Qualitative methods in early-phase drug trials : data and methods from a trial of N-acetylcysteine in schizophrenia

Objective: The pharmacokinetic profile of a drug often gives little indication of its potential therapeutic application, with many therapeutic uses of drugs being discovered serendipitously while being studied for different indications. As hypothesis-driven, quantitative research methodology is exclusively used in early-phase trials, unexpected but important phenomena may escape detection. In this context, this study aimed to examine the potential for integrating qualitative research methods with quantitative methods in early-phase drug trials. To our knowledge, this mixed methodology has not previously been applied to blinded psychopharmacologic trials.

Method: We undertook qualitative data analysis of clinical observations on the dataset of a randomized, double-blind, placebo-controlled trial of N-acetylcysteine (NAC) in patients with DSM-IV-TR–diagnosed schizophrenia (N = 140). Textual data on all participants, deliberately collected for this purpose, were coded using NVivo 2, and emergent themes were analyzed in a blinded manner in the NAC and placebo groups. The trial was conducted from November 2002 to July 2005.

Results: The principal findings of the published trial could be replicated using a qualitative methodology. In addition, significant differences between NAC- and placebo-treated participants emerged for positive and affective symptoms, which had not been captured by the rating scales utilized in the quantitative trial. Qualitative data in this study subsequently led to a positive trial of NAC in bipolar disorder.

Conclusions: The use of qualitative methods may yield broader data and has the potential to complement traditional quantitative methods and detect unexpected efficacy and safety signals, thereby maximizing the findings of early-phase clinical trial research.

Effect of subjective reasoning and neurocognition on medication adherence for persons with schizophrenia

Objective: This study investigated the relationship between patients' reasoning about medication adherence and neurocognitive and clinical indices for a treatment-compliant sample of Japanese patients with schizophrenia.

Methods: Subjective reasoning about medication adherence was assessed by the Rating of Medication Influences (ROMI) scale. General intelligence, executive function, and verbal memory were assessed by the Wechsler Adult Intelligence Scale-Revised, Wisconsin Card Sorting Test, and Rey Auditory Verbal Learning Test, respectively.

Results: Higher prevention scores were associated with lower executive functioning and older age. Influence of others was associated with years of education, medication dosage, and IQ, and medication affinity was associated with education.

Conclusions: These results suggest that executive functioning, education, and general IQ may all be important factors in individual motivation for medication adherence.