Failure to reach data saturation has an impact on the quality of the research conducted and hampers content validity. The aim of a study should include what determines when data saturation is achieved, for a small study will reach saturation more rapidly than a larger study. Data saturation is reached when there is enough information to replicate the study when the ability to obtain additional new information has been attained, and when further coding is no longer feasible. The following article critiques two qualitative studies for data saturation: Wolcott (2004) and Landau and Drori (2008). Failure to reach data saturation has a negative impact on the validity on one’s research. The intended audience is novice student researchers. Keywords: Data Saturation, Triangulation, Interviews, Personal Lens, Bias.

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Are We There Yet? Data Saturation in Qualitative Research

Irritable bowel syndrome

Content Validity—Establishing and Reporting the Evidence in Newly Developed Patient-Reported Outcomes (PRO) Instruments for Medical Product Evaluation: ISPOR PRO Good Research Practices Task Force Report: Part 1—Eliciting Concepts for a New PRO Instrument

https://digitalcommons.wayne.edu/cgi/viewcontent.cgi?article=1259&context=csr

Good Days, Bad Days: The Self in Chronic Illness and Time

Qualitative Methods in Psychology: A Research Guide.

Recently published articles have described criteria to assess qualitative research in the health field in general, but very few articles have delineated qualitative methods to be used in the development of Patient-Reported Outcomes (PROs). In fact, how PROs are developed with subject input through focus groups and interviews has been given relatively short shrift in the PRO literature when compared to the plethora of quantitative articles on the psychometric properties of PROs. If documented at all, most PRO validation articles give little for the reader to evaluate the content validity of the measures and the credibility and trustworthiness of the methods used to develop them. Increasingly, however, scientists and authorities want to be assured that PRO items and scales have meaning and relevance to subjects. This article was developed by an international, interdisciplinary group of psychologists, psychometricians, regulatory experts, a physician, and a sociologist. It presents rigorous and appropriate qualitative research methods for developing PROs with content validity. The approach described combines an overarching phenomenological theoretical framework with grounded theory data collection and analysis methods to yield PRO items and scales that have content validity.

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PRO development: rigorous qualitative research as the crucial foundation

Diarrhea-predominant irritable bowel syndrome (IBS-D) can considerably impact patients’ lives. Patient-reported symptoms are crucial in understanding the diagnosis and progression of IBS-D. This study psychometrically evaluates the newly developed IBS-D Daily Symptom Diary and Symptom Event Log (hereafter, “Event Log”) according to US regulatory recommendations. A US-based observational field study was conducted to understand cross-sectional psychometric properties of the IBS-D Daily Symptom Diary and Event Log. Analyses included item descriptive statistics, item-to-item correlations, reliability, and construct validity. The IBS-D Daily Symptom Diary and Event Log had no items with excessive missing data. With the exception of two items (“frequency of gas” and “accidents”), moderate to high inter-item correlations were observed among all items of the IBS-D Daily Symptom Diary and Event Log (day 1 range 0.67–0.90). Item scores demonstrated reliability, with the exception of the “frequency of gas” and “accidents” items of the Diary and “incomplete evacuation” item of the Event Log. The pattern of correlations of the IBS-D Daily Symptom Diary and Event Log item scores with generic and disease-specific measures was as expected, moderate for similar constructs and low for dissimilar constructs, supporting construct validity. Known-groups methods showed statistically significant differences and monotonic trends in each of the IBS-D Daily Symptom Diary item scores among groups defined by patients’ IBS-D severity ratings (“none”/“mild,” “moderate,” or “severe”/“very severe”), supporting construct validity. Initial psychometric results support the reliability and validity of the items of the IBS-D Daily Symptom Diary and Event Log.

/pdf/psychometric-assessment-of-the-ibs-d-daily-symptom-diary-and-2qsnhwrs5o.pdf

Psychometric assessment of the IBS-D Daily Symptom Diary and Symptom Event Log

Objectives: Chronic insomnia and depression are often associated. Measuring the impact on quality of life associated with changes in sleep in co-treatment of insomnia and depression requires a valid and reliable patient reported outcome (PRO) instrument. This study aimed to assess the validity of the Sleep Impact Scale (SIS), a sleep-specific PRO instrument, in a population comorbid with Major Depressive Disorder (MDD) and insomnia to support its use in clinical or clinical trial applications.Research design and methods: Data from 379 subjects enrolled in a 27 week US, multi-center, phase IV, randomized, double-blind, parallel group, placebo-controlled trial of zolpidem tartrate extended-release taken in combination with escitalopram vs. placebo combined with escitalopram were pooled across treatment groups. Results from multi-trait analyses, tests of internal consistency and test–retest reliability, concurrent validity, known-groups validity, responsiveness, and thresholds for minimal important d...

Validation of the sleep impact scale in patients with major depressive disorder and insomnia

Background: Available stool form scales do not optimally capture the continuum of stool consistency experienced by patients with irritable bowel syndrome with diarrhea (IBS-D). This paper describes the development of a new measure to assess stool form and consistency for IBS-D.
	Methods: Descriptors for a new scale were selected by comparing spontaneous descriptions of stools from patients with IBS-D (Rome III) with spontaneous patient descriptions of images in the Bristol Stool Form Scale (BSFS) and an adapted BSFS. New images were prepared by an artist based on the final descriptors and literature images. The new Astellas Stool Form Scale (ASFS) was assessed in cognitive interviews.
	Results: Spontaneous reports of stool descriptors from 50 patients with IBS-D were broadly grouped based on conceptual equivalence. From these, 8 final stool descriptors were selected, ranging from “like marbles or hard rocks” to “just liquid,” and an image was created for each descriptor. In 20 cognitive interviews, 75% of patients with IBS-D indicated that descriptors matched the appropriate images, 95% of patients indicated that there were enough images to depict each stool type, and 70% of patients indicated that all images were clear.
	Conclusion: The ASFS, developed using spontaneous patient reports and rigorous qualitative methods, was well understood by patients with IBS-D and was relevant to their experience of stool form and consistency with IBS-D. Further evaluation is ongoing to confirm its utility in clinical research and in the clinical setting as a tool to monitor change in patients with IBS-D and to assess treatments.

Development of a New Instrument to Assess Stool Form and Consistency in Irritable Bowel Syndrome with Diarrhea

Methods of treating and/or diagnosing irritable bowel syndrome (IBS) are provided, wherein treatment or diagnosis is undertaken on the basis of the patient's recordation of events associated with IBS in an event log and/or symptom diary.

Kathleen Rosa

Papers

PRO development: rigorous qualitative research as the crucial foundation

Psychometric assessment of the IBS-D Daily Symptom Diary and Symptom Event Log

Validation of the sleep impact scale in patients with major depressive disorder and insomnia

Development of a New Instrument to Assess Stool Form and Consistency in Irritable Bowel Syndrome with Diarrhea

Tool for assessment of symptoms of irritable bowel syndrome