Guangyong Zou

Using a single question to assess physical activity in older adults: a reliability and validity study

BackgroundSingle-item physical activity questions provide a quick approximation of physical activity levels. While recall questionnaires provide a more detailed picture of an individuals level of physical activity, single-item questions may be more appropriate in certain situations. The aim of this study was to evaluate two single-item physical activity questions (one absolute question and one relative question) for test-retest reliability, convergent validity, and discriminant validity, in a sample of older adults.MethodsData was obtained from the Project to Prevent Falls in Veterans, a fall risk-factor screening and modification trial. One question measured absolute physical activity (seldom, moderately, vigorously active) and one measured relative physical activity (more, about as, less active than peers). Test-retest reliability was examined using weighted Kappa statistics (κ) in a sample of 43 subjects. Validity was assessed using correlation coefficients (r) in participants who received clinical assessments (n = 159).ResultsThe absolute physical activity question was more reliable than the relative physical activity question (κ = 0.75 vs. κ = 0.56). Convergent validity, however, was stronger for the relative physical activity question (r = 0.28 to 0.57 vs. r = 0.10 to 0.33). Discriminant validity was similar for both questions. For the relative physical activity question, there was moderate agreement when this question was re-administered seven days later, fair to moderate/good associations when compared with indicators of physical function, and little to no associations when compared with measures hypothesized to be theoretically not related to physical activity.ConclusionsThe relative physical activity question had the best combination of test-retest reliability, convergent validity and discriminant validity. In studies requiring a measure of physical activity, where physical activity is not the primary focus and more detailed measures are not feasible, a single question may be an acceptable alternative.

Injurious Falls Are Associated with Lower Household but Higher Recreational Physical Activities in Community-Dwelling Older Male Veterans

Background: Physical activity (PA) and exercise have numerous beneficial effects in older adults. The effect of sustaining an injury from a fall on subsequent PA levels has received little research attention, even though about a quarter of older adults who fall sustain a serious injury. Even less is known about the effect of injurious falls on different PA categorizations. Objective: To examine the role of injurious falls on subsequent household and recreational PA levels in older community-dwelling males who were all Canadian veterans of World War II and the Korean War. Methods: Data from a fall risk-factor modification trial were used for the present study. Falls and related injuries were ascertained prospectively using fall calendars. A brief, valid and reliable PA interview for older adults (Phone-FITT) measured household and recreational PA approximately 1 year later. Covariates were measured as part of the screening questionnaire administered at the start of the study. Multiple linearregression models were computed using household and recreational PA as dependent variables. Results: The present study included 200 males with a mean age 81 years (SD = 3.8). Half of the participants fell at least once and about one third reported at least one injury resulting from a fall. Multivariable analyses indicated that household PA scores were 3.1 points lower (95% CI = –5.8 to –0.3, p = 0.03) and recreational PA scores were 3.4 points higher (95% CI = 0.1 to 6.7, p = 0.04) among persons who had one or more falls leading to injury compared to those who did not fall or had one or more falls without injury. Analyses were adjusted for age, baseline PA, self-rated health, foot problems, balance problems, inability to stand without using armrests, vision and memory. Conclusion: Categorization of PA type (household vs. recreational) suggests distinct differences in PA response following an injurious fall. Use of an overall PA measure would obscure this finding. Following further research, the results from this study may help in the design of preventive strategies to maximize physical activity in those who have sustained an injurious fall.

Effects of being uninsured or underinsured and living in extremely poor neighborhoods on colon cancer care and survival in California: historical cohort analysis, 1996—2011

BackgroundWe examined the mediating effects of health insurance on poverty-colon cancer care and survival relationships and the moderating effects of poverty on health insurance-colon cancer care and survival relationships among women and men in California.MethodsWe analyzed registry data for 3,291 women and 3,009 men diagnosed with colon cancer between 1996 and 2000 and followed until 2011 on lymph node investigation, stage at diagnosis, surgery, chemotherapy, wait times and survival. We obtained socioeconomic data for individual residences from the 2000 census to categorize the following neighborhoods: high poverty (30% or more poor), middle poverty (5-29% poor) and low poverty (less than 5% poor). Primary health insurers were Medicaid, Medicare, private or none.ResultsEvidence of mediation was observed for women, but not for men. For women, the apparent effect of poverty disappeared in the presence of payer, and the effects of all forms of health insurance seemed strengthened. All were advantaged on 6-year survival compared to the uninsured: Medicaid (RR = 1.83), Medicare (RR = 1.92) and private (RR = 1.83). Evidence of moderation was also only observed for women. The effects of all forms of health insurance were stronger for women in low poverty neighborhoods: Medicaid (RR = 2.90), Medicare (RR = 2.91) and private (RR = 2.60). For men, only main effects of poverty and payers were observed, the advantaging effect of private insurance being largest. Across colon cancer care processes, Medicare seemed most instrumental for women, private payers for men.ConclusionsHealth insurance substantially mediates the quality of colon cancer care and poverty seems to make the effects of being uninsured or underinsured even worse, especially among women in the United States. These findings are consistent with the theory that more facilitative social and economic capital is available in more affluent neighborhoods, where women with colon cancer may be better able to absorb the indirect and direct, but uncovered, costs of care.

Mediation of the effects of living in extremely poor neighborhoods by health insurance: breast cancer care and survival in California, 1996 to 2011

BackgroundWe examined the mediating effect of health insurance on poverty-breast cancer care and survival relationships and the moderating effect of poverty on health insurance-breast cancer care and survival relationships in California.MethodsRegistry data for 6,300 women with breast cancer diagnosed between 1996 and 2000 and followed until 2011 on stage at diagnosis, surgeries, adjuvant treatments and survival were analyzed. Socioeconomic data were obtained for residences from the 2000 census to categorize neighborhoods: high poverty (30% or more poor), middle poverty (5%-29% poor) and low poverty (less than 5% poor). Primary payers or health insurers were Medicaid, Medicare, private or uninsured.ResultsEvidence of survival mediation was observed for women with node negative breast cancer. The apparent effect of poverty disappeared in the presence of Medicare or private health insurance. Women who were so insured were advantaged on 8-year survival compared to the uninsured or those insured by Medicaid (OR = 1.89). Evidence of payer moderation by poverty was also observed for women with node negative breast cancer. The survival advantaging effect of Medicare or private insurance was stronger in low poverty (OR = 1.81) than it was in middle poverty (OR = 1.57) or in high poverty neighborhoods (OR = 1.16). This same pattern of mediated and moderated effects was also observed for early stage at diagnosis, shorter waits for adjuvant radiation therapy and for the receipt of sentinel lymph node biopsies. These findings are consistent with the theory that more facilitative social and economic capital is available in low poverty neighborhoods, where women with breast cancer may be better able to absorb the indirect and direct, but uncovered, costs of care. As for treatments, main protective effects as well as moderator effects indicative of protection, particularly in high poverty neighborhoods were observed for women with private health insurance.ConclusionsAmerica’s multi-tiered health insurance system mediates the quality of breast cancer care. The system is inequitable and unjust as it advantages the well insured and the well to do. Recent health care reforms ought to be enacted in ways that are consistent with their federal legislative intent, that high quality health care be truly available to all.

The Healthy Mind, Healthy Mobility Trial: A Novel Exercise Program For Older Adults

BACKGROUND More evidence is needed to conclude that a specific program of exercise and/or cognitive training warrants prescription for the prevention of cognitive decline. We examined the effect of a group-based standard exercise program for older adults, with and without dual-task training, on cognitive function in older adults without dementia. METHODS We conducted a proof-of-concept, single-blinded, 26-wk randomized controlled trial whereby participants recruited from preexisting exercise classes at the Canadian Centre for Activity and Aging in London, Ontario, were randomized to the intervention group (exercise + dual-task [EDT]) or the control group (exercise only [EO]). Each week (2 or 3 d · wk(-1)), both groups accumulated a minimum of 50 min of aerobic exercise (target 75 min) from standard group classes and completed 45 min of beginner-level square-stepping exercise. The EDT group was also required to answer cognitively challenging questions while doing beginner-level square-stepping exercise (i.e., dual-task training). The effect of interventions on standardized global cognitive function (GCF) scores at 26 wk was compared between the groups using the linear mixed effects model approach. RESULTS Participants (n = 44; 68% female; mean [SD] age: 73.5 [7.2] yr) had on average, objective evidence of cognitive impairment (Montreal Cognitive Assessment scores, mean [SD]: 24.9 [1.9]) but not dementia (Mini-Mental State Examination scores, mean [SD]: 28.8 [1.2]). After 26 wk, the EDT group showed greater improvement in GCF scores compared with the EO group (difference between groups in mean change [95% CI]: 0.20 SD [0.01-0.39], P = 0.04). CONCLUSIONS A 26-wk group-based exercise program combined with dual-task training improved GCF in community-dwelling older adults without dementia.

Comparison of Regression Models for the Analysis of Fall Risk Factors in Older Veterans

PURPOSE To compare the performance of eight regression models for analyzing risk of falling, focusing on the effect of physical inactivity in older veterans. METHODS This study uses data from a fall risk factor screening and modification trial in community-dwelling Canadian male veterans of World War II or the Korean War, with falls ascertained prospectively using calendars and physical activity (PA) measured at baseline with a single global question. The effect of PA on falling was assessed using eight different multivariable regression models, with three models treating falling as a non-recurrent event whereas the other five models regard falls as recurrent events. RESULTS Recurrent event models showed that male veterans who reported being less active than their peers were 1.42 (1.02-1.97) to 2.46 (1.18-5.14) times more likely to fall than those who reported being about as or more active than their peers (n = 270; mean age +/- SD = 81.1 +/- 4.0 years). None of the non-recurrent event models detected a statistically significant association between PA and falls. CONCLUSIONS Risk of falling may be better analyzed using regression models for recurrent events. These results have important implications for the collection and analysis of fall outcome data.

Multiplicative disadvantage of being an unmarried and inadequately insured woman living in poverty with colon cancer: historical cohort exploration in California

BackgroundMany Americans diagnosed with colon cancer do not receive indicated chemotherapy. Certain unmarried women may be particularly disadvantaged. A 3-way interaction of the multiplicative disadvantages of being an unmarried and inadequately insured woman living in poverty was explored.MethodsCalifornia registry data were analyzed for 2,319 women diagnosed with stage II to IV colon cancer between 1996 and 2000 and followed until 2014. Socioeconomic data from the 2000 census classified neighborhoods as high poverty (≥30% of households poor), middle (5–29%) or low poverty (<5% poor). Primary health insurance was private, Medicare, Medicaid or none. Comparisons of chemotherapy rates used standardized rate ratios (RR). We respectively used logistic and Cox regression models to assess chemotherapy and survival.ResultsA statistically significant 3-way marital status by health insurance by poverty interaction effect on chemotherapy receipt was observed. Chemotherapy rates did not differ between unmarried (39.0%) and married (39.7%) women who lived in lower poverty neighborhoods and were privately insured. But unmarried women (27.3%) were 26% less likely to receive chemotherapy than were married women (37.1%, RR = 0.74, 95% CI 0.58, 0.95) who lived in high poverty neighborhoods and were publicly insured or uninsured. When this interaction and the main effects of health insurance, poverty and chemotherapy were accounted for, survival did not differ by marital status.ConclusionsThe multiplicative barrier to colon cancer care that results from being inadequately insured and living in poverty is worse for unmarried than married women. Poverty is more prevalent among unmarried women and they have fewer assets so they are probably less able to absorb the indirect and direct, but uncovered, costs of colon cancer care. There seem to be structural inequities related to the institutions of marriage, work and health care that particularly disadvantage unmarried women that policy makers ought to be cognizant of as future reforms of the American health care system are considered.

Group-based exercise combined with dual-task training improves gait but not vascular health in active older adults without dementia

BACKGROUND Gait abnormalities and vascular disease risk factors are associated with cognitive impairment in aging. OBJECTIVE To determine the impact of group-based exercise and dual-task training on gait and vascular health, in active community-dwelling older adults without dementia. METHODS Participants [n=44, mean (SD) age: 73.5 (7.2) years, 68% female] were randomized to either intervention (exercise+dual-task; EDT) or control (exercise only; EO). Each week, for 26 weeks, both groups accumulated 50 or 75 min of aerobic exercise from group-based classes and 45 min of beginner-level square stepping exercise (SSE). Participants accumulating only 50 min of aerobic exercise were instructed to participate in an additional 25 min each week outside of class. The EDT group also answered cognitively challenging questions while performing SSE (i.e., dual-task training). The effect of the interventions on gait and vascular health was compared between groups using linear mixed effects models. RESULTS At 26 weeks, the EDT group demonstrated increased dual-task (DT) gait velocity [difference between groups in mean change from baseline (95% CI): 0.29 m/s (0.16-0.43), p<0.001], DT step length [5.72 cm (2.19-9.24), p =0.002], and carotid intima-media thickness [0.10mm (0.003-0.20), p=0.04], as well as reduced DT stride time variability [8.31 coefficient of variation percentage points (-12.92 to -3.70), p<0.001], when compared to the EO group. CONCLUSIONS Group-based exercise combined with dual-task training can improve DT gait characteristics in active older adults without dementia.

Disparities among Minority Women with Breast Cancer Living in Impoverished Areas of California

BACKGROUND Interaction effects of poverty and health care insurance coverage on overall survival rates of breast cancer among women of color and non-Hispanic white women were explored. METHODS We analyzed California registry data for 2,024 women of color (black, Hispanic, Asian, Pacific Islander, American Indian, or other ethnicity) and 4,276 non-Hispanic white women (Anglo-European ancestries and no Hispanic-Latin ethnic backgrounds) diagnosed with breast cancer between the years 1996 and 2000 who were then followed until 2011. The 2000 US census categorized rates of neighborhood poverty. Health care insurance coverage was either private, Medicare, Medicaid, or none. Cox regression was used to model rates of survival. RESULTS A 3-way interaction between ethnicity, health care insurance coverage, and poverty was observed. Women of color inadequately insured and living in poor or near-poor neighborhoods in California were the most disadvantaged. Women of color adequately insured and who lived in such neighborhoods in California were also disadvantaged. The incomes of such women of color were typically lower than the incomes of non-Hispanic white women. CONCLUSIONS Women of color with or without insurance coverage are disadvantaged in poor and near-poor neighborhoods of California. Such women may be less able to bare the indirect, direct, or uncovered costs of health care for breast cancer treatment.

Hockey Fans in Training: A Pilot Pragmatic Randomized Controlled Trial

Introduction Hockey Fans in Training (Hockey FIT) is a gender-sensitized weight loss and healthy lifestyle program. We investigated 1) feasibility of recruiting and retaining overweight and obese men into a pilot pragmatic randomized controlled trial and 2) potential for Hockey FIT to lead to weight loss and improvements in other outcomes at 12 wk and 12 months. Methods Male fans of two ice hockey teams (35–65 yr; body mass index ≥28 kg·m−2) located in Ontario (Canada) were randomized to intervention (Hockey FIT) or comparator (wait-list control). Hockey FIT includes a 12-wk active phase (weekly, coach-led group meetings including provision of dietary information, practice of behavior change techniques, and safe exercise sessions plus incremental pedometer walking) and a 40-wk minimally supported phase (smartphone app for sustaining physical activity, private online social network, standardized e-mails, booster session/reunion). Measurement at baseline and 12 wk (both groups) and 12 months (intervention group only) included clinical outcomes (e.g., weight) and self-reported physical activity, diet, and self-rated health. Results Eighty men were recruited in 4 wk; trial retention was >80% at 12 wk and >75% at 12 months. At 12 wk, the intervention group lost 3.6 kg (95% confidence interval, −5.26 to −1.90 kg) more than the comparator group (P < 0.001) and maintained this weight loss to 12 months. The intervention group also demonstrated greater improvements in other clinical measures, physical activity, diet, and self-rated health at 12 wk; most sustained to 12 months. Conclusions Results suggest feasible recruitment/retention of overweight and obese men in the Hockey FIT program. Results provide evidence for the potential effectiveness of Hockey FIT for weight loss and improved health in at-risk men and, thus, evidence to proceed with a definitive trial.