Biomedical subjects

Louise J White

Publications and source records attributed to Louise J White.

3 recordsLinked to original sources

PubMed2004

Using compensations to assess physical performance for ambulatory outpatients.

OBJECTIVE: To construct a physical performance scale for community-dwelling ambulatory outpatients that is linear, includes high functioning tasks, and uses common compensations to assess difficulty levels. DESIGN: Calibrated subject performances on 19 tasks were rated by an examiner, timed, and had compensations recorded. SETTING: Ambulatory outpatient physical therapy (PT) department of a tertiary care center. PARTICIPANTS: Convenience sample of 50 community-dwelling patients with difficulties in mobility referred for PT. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The Community Ambulatory Physical Performance Scale (CAPPS) constructed by using Rasch analysis, the Lower Extremity Functional Scale (LEFS), and the six-minute walk test (6MWT). RESULTS: The CAPPS showed construct validity after removal of 3 items. Two additional items were removed for improved clinical utility. The person reliability was .89 and item reliability was .98. Subjects' performance on the CAPPS correlated with the 6MWT (r=.79; 95% confidence interval [CI], .65-.87) and with the LEFS (r=.62; 95% CI, .40-.78). CONCLUSIONS: The CAPPS showed good psychometric properties and has utility for assessments of higher-level physical functioning. This standardized approach to performance testing for ambulatory outpatients appears to be a promising method for articulating the compensations persons use to accomplish common tasks. Use of compensatory strategies to assess difficulties in physical performance may assist in delineating interventions directed toward improving task performance.

Activities of Daily Living↗

PubMed2003

Factors affecting the duration effect in pitch perception for unresolved complex tones.

Previous research has shown that fundamental frequency (F0) discrimination thresholds for complex tones containing unresolved harmonics decrease as the duration of the tone increases [White and Plack, J. Acoust. Soc. Am. 103, 2051-2063 (1998)]. In this paper F0 discrimination was measured as a function of duration for complexes with F0s of 62.5, 125, and 250 Hz, bandpass filtered into two spectral regions (2750-3750 and 5500-7500 Hz). The harmonics were summed either in sine phase (SINE) or with alternating sine-cosine phase (ALT), which affects the envelope of the waveform and the pitch of the complex. Tone duration was 20, 40, 80, and 160 ms. The improvement in F0 discrimination with duration increased with decreasing F0. When harmonics where spectrally filtered between 2750 and 3750 Hz, for complexes with an F0 of 62.5 Hz, F0 discrimination thresholds decreased from approximately 30% for a 20-ms tone to approximately 3% for a 160-ms tone. For complexes with an F0 of 250 Hz, thresholds decreased from 3% for a 20-ms tone to 1% for a 160-ms tone: a lower envelope repetition rate led to a larger change in performance with increasing duration. The phase manipulation also affected the size of the duration effect, in that the effect was less for an ALT complex compared to a SINE complex with the same F0, consistent with the change in envelope repetition rate. Overall, the results suggest that for unresolved complex tones it is primarily envelope repetition rate, not spectral region, that determines both the F0 discrimination threshold and the size of the duration effect.

Adult↗

PubMed2002

The use of Rasch measurement to improve the Oswestry classification scheme.

OBJECTIVES: To use Rasch measurement to assess and modify the original classification categories of the Oswestry Low Back Pain Disability Questionnaire (Oswestry), to examine the hypothesis that the items from the Oswestry form a unidimensional construct and a hierarchical representation of low back pain (LBP) disability, and to compare ordinal Likert resultant scores to interval Rasch scaled scores with disability categories serving as a framework. DESIGN: Rasch analysis model. Existing Oswestry admission data generated by FOTO were analyzed. SETTING: Statistical analysis of sample database. PARTICIPANTS: A sample of 942 patients with LBP referred for physical therapy between 1993 and 1994. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Construct validity; disability categories (as assessed by Likert and Rasch models); and fit statistics (infit, outfit as mean squares). RESULTS: All items from the Oswestry except the pain item fit the Rasch model. Construct validity of the scale using the Rasch model required the structure of the rating scale to be modified from 6 response levels to 4. A hierarchical representation of LBP disability was supported. A comparison of the disability categories based on Likert and Rasch scaling revealed them to be nonequivalent. The new scaling changed the disability categories for 44% of patients. CONCLUSION: Rasch analysis produced disability categories in the Oswestry that are linear and, therefore, useful for quantitatively assessing self-reported disability levels.

Adolescent↗