Shaping ability of XP-endo Shaper and ProTaper Next in long oval-shaped canals: a micro-computed tomography study.

AIM: To evaluate the shaping ability of the single-file XP-endo Shaper system (XP-S; FKG Dentaire, La Chaux-de-Fonds, Switzerland) employing a different working time and of the multiple-file ProTaper Next system (Dentsply Sirona, Ballaigues, Switzerland) using micro-computed tomography (micro-CT) technology. METHODOLOGY: Twenty long oval-shaped canals in mandibular incisors were matched anatomically and scanned by micro-CT (Skyscan 1172; Bruker micro-CT, Kontich, Belgium). The canals were divided into two groups (n = 10) according to the canal preparation protocol: XP-endo Shaper (XP-S) with an extra 45 s of instrumentation and ProTaper Next (PTN X4). The images recorded before and after preparation were evaluated for morphometric measures of volume, surface area, structure model index and untouched walls. The data were compared statistically (Student's t-test for homogenous variances and Mann-Whitney test) between the two groups (XP-S and PTN X4) at α = 5%. RESULTS: Root canal preparation significantly increased all parameters (volume, surface area, structure model index and untouched walls) tested in each group (P < 0.05). There was no significant difference (P > 0.05) in the percentage increase of volume (107.50%-93.13%), surface area (27.74%-29.68%) or untouched canal wall (13.08%-11.74%) between XP-S and PTN X4, respectively. CONCLUSIONS: The XP-endo Shaper system (single-file) with an extra 45 s of instrumentation and the ProTaper Next system (multiple files) had a similar root canal shaping ability. Neither technique was able to fully prepare the long oval-shaped canals of mandibular incisors.

Generating Rasch-based activity of daily living measures from the Spinal Cord Injury Longitudinal Aging Study.

STUDY DESIGN: Retrospective Longitudinal Study. OBJECTIVES: (1) To determine whether the Spinal Cord Injury Activities of Daily Living (SCI_ADL) measure shows adequate item-level and precision psychometrics; (2) to investigate whether the SCI_ADL measure effectively detects ADL changes across time; (3) to describe self-care task(s) participants can and cannot do across time. SETTING: Two Midwestern hospitals and 1 Southeastern specialty hospital in 1993. METHODS: All participants were adults with traumatic SCI of at least 1-year duration at enrollment. We used 20-year (1993-2013) retrospective longitudinal data and categorized participants into three injury levels: C1-C4 (cervical; n=50), C5-C8 (n=126) and T1-S5 (thoracic, lumbar and sacral; n=168). We first examined psychometrics of the SCI_ADL with factor and Rasch analyses; then we investigated longitudinal change of SCI_ADL scores at three time points over 20 years (1993, 2003 and 2013) using generalized linear mixed modeling and post hoc analyses. RESULTS: The SCI_ADL measure demonstrated unidimensionality, person strata of 2.9, high Cronbach's α (0.93) and fair person reliability (0.76). T1-S5 had the highest measures, following C5-C8 and C1-C4 at three time points (P<0.05). The C1-C4 and T1-S5 groups showed significant decreases from 2003 to 2013; however, none of the three groups showed significant differences from 1993 to 2003 (P<0.05). CONCLUSIONS: The SCI_ADL measure could detect longitudinal ADL changes of the population with SCI across time. The C1-C4 group decreased the most in ADLs, indicating higher need of long-term services and rehabilitation.

Rasch measurement properties of the Pain Medication Questionnaire in persons with spinal cord injury.

STUDY DESIGN: Secondary analysis of cross-sectional population-based self-report data. OBJECTIVE: To determine how well the Pain Medication Questionnaire (PMQ) measures risk of pain medication misuse and its precision in separating individuals with spinal cord injury (SCI) into meaningful classification categories. SETTING: Academic medical center in Southeastern United States. METHODS: Data were collected from a population-based registry of SCI (n=971). Eligible participants included adults with traumatic SCI with residual effects who were at least 1 year post injury and 18 years of age and who had PMQ data in which they reported active use of pain medication at the time of the study (n=745). RESULTS: Most items (23/26) of the PMQ contributed to a single unidimensional construct. Rasch analysis results revealed that the rating scale, majority of persons (>93%), and majority of items (20/23) fit the Rasch measurement model. The PMQ demonstrated adequate reliability (person reliability =0.67) and separated persons into two strata-those likely to misuse pain medication and those with low liklihood of misusing pain medication. CONCLUSIONS: Findings offer a deeper understanding of the measurement properties of the PMQ as a precursor for widespread population-based studies to elucidate the incidence of pain medication misuse in persons with SCI. Results also have important research and clinical implications for commonly used PMQ total score cut-offs, which may misclassify an individual's risk of pain medication misuse.

Ontogeny of electrical activity of main olfactory bulb in freely-moving normal and malnourished rats.

Electroencephalographic activity (EEG) was recorded from the main olfactory bulb (MOB) in freely-moving, normally-nourished, (NP, normal-protein diet) and malnourished (LP, low-protein diet) rats from 4 days of age through adulthood. MOB EEG was analyzed for dominant frequency components using power spectral techniques. For NP rats, a single dominant frequency component (induced wave) was present in the MOB EEG at 4-6 days of age. From 10 days of age through adulthood, the MOB EEG contained two dominant frequency components (induced and intrinsic waves). Both the induced wave and intrinsic waves increased in center-frequency to reach maturity at approximately 30 days of age. Rats reared on low-protein diets (8% casein, prenatal and postnatal) displayed relatively permanent retardation in the development of induced wave center-frequencies and a delay in the development of the intrinsic wave center-frequencies. These results closely parallel the morphological development of the MOB in normally-nourished and malnourished rats.

Modulation of lateral hypothalamic activity by olfactory bulb and sciatic stimulation.

Lateral hypothalamic area (LHA) single unit activity (extracellular) was studied in response to electrical stimulation of the olfactory bulb (OB) or sciatic nerve in adult albino rats (n = 39) anesthetized with dialurethane. Olfactory stimulation resulted in a greater proportion of LHA units showing inhibitory rather than excitatory responses, while sciatic nerve stimulation resulted in similar proportions of units showing inhibitory and excitatory responses. Of the 76 LHA units tested with both OB and sciatic nerve stimulation, 36% responded to both stimulation sites, 18% responded only to OB stimulation, 26% responded only to sciatic nerve stimulation, and 20% were unresponsive to either stimulation. The locations of responsive units were diffuse throughout the LHA sampled. The response characteristics of LHA neurons to external sensory stimulation are consistent with the anatomy and putative integrative functions of this brain region.

Work evaluations: critique of the state of the art of functional assessment of work.

The area of work evaluation is fertile ground for future research and development by occupational therapists. Current evaluations of work range from standardized work evaluations associated with vocational rehabilitation to highly technical physical capacity and work capacity instrumentation and equipment often associated with sports medicine. In addition, methods used to identify pain and abnormal illness behavior add the psychosocial component of work evaluation. The limitations of most of the traditional approaches to work evaluations are their lack of focus on the actual work environments and on the meaning of work to persons. Occupational therapy can play an important and unique role in linking work evaluations to psychosocial and environmental variables and in formulating comprehensive theoretical models of work that should improve and refine present work evaluations.

Using the assessment of motor and process skills to compare occupational performance between clinic and home settings.

OBJECTIVES: The study described in this article examined the effect of home versus clinic settings on the instrumental activities of daily living (IADL) performance of older adults. METHOD: Twenty older adults living in the community were evaluated in their homes and in an occupational therapy clinic with the Assessment of Motor and Process Skills (AMPS). The motor and process ability measures were compared between the two settings with many-faceted Rasch analysis. RESULTS: The subjects' motor ability measures tended to remain stable from clinic to home settings. The process ability measures tended not to remain stable from clinic to home settings, because 10 of the 20 subjects performed significantly better in their homes. CONCLUSION: These findings support the idea that process skill abilities are affected by the environment to a greater degree than are motor skills abilities and that for persons living in the community, the familiar home environment tends to support IADL performance. If an occupational therapist wants to know how a person performs IADLs, the therapist should evaluate that person's performance in the environment in which the client will be functioning.

The use of Rasch analysis to produce scale-free measurement of functional ability.

Innovative applications of Rasch analysis can lead to solutions for traditional measurement problems and can produce new assessment applications in occupational therapy and health care practice. First, Rasch analysis is a mechanism that translates scores across similar functional ability assessments, thus enabling the comparison of functional ability outcomes measured by different instruments. This will allow for the meaningful tracking of functional ability outcomes across the continuum of care. Second, once the item-difficulty order of an instrument or item bank is established by Rasch analysis, computerized adaptive testing can be used to target items to the patient's ability level, reducing assessment length by as much as one half. More importantly, Rasch analysis can provide the foundation for "equiprecise" measurement or the potential to have precise measurement across all levels of functional ability. The use of Rasch analysis to create scale-free measurement of functional ability demonstrates how this methodlogy can be used in practical applications of clinical and outcome assessment.

Cross-cultural assessment of process skills.

A standardized activities of daily living evaluation that has acceptable psychometric qualities, can relate discrete component skills to functional performance, includes culture-relevant test items, is standardized on culture-specific samples, and is free of cultural bias is needed to evaluate diverse cultural populations. The Assessment of Motor and Process Skills (AMPS) (Fisher, 1990a) offers a unique solution. The AMPS consists of 35 motor and process skill items assumed to represent two universal taxonomies that are free of cultural bias. The study described in this paper focused on the 20 process skill items of the AMPS process skills scale. To test the hypothesis that the AMPS process skills scale is suitable for cross-cultural applications, a translation of the AMPS was calibrated on a group of 20 Taiwanese subjects. The validity and reliability of the AMPS process skills scale were examined when applied to this sample. Examination of reliability included the extent to which rater scoring remained stable over time. The results revealed that the AMPS process skills scale has high intrarater reliability and is valid when applied to young nondisabled Taiwanese subjects. The results suggested that the AMPS could be applied to Taiwanese samples. However, further investigation is needed to determine whether Taiwanese activities can be calibrated onto the same scale as North American activities to make a single cross-cultural AMPS.

Developing meaningful Fear of Falling Measures for community dwelling elderly.

OBJECTIVE: The objective of this study is to demonstrate how a Rasch analytic approach can be used to create fear of falling measures that remain connected to the meaningful descriptions provided by the instrument items. DESIGN: The University of Illinois at Chicago Fear of Falling Measure was developed using focus groups and consists of 19 common activities designed to represent an increasing level of concern about falling among older adults. RESULTS: Rasch analysis of responses from 106 community dwelling elderly revealed that the two middle rating scale categories (a little worried and moderately worried) were not being used in the expected fashion. After modification of the rating scale, Rasch analysis showed that the three items causing the least worry (get dressed, get on/off toilet, and get in/out of bed) were statistically erratic. CONCLUSION: Final analysis demonstrated that the remaining 16 items represented a unidimensional construct that, in general, supported the original expected item difficulty hierarchy. Because person and item measures were calibrated on the same linear scale person measures are translatable to item descriptions. This connection provides meaning to the numeric values obtained from the instrument and provides a basis for setting clinically relevant criteria for interventions.

Prior psychiatric problems in rehabilitation clients with work-related injuries.

Psychiatric histories were obtained in 56 patients beginning rehabilitation following a work-related injury in order to establish the temporal relationship between the onset of psychiatric problems and the date of the work injury. The presence of major depression and alcohol abuse was determined using structured, directed interviews and the criteria set forth in the Diagnostic and Statistical Manual of Mental Disorders. A history of either alcohol abuse or depression was found in 36 (64.3%) of the 56 subjects. Of these 36 subjects, 32 (88.9%) reported a history of psychiatric problems that antedated the work injury. These data suggest that, in injured workers, the conceptualization of psychiatric problems solely as reactive illnesses in otherwise psychiatrically healthy persons is often inaccurate. Furthermore, these data suggest the hypothesis that the presence of clinical depression or alcohol abuse may increase the risks of a work-related injury.

Prediction of return to work by rehabilitation professionals.

Rehabilitation therapists made predictions of return to work for 57 patients evaluated prior to beginning a work-hardening program. These predictions, along with 14 specific demographic, injury, and physical function measures were entered into a stepwise discriminant analysis to develop a predictive model for return to work. Therapists correctly predicted the eventual return to work for 47 (73.7%) of the 57 subjects. Therapist prediction was the most powerful variable in the model, explaining 29% of the variance (p≤.0001). Only two other variables, self-report of pain severity and injury type, contributed significantly to the prediction model, accounting respectively for 12% and 9% of the variance (p's<.05). These data highlight the predictive acuity of rehabilitation therapists and suggest that the process involved in formulating clinical predictions merits further study. The findings also suggest that weighing information such as self-report of pain severity and injury type might further enhance the practitioner's ability to predict return to work.

Maintaining instrument quality while reducing items: application of Rasch analysis to a self-report of visual function.

While efficiency has been of concern in the measurement of health care outcomes, little attention has been devoted to methods that achieve efficient, shortened instruments that have good psychometric properties. The purpose of this study was to show how Rasch analysis could be used to reduce the number of items in an instrument while maintaining credible psychometric properties. This approach was applied to the Visual Function-14 (VF-14), a self-report of 14 vision-dependent activities, designed to measure the need for and outcomes of cataract surgery. An instrument which contained the VF-14 plus an additional 10 items that were developed for the study (VF-24) was administered to sixty-one patients (73.7+/-9.5 years) about to undergo extracapsular cataract removal at one of two surgical centers. Rasch analysis (BIGSTEPS) of the VF-14 showed a number of limitations to the original instrument, including: 1) unequal use of the five rating categories, 2) ceiling effect, 3) several other gaps where patient abilities did not match with item difficulties, and 4) sets of items that appeared redundant, (i.e., having the same calibration level). To resolve the first three of these problems, the rating scale was converted to a three-point scale and BIGSTEPS was run with all 24 items. (10 additional items added to the VF-14 designed to "fill in" the gaps). The conversion to a three-point scale and the increase in items resulted in some improvement in the matching of item difficulty to patient ability, as evidenced by a slight decrease in gaps. The addition of items resulted in improvements in person separation (2.55 to 2.99) and Cronbach's alpha (.83 to .91) but did not substantially reduce the ceiling effect and furthermore resulted in an increase in item redundancy. The final practical improvement undertaken was to reduce the number of items while attempting to maintain the psychometric qualities of the instrument as a whole. Three criteria were used in deciding to remove items: 1) high mean square, 2) low mean square and 3) items having similar calibrations. In addition, if an analysis showed that the removal of an item substantially decrease person separation, that item was retained for further analyses. Relative to the original VF-14, the resulting VF-10 showed less redundancy of items while person separation (2.20) and Cronbach's alpha (.89) remained relatively intact. The study demonstrates that Rasch analysis, while effective in elucidating the metrics of an original instrument, can also be useful in designing modifications of instruments that are both efficient and psychometrically sound.

Functional scale discrimination at admission and discharge: Rasch analysis of the Level of Rehabilitation Scale-III.

OBJECTIVE: To determine the construct validity of the Level of Rehabilitation Scale-III (LORS-III) with a special focus on this instrument's capability to discriminate rehabilitation inpatient activities of daily living (ADL)/mobility and communication/cognition ability at admission and discharge. DESIGN: Rasch analysis of existing data sets in the LORS-III American Data System (LADS). PATIENTS: Existing admission and discharge data from 3056 rehabilitation inpatients (musculoskeletal injury, cerebrovascular accident, multiple injuries/diseases, brain injury, neuromuscular disorder, and spinal cord injury) entered into LADS between April 1992 and January 1993. MAIN OUTCOME MEASURE: LORS-III consists of 17 measurement areas representing abilities in ADL, mobility, communication, cognition, and memory. Fourteen of the measurement areas are concurrently scored by a nurse and a specified rehabilitation therapist, resulting in a total of 31 items. RESULTS: Consistent with findings reported for other functional status measures, the analysis indicated that the LORS-III consists of two unidimensional scales, an ADL/mobility scale, and a communication/cognition scale. Although all scales fit the Rasch measurement model, the ADL/mobility scale used at admission was most appropriately targeted to the ability level of the sample. At discharge, the ADL scale was generally too easy because the ability level of the sample moved upward towards functional independence. The communication/cognition scale at both admission and discharge showed a similar "ceiling" effect. CONCLUSIONS: These findings indicate the importance of determining the measurement qualities of functional status measures for both admission and discharge ratings. Analyses, such as Rasch, can provide a logical direction for instrument refinement.