the prevalence of and associations among impairments, activity limitations and participation restrictions in persons living with HIV in British Columbia to inform support and care programs, policy and research.

Inclusion Criteria:

Members of the British Columbia Persons with AIDS Society.

Exclusion Criteria:

Only respondents providing information about their CD4 levels were included in the analysis.

Description of Study Protocol:


Cross-sectional population-based sample of persons living with HIV in British Columbia was obtained through an anonymous survey sent to members of the British Columbia Persons with AIDS Society.


Cross-sectional study. 

Statistical Analysis

  • Rates of impairments, activity limitations and participation restrictions among the participants were compared across three categories of CD4 cell counts using a chi-squared test for categorical variables and the Kruskal-Wallis test for continuous variables
  • Bonferroni corrections for multiple comparisons were done for each item
  • Associations were measured in three ways: Impact of types of impairment on social restriction, impact of specific limitations on social restriction and independent association of overall impairments and limitations on restriction levels
  • Logistic regression was used to measure associations with social restriction, while ordinal logistic regression was used to measure associations with a three-category measure of restriction level
  • All models were stratified on CD4 levels, with separate models built for individuals with counts below 200 cells per mm3, and adjusted for age, gender, employment and years since diagnosis and risk category.
Data Collection Summary:

Timing of Measurements

The survey addressed the experience of physical and mental impairments, and the experience and level of activity limitations and participation restrictions.

Dependent Variables

  • Diagnosed conditions measured by whether or not a doctor had ever diagnosed them with any of 13 conditions, including depression, schizophrenia, bipolar disorder and post-traumatic stress disorder
  • Subjects identified their experiences during the past month using checklists of impairments, activity limitations and participation restrictions that included space to identify unlisted items
  • Mental impairments included reduced libido, poor concentration, poor appetite, chronic fatigue, decreased endurance, decreased memory, impaired cognition and aphasia
  • Internal impairments included diarrhea, gastric reflux, shortness of breath, constipation, wasting, weakness, vomiting and incontinence
  • Sensory impairments included headaches, altered sensations, nausea, mouth pain and decreased vision
  • Neuromusculoskeletal impairments included altered muscle tone, stiff joints, seizures, hemiparesis and paraparesis
  • Activity limitations were addressed by asking about managing 15 daily activities
  • Participation restrictions were addressed by asking about levels of restriction in 10 social, student and cultural roles 

Independent Variables

HIV infection.

Control Variables

  • Age
  • Gender
  • Employment
  • Years since diagnosis
  • Risk category.
Description of Actual Data Sample:
  • Initial N: 1,508 HIV-positive individuals who had consented to receive mailings from the British Columbia Persons with AIDS Society
  • Attrition (final N): Survey was returned by 762 participants (50.5%). 614 provided information about their CD4 levels and were included in the analysis. 76.6% of the participants were male.
  • Age: 63.9% were between the ages of 30 and 49 years
  • Ethnicity: 88.7% were white
  • Anthropometrics: A comparison of all members who received the survey and the subset who responded found a similar distribution of age and a similar proportion identifying as Aboriginal, but the proportion of females was higher among the total population than among the subset of respondents
  • Location: British Columbia, Canada.
Summary of Results:



CD4 < 200 CD4 Between  201 and 500 CD4 > 500

Statistical Significance of Group Difference


64 (52.0)  183 (59.2) 110 I(61.5) 0.238

General anxiety

11 (8.9)

34 (11.0)

14 (7.8)


Post-traumatic stress 6 (4.9) 18 (5.8) 13 (7.3) 0.677
Panic disorder 8 (6.5) 35 (11.4) 12 (6.7) 0.124
Median number of impairments (IQR) 9 (5, 13) 7 (2.5, 12) 7 (3, 12) 0.006
Percentage with any impairment 120 (97.6) 285 (92.5) 161 (89.9) 0.041
Pain: None 25 (20.7)  82 (29.4) 48 (28.4) 0.079
Pain: Little/Mild 35 (28.9) 89 (31.9) 62 (36.7) --
Pain: Moderate/Severe 61 (50.4) 108 (38.7) 59 (34.9) --
Median number of activity limitations (IQR) 3 (1, 7) 3 (1, 7) 2 (1, 5) 0.015
Percentage with any activity limitation 108 (87.8) 236 (77.4) 137 (76.5) 0.031
Median number of participation restrictions (IQR) 7 (4, 9) 7 (3, 9) 7 (3, 9) 0.251
Percentage with any participation restrictions 121 (98.4) 278 (91.5) 161 (89.9) 0.017

Other Findings

Over 90% of the population experienced one or more impairments, with one third reporting over 10.

Prevalence of activity limitations and participation restrictions was 80.4% and 93.2%, respectively.

The presence of social restrictions was most closely associated with mental function impairments (odds ratio: 7.0 for impairment vs. no impairment, 95% confidence interval: 4.7 to 10.4).

All limitations were associated with social restriction.

Among those with less than 200 CD4 cells per mm3, odds of being at a higher restriction level were lower among those on antiretrovirals (odds ratio: 0.3 for antiretrovirals vs. no antiretrovirals, 95% confidence interval: 0.1 to 0.9), while odds of higher restriction were increased with higher limitation (odds ratio: 3.6 for limitation score of one to five vs. no limitation, 95% confidence interval: 0.9 to 14.2; odds ratio: 24.7 for limitation score more than five vs. no limitation, 95% confidence interval: 4.9 to 125.0).

Among those with more than 200 CD4 cells per mm3, the odds of higher restriction were increased with higher limitation (odds ratio: 2.7 for limitation score of one to five vs. no limitation, 95% confidence interval: 1.4 to 5.1; odds ratio: 8.6 for limitation score more than five vs. no limitation, 95% confidence interval: 3.9 to 18.8), as well as by additional number of impairments (odds ratio: 1.2 for every additional impairment, 95% confidence interval: 1.1 to 1.3). 

Author Conclusion:

This study revealed a strikingly high prevalence of impairments, activity limitations and participation restrictions among a population-based sample of people living with HIV in British Columbia. The complicated interplay among these categories requires further study, but it is clear that interventions designed to help overcome activity limitations and social support programs are required, especially those addressing mental impairments and depression. While impairments and limitations are not always reversible, innovative programs that help people living with HIV address these challenges may help to decrease the subsequent high rates of participatory restrictions experienced. Antiretroviral treatments have enabled the prolongation of the lives of people who are HIV-infected; now we need to give due attention to optimizing the quality of these extended lives.

Funding Source:
Government: Canadian Working Group on HIV and Rehabilitation (CWGHR), Canadian Institutes for Health Research
Foundation associated with industry:
Reviewer Comments:

Subset of respondents not representative of association membership in regards to gender. Questionnaire not shown to be valid or reliable. Authors note the following limitations:

  • Somewhat homogeneous nature of the participants, which affects the generalizability of findings to other populations
  • Survey sent to members who were consenting to receive mail
  • Limitations in the nature of self-reported diagnoses.
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? No
  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? N/A
  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? No
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? N/A
  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.) N/A
  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? N/A
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? No
  7.5. Was the measurement of effect at an appropriate level of precision? ???
  7.6. Were other factors accounted for (measured) that could affect outcomes? ???
  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