Biography:

In the past Stephen P. McKenna has collaborated on articles with James Twiss and David M. Meads. One of their most recent publications is ReviewA new measure of quality of life in depression: Testing the reliability and construct validity of the QLDS. Which was published in journal Health Policy.

More information about Stephen P. McKenna research including statistics on their citations can be found on their Copernicus Academic profile page.

Stephen P. McKenna's Articles: (6)

ReviewA new measure of quality of life in depression: Testing the reliability and construct validity of the QLDS

AbstractOur previous paper described the development of a new quality of life scale for use with people suffering from depression; the Quality of Life in Depression Scale (QLDS). This paper reports on the testing of the scale for reliability and construct validity. Reliability was assessed by giving the questionnaire to the same set of patients on two occasions 2 weeks apart. This test-retest technique yielded a correlation of 0.94, with high internal consistency at both time 1 and time 2. A test of split-half reliability also indicated vey high reliability. Construct validity was measured by comparing scores on the QLDS with those on an established scale of well-being from the same group of patients. The results gave a correlation between the two measures of 0.79, giving a satisfactory validity. It is concluded that the QLDS is a reliable and valid measure which is easy to use and acceptable to patients. Further tests of discriminative, concurrent and criterion validity are planned.

Original ArticleCan We Rely on the Dermatology Life Quality Index as a Measure of the Impact of Psoriasis or Atopic Dermatitis?

The Dermatology Life Quality Index (DLQI) is a widely used health-related quality of life measure. However, little research has been conducted on its dimensionality. The objectives of the current study were to apply Rasch analysis to DLQI data to determine whether the scale is unidimensional, to assess its measurement properties, test the response format, and determine whether the measure exhibits differential item functioning (DIF) by disease (atopic dermatitis versus psoriasis), gender, or age group. The results show that there were several problems with the scale, including misfitting items, DIF by disease, age, and gender, disordered response thresholds, and inadequate measurement of patients with mild illness. As the DLQI did not benefit from the application of Rasch analysis in its development, it is argued that a new measure of disability related to dermatological disease is required. Such a measure should use a coherent measurement model and ensure that items are relevant to all potential respondents. The current use of the DLQI as a guide to treatment selection is of concern, given its inadequate measurement properties.

Development and validation of the Asthma Life Impact Scale (ALIS)

SummaryBackgroundCurrent asthma patient-reported outcome (PRO) measures focus on symptoms and functioning and may not capture the holistic impact of asthma on the quality of life of the patient.ObjectiveTo develop a PRO measure capturing the overall impact of asthma on patient's quality of life.MethodsItems for the Asthma Life Impact Scale (ALIS) were generated from patients with asthma during interviews in the UK and focus groups in the US. The ALIS was tested with UK and US asthma patients during cognitive debriefing interviews and included in large, two-administration, validation studies in the UK and US.ResultsIssues raised by asthma patients during interviews (n = 39 patients) and focus groups (n = 16 patients) were included in the draft ALIS. Cognitive debriefing interviews with 29 UK and US asthma patients showed that the scale was relevant and comprehensive. 140 UK and 185 US asthma patients participated in the validation study. The analysis showed that the ALIS measures a single construct, namely the overall impact of asthma on patients' quality of life. Internal consistency (Cronbach's Alpha) was high (UK = 0.94; US = 0.92) as was test-retest reliability (UK = 0.93; US = 0.83). Patients reporting worse general health or more severe asthma had significantly higher ALIS scores (p < 0.001) (indicating greater negative impact of asthma). Correlations with the Asthma Quality of Life Questionnaire were moderate to high.ConclusionsThe final 22-item ALIS is unidimensional, reliable and valid, and a valuable tool for comprehensively assessing the holistic impact of asthma from the patient's perspective.

The Development of the Herpes Symptom Checklist and the Herpes Outbreak Impact Questionnaire

AbstractObjectiveTo develop measures of the day-to-day symptomatic and functional impact of recurrent genital herpes (RGH) outbreaks. The Herpes Outbreak Impact Questionnaire (HOIQ) and the Herpes Symptom Checklist (HSC) were designed to be acceptable to clinical professionals and to reflect patients' experience.MethodsScale content was derived via literature review and interviews with RGH patients and physicians. Questionnaires were assessed for face/content validity in the UK and the language checked for acceptability in the United States. The US measures were assessed for face/content validity with patients. Scaling/psychometric properties were determined via web survey. Participants completed the questionnaires twice during an outbreak, with 24 to 72 hours between administrations.ResultsRespondents found the questionnaires relevant and easy to understand and complete. Application of Rasch analysis resulted in the removal of two HOIQ items. Both scales were found to be unidimensional. Item stability testing for the HOIQ indicated that the measure is reproducible. Internal consistency was good (alpha: time 1 = 0.87, time 2 = 0.91). Discriminative validity was demonstrated by the measure's ability to distinguish between individuals who differed by self-reported severity of outbreak. The HOIQ and HSC were both responsive to change over time.ConclusionsThe HSC and the HOIQ can determine the impact of a herpes outbreak effectively. They are designed to be used daily during such outbreaks and to determine the effectiveness of RGH treatment.

International Development of the Patient-Reported Outcome Indices for Multiple Sclerosis (PRIMUS)

AbstractBackgroundThe Patient-Reported Indices for Multiple Sclerosis (PRIMUS) comprises a suite of three scales for assessing symptoms, activity limitations, and quality of life in multiple sclerosis (MS). It was developed in the UK and has been shown to have excellent psychometric properties. This study describes the adaptation of eight language versions for Canadian English, Canadian French, French, German, Italian, Spanish, Swedish, and US English.MethodsThe PRIMUS was translated using the dual-panel process. Cognitive debriefing interviews conducted with MS patients assessed face and content validity. Psychometric and scaling properties were assessed via a two-administration postal survey conducted in each country involving the PRIMUS, the Nottingham Health Profile (NHP), the Unidimensional Fatigue Impact Scale (U-FIS), and demographic questions.ResultsCognitive debriefing interviews demonstrated the acceptability of the new language versions. Analysis of survey data showed that the new language versions of the three PRIMUS scales were unidimensional (as indicated by fit to the Rasch model) and that they had good internal consistency and reproducibility. PRIMUS scale scores correlated as expected with those on the NHP and the U-FIS. The scales in all countries were able to discriminate between groups of patients on the basis of their self-reported MS severity, general health, and employment status.ConclusionsThe PRIMUS was successfully adapted into eight new languages. Most of the tests showed the PRIMUS to have good unidimensionality and to have good internal consistency, reproducibility, and construct validity. The measure is now available for use in clinical studies and trials involving these countries and the UK. Further work is required to assess the measure's responsiveness.

Original articleThe impact of Home Parenteral Nutrition on the lives of adults with Type 3 Intestinal Failure

Highlights•HPN, while life-saving, imposes restrictions on the lives of patients.•Quality of life is reduced because HPN prevents the fulfilment of basic human needs.•Needs impaired include autonomy, role fulfilment, esteem, attractiveness and safety.

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