Of the 1002 eligible members, 754 (75.2%) agreed to participate in the study. Only 4.6% of the 2,753 health plan members who were alive and could be contacted refused to complete the screening telephone interview, and only 3.6% of otherwise eligible persons were excluded because of significant cognitive impairment and no available proxy. 15Įligibility was determined during a screening telephone interview and was confirmed during an in-home assessment. 16 – 18 Health plan members were excluded on the basis of three criteria: diagnosis of a terminal illness with a life expectancy less than twelve months, plans to move out of the New Haven area during the next 12 months, and significant cognitive impairment with no available proxy. 15 Slow gait speed has repeatedly been shown to be the single best predictor of ADL disability. Persons scoring > 10 seconds on the rapid gait test were oversampled to ensure a sufficient number of participants at increased risk for ADL disability, as described previously. Eligible participants were community-living, English-speaking, and nondisabled in four key activities of daily living (ADL) – bathing, walking, dressing, and transferring. 15 Potential participants were identified from a computerized list of 3,157 age-eligible members of a large health plan in greater New Haven, Connecticut. The assembly of the cohort, which took place between March 1998 and October 1999, has been described elsewhere. Participants were drawn from an ongoing longitudinal study of 754 initially nondisabled, community-living persons, aged ≥ 70 years. 14 Such findings would support the use of PEF as a risk assessment tool for outcomes that are relevant to independent living and longevity. In the present study, we set out to determine whether PEF, expressed as an SR-percentile, is associated with subsequent disability and death in a cohort of initially nondisabled, community-living older persons. 2, 5, 8 Furthermore, despite the preeminence of functional outcomes in older persons, prior studies of PEF have not evaluated the association of PEF and subsequent disability. Importantly, prior studies in older persons have reported PEF either simply as a measured value, without comparison to a predicted mean 3, 4, 6, 7 or as a residual that is neither standardized nor based on a correctly derived predicted mean, i.e., weight was used as a predictor variable. 1, 9, 14 In this equation, the numerator is referred to as the residual, while the denominator is a constant that quantifies the scatter of measured values about the predicted mean (i.e., the spread of the reference data) a percentile based on the SR is then computed. 1, 9 – 11 In older persons, such a comparison is expressed effectively as a standardized residual (SR), calculated as. 12, 13 Thus, when reporting PEF, a comparison needs to be made between what is measured and a reference value, namely the predicted mean of a population of normal subjects having the same anthropometric variables. 1, 9 – 11 Weight is not a predictor variable, as obesity does not lead to a larger lung, although it may reduce pulmonary function. In a normal reference population, PEF is influenced by the anthropometric variables of height, age, and gender, and, when appropriate, ethnicity. 2, 4, 5, 8 As discussed below, however, these findings lack generalizability because PEF has not been reported in a manner consistent with published guidelines. 6 – 8 Fourth, in many cases, these associations persist even after accounting for smoking status. 2 – 5 Third, a decreased PEF in older persons is longitudinally associated with cognitive decline, institutionalization, and death. 1 Second, in older persons, PEF is cross-sectionally associated with health status and physical and cognitive function. First, it is a simple, inexpensive, and readily available measure of pulmonary function. Peak expiratory flow (PEF), defined as the maximum flow achieved during expiration delivered with maximal force starting from maximal lung inflation, 1 has several attributes that warrant its consideration as a risk assessment tool in older persons.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |