Validation of the Impact Index: can we measure disease effects on quality of life in patients with hip and knee osteoarthritis?

PURPOSE: To validate the Impact Index, a short, publicly available scale that measures the extent to which a respondent's health problem adversely impacts their quality of life. METHODS: Secondary analysis of patients with hip or knee osteoarthritis surveyed after visiting a surgeon at baseline (N = 322) and about 6 months after the visit (N = 283). Patients responded to the Impact Index and previously validated questionnaires about overall health, pain, and function. The Impact Index includes four questions that ask how much the respondent is bothered, worried, limited, or in pain due to their health condition over the past 30 days. Total scores range from 0 to 12; higher scores indicate more deleterious impact. RESULTS: Patients were mostly female (55%), majority white (95%), had an average age of 65 (SD = 9), and most had surgery (64%). The baseline Impact Index score was 9.48 (SD = 2.63); at follow up 4.75 (SD = 3.54). Impact Index was related to overall health at baseline (r = - 0.49). For knee patients at baseline, Impact Index was negatively related to their knee symptoms (r = - 0.49) and knee pain (r = - 0.67). For hip patients at baseline, Impact Index was negatively related to the Harris Hip score (r = - 0.62). Scale directions varied; however, the signs of all correlations were as hypothesized. The Impact Index was predictive of surgical choice (p < .001, OR = 1.45), however, overall health (p = .88) and comorbidity (p = .24) measures were not. Reliability was acceptable (α = 0.85). Responsiveness statistics suggested overall health, pain, function, and Impact Index measures reflected improvement patients experienced from surgery. The Impact Index had the largest effect sizes (> - 3.4) and Guyatt Responsiveness Statistics (> - 2.3). CONCLUSIONS: The Impact Index demonstrated strong evidence of validity, reliability, and responsiveness in hip or knee osteoarthritis patients.

Nutrient intake of physically fit and unfit men and women.

OBJECTIVE: Participation in physical activity and following a diet low in fat, saturated fat, and cholesterol and high in fiber are important in the prevention and treatment of cardiovascular disease and other health problems. Despite the importance of both behaviors, little is known about the interactive role of diet and physical activity. The association between physical activity and diet has been studied, but data on the association between cardiorespiratory fitness (CRF), which is an objective measure of habitual physical activity, and diet are lacking in adults. This report examines nutrient intakes of men and women across low, moderate, and high fitness categories and compares the intakes to national dietary recommendations. It is the first step in examining the relationship between diet, CRF, and morbidity and mortality endpoints in the Aerobics Center Longitudinal Study (ACLS). METHODS: Between 1987 and 1995, 7959 men and 2453 women participating in the ACLS provided 3-d diet records and completed a preventive medical examination. CRF was measured using a maximal exercise test, anthropometric and other clinical variables were measured following a standardized protocol, and lifestyle factors were assessed with a medical history questionnaire. RESULTS: After adjusting for potential confounders, there was a significantly lower percent of energy from fat and saturated fat across low, moderate, and high CRF categories. With additional adjustment for total energy intake, there was a significantly higher dietary fiber intake and a significantly lower cholesterol intake across CRF categories. The percentage of men and women meeting national dietary recommendations was higher at higher CRF levels. CONCLUSIONS: Men and women with higher fitness levels consumed diets that more closely approached national dietary recommendations than their lower fit peers.

Comparison of a dietary record using reported portion size versus standard portion size for assessing nutrient intake.

OBJECTIVE: Because the percentage of missing portion sizes was large in the Aerobics Center Longitudinal Study (ACLS), careful consideration of the accuracy of standard portion sizes was necessary. The purpose of the present study was to investigate the consequences of using standard portion sizes instead of reported portion sizes on subjects' nutrient intake. METHODS: In 2307 men and 411 women, nutrient intake calculated from a 3-day dietary record using reported portion sizes was compared with nutrient intake calculated from the same record in which standard portion sizes were substituted for reported portion sizes. RESULTS: The standard portion sizes provided significantly lower estimates (>/= 20%) of energy and nutrient intakes than the reported portion sizes. Spearman correlation coefficients obtained by the two methods were high, ranging from 0.67 to 0.93. Furthermore, the agreement between both methods was fairly good. Thus, in the ACLS the use of standard portion sizes rather than reported portion sizes did not appear to be suitable to assess the absolute intake at the group level, but appeared to lead to a good ranking of individuals according to nutrient intake. These results were confirmed by the Continuing Survey of Food Intake by Individuals (CSFII), in which the assessment of the portion size was optimal. When the standard portion sizes were adjusted using the correction factor, the ability of the standard portion sizes to assess the absolute nutrient intake at the group level was considerably improved. CONCLUSIONS: This study suggests that the adjusted standard portion sizes may be able to replace missing portion sizes in the ACLS database.

Effects of physical inactivity and obesity on morbidity and mortality: current evidence and research issues.

PURPOSE: The purpose of this review was to address three specific questions. 1) Do higher levels of physical activity attenuate the increased health risk normally observed in overweight or obese individuals? 2) Do obese but active individuals actually have a lower morbidity and mortality risk than normal weight persons who are sedentary? 3) Which is a more important predictor of mortality, overweight or inactivity? METHODS: We initially identified more than 700 articles that included information on the exposure variables of body habitus (body mass index, body composition, or body fat pattern) and physical activity habits, and on outcomes such as morbidity or mortality. To be included in the review, we required that an article include an analysis of one of our outcomes by strata of the two exposure variables. We excluded review articles and reports of cross-sectional analyses. We used an evidence-based approach to evaluate the quality of the published data. RESULTS: We summarized results from 24 articles that met all inclusion criteria. Data were available for the outcomes of all-cause mortality, cardiovascular disease mortality, coronary heart disease (CHD), hypertension, type 2 diabetes mellitus, and cancer. Summary results for all outcomes except cancer were generally consistent in showing that active or fit women and men appeared to be protected against the hazards of overweight or obesity. This apparent protective effect was often stronger in obese individuals than in those of normal weight or who were overweight. There were too few data on cancer to permit any conclusions. CONCLUSIONS: There are no randomized clinical trials on the topics addressed in this review. All studies reviewed were prospective observational studies, so all conclusions are based on Evidence Category, C. The conclusions for the three questions addressed in the review are: 1) regular physical activity clearly attenuates many of the health risks associated with overweight or obesity; 2) physical activity appears to not only attenuate the health risks of overweight and obesity, but active obese individuals actually have lower morbidity and mortality than normal weight individuals who are sedentary, and 3) inactivity and low cardiorespiratory fitness are as important as overweight and obesity as mortality predictors. Research needs include extending current observations to more diverse populations, including more studies in women, the elderly, and minority groups, assessment methods need to be improved, and randomized clinical trials addressing the questions discussed in this review should be undertaken. Owing to size, complexity, and cost, these trials will need to be designed with valid noninvasive measures of subclinical disease processes as outcomes.