Principal Components Analysis Of Items Research Articles

Predictors of pharmacists’ likelihood to query prescription drug monitoring program databases

BackgroundLow rates of enrollment and querying of the prescription drug monitoring programs (PDMPs) may be detrimental to the effectiveness of controlling prescription drug misuse. A number of individual-level, organizational, and regulatory factors may affect a community pharmacist’s likelihood to query their statewide PDMP. ObjectiveTo identify predictors of pharmacists’ likelihood to query the PDMP. MethodsA self-administered survey was used to collect data from community pharmacists from a national panel. Measures were identified from previous literature assessing provider likelihood to query PDMPs. A principal components analysis of items pertaining to pharmacists’ likelihood to query PDMPs was conducted as a data reduction technique to identify underlying dimensions. Multivariable linear regression was conducted to examine relationships between 5 predictor variables (state regulations, practice setting, workload, perceived barriers, and attitude) and the identified components. ResultsA total of 148 completed survey responses were included for final analysis. The pharmacists’-likelihood-to-query scale comprised 2 components accounting for 71% of the total variance. The 2 components were labeled as higher-risk situations and lower-risk situations. Multivariable linear regression indicated that pharmacists’ likelihood to query the PDMP for the higher-risk situations was not statistically significant for any predictor variables. For the lower-risk situations, pharmacists who had a more positive attitude toward the effectiveness of the PDMP were more likely to query it in these situations (unstandardized coefficient = 0.167; P = 0.018). ConclusionThe factors affecting pharmacists’ likelihood to query the PDMP may differ depending on the situations faced by the pharmacist. On the basis of the study results, it seems that pharmacists are currently aware of the importance of checking the PDMP and regularly query it. Overall, the respondent pharmacists had a positive attitude toward the effectiveness of the PDMP, which seems to have a role in their likelihood to query it in lower-risk situations.

Nurses’ perception of the use of computerised information systems in practice: questionnaire development

To develop and validate a questionnaire to explore the perceptions of nurses about the implementation of a computerised information system in clinical practice. A growing interest in understanding nurses' experience of developing and implementing clinically relevant Information Technology systems and the lack of measurement tools in this area, justifies further research into the development of instruments to provide an insight into nurses' experience. Survey and questionnaire development. An initial draft of the questionnaire was developed based on the literature and expert opinion. The questionnaire was piloted by ten nurses to check face validity, reliability and test-retest reliability. A revised version of the questionnaire was distributed to nurses working in the in-patient area of a university hospital in Spain (n = 227). Principal components analysis with oblique rotation was carried out to test theoretically developed underlying dimensions and to test construct validity. Cronbach's alpha coefficient was used to determine internal consistency. Cronbach's alpha for all the items included in the different scales was 0.88 in the pilot questionnaire and test-retest reliability was adequate. Principal components analysis of items related to mechanisms produced a three-component structure ('IT support', 'usability' and 'information characteristics'). The three factors explained 48.6% of the total variance and Cronbach's alpha ranged from 0.66-0.79. Principal components analysis of items related to outcomes produced a three factor solution ('impact on patient care', 'impact on communication' and 'image profile'). The factors explained 65.9% of the total variance and Cronbach's alpha ranged from 0.64-0.85. The study provides a detailed description and justification of an instrument development process. The instrument is valid and reliable for the setting where it has been used. The instrument could provide insight into nurses' experience of IT implementation that will guide further development of systems to enhance clinical practice.

Modification of the Perinatal PTSD Questionnaire to enhance clinical utility

To enhance the clinical utility of the Perinatal Post-Traumatic Stress Disorder (PTSD) Questionnaire (PPQ), the current study sought to refine the measure by changing the item response options from dichotomous choices to a likert scale format. Using a convergent/divergent validity design and two data sources (traditional survey and World Wide Web), 58 high-risk and 86 low-risk mothers answered four questionnaires. Principal components analysis of items on the modified PPQ revealed three components conceptually similar to the diagnostic criterion associated with PTSD. In addition, convergent and divergent validity of the modified measure was supported. The clinical utility of the modified PPQ was established with a strong positive likelihood ratio. The modified PPQ is a useful clinical tool for identifying mothers experiencing significant emotional distress during the postnatal period so they may be referred for mental health services.

The clinician-administered rating scale for mania (CARS-M): Development, reliability, and validity

There are currently seven rating scales available to assess manic symptomatology. All, however, have some limitations that could restrict their clinical and research utility. To resolve these deficiencies the Clinician-Administered Rating Scale for Mania (CARS-M) was developed and normed on 96 patients with mixed diagnoses during baseline and following treatment. Interrater reliability was established across multiple raters viewing 14 videotaped interviews and comparing agreement among individual items and total scores. Test-retest reliability was assessed on 36 patients twice during baseline. The mean intraclass correlation coefficient among five raters across items for each of the 14 patients was 0.81, and for total scores 0.93. Principal components analysis of items revealed two factors: mania, and psychosis. Test-retest reliability was significant for both factors (range = 0.78 to 0.95). Internal validity, comparing each item with its respective total factor score, revealed significant correlations for all items. Correlation of CARS-M total scores with mania rating scale (MRS) total scores was 0.94. Results indicate the CARS-M is both a reliable and valid measure of the severity of manic symptomotology, which incorporates a number of methodological improvements leading to greater precision and clinical utility.

Positive and negative symptoms in the psychoses: Principal components analysis of items from the scale for the assessment of positive symptoms and the scale for the assessment of negative symptoms

The present study investigated the factor structure of the items contained in Andreasen's scales for the assessment of positive and negative symptoms (SAPS and SANS) by use of a series of principal components analyses (PCAs) with oblique rotations of the axes. It was found that the structure could be summarized by three major components labeled negative symptoms, thought disorder, and delusions/hallucinations. Dimensionality could meaningfully be increased to five components. Negative symptoms was found to separate into two components that we labeled negative signs and social dysfunctions. The delusions/hallucinations factor could be separated into two components, delusions and hallucinations, with “loss of boundary” delusions being related to both factors. Delusions of persecution were independent of other symptoms. The thought disorder factor did not decompose meaningfully within the investigated dimensionality. A two-factor solution did not explain the correlation between symptoms adequately. The results do not support the simple dichotomy between positive and negative symptoms in psychosis, but suggest that a wider dimensional concept may be more useful in future studies.