Results of the first exploratory qualitative assessment of participants’ experiences of chronic daily administration of a multivitamin (MV) revealed significant effects in several areas. The major significant themes found between SMV and placebo concerned participants’ perceived increased energy levels and enhanced mood, with a trend towards some experiencing better sleep. We performed a double-blind analysis and utilised quantitative methods of data analysis (i.e. Chi square test), increasing confidence in these results.
While assessment on quantitative numerical assessment scales is considered the “gold standard”, use of qualitative methods, involving data from open-ended questions, clinician’s notes, and forums, may reveal outcomes that may not have been found by established quantitative assessment tools. This method has been used successfully in other nutraceuticals studies
[34, 35], but not yet for MV studies. As commented by Berk et al.
, unexpected but important phenomena may escape detection in purely quantitative studies. In their double-blind RCT involving the application of N-acetyl cysteine for schizophrenia, emergent themes arose which had not been captured by the quantitative rating scales utilised. Such identified novel effects can potentially factor into future practice guidelines, or can be specifically studied in subsequent RCTs.
The finding of participants reporting significantly increased mood and energy is in line with results of previous MV and B vitamin complex research; adequate B vitamin levels are critical for neuronal communication and energy generation. Importantly, very few participants experienced any negative effects, and no significant adverse reactions were identified in the study. The only cases of identified side effects concerned minor gastrointestinal symptoms; reactions such as nausea have been previously reported by a small percentage of the general public who take a MV
. Analysis by gender revealed that the observed benefit on mood and energy were more likely to be experienced by women than men.
Limitations of the qualitative component are acknowledged. The use of a written semi-structured assessment form does not provide the rich exploration of experience that can achieved from interviews with open-ended questions or focus groups, and the small sample size meant that only very common effects of SMV could be reliably detected. Additionally as the qualitative questions addressed perception of change due to treatment they were only completed at the final testing visit. An intent-to-treat analysis was therefore not possible for this data and only study completers were included in the analysis.
It should be noted that these analyses have not be corrected for multiple comparisons. When multiple outcome measures, such as our 21 themes, are assessed, a p-value correction may not always be the best approach as it can result in an overly conservative significance level and increased likelihood of a Type 2 error
. The themes seen here to benefit from multivitamin use are supported theoretically and by the supplementation effects seen in previous quantitative studies.
The qualitative data presented here provides the first exploration of the important topic of participants’ experiences and should prompt further, more in-depth investigation of this topic as part of future RCTs.