Fundamental Issues in Evaluating the Impact of Interventions: Sources and Control of Bias

Supino, Phyllis G.

doi:10.1007/978-1-4614-3360-6_5

Cited by 9 publications

(7 citation statements)

References 21 publications

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“…To combat this issue, we employed checks such as filler items in the SRSI and manipulation checks such as repeated intensity questions. The findings that truth tellers reported lower symptom intensity the second time, which might suggest presence of subject-expectancy effect (Supino, 2012). Our results showed that participants passed the checks for random responding, and that they were compliant with the instructions.…”

Section: Discussionsupporting

confidence: 52%

Verifiability and Symptom Endorsement in Genuine, Exaggerated, and Malingered Pain

Akca

Slootmaekers

Bošković

2020

Psychol. Inj. and Law

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The current study has investigated whether pure malingering, in which reported symptoms are nonexistent, partial malingering, in which existent symptoms are exaggerated, and genuine symptoms could be differentiated by applying the verifiability approach (VA) and the Self-Report Symptom Inventory (SRSI). The logic behind the VA is that deceivers' statements contain more nonverifiable information, whereas truth tellers' accounts include more verifiable details. The SRSI taps into over-reporting by including a mix of genuine symptoms and implausible complaints (pseudosymptoms). We checked if participants (N = 167) allocated to one of three conditions (pure malingerers vs. exaggerators vs. truth tellers) can be differentiated in their pain symptom reports' (non)verifiability and symptom endorsement. Findings revealed that deceptive reports were lengthier than truthful statements. However, this difference was not produced by a discrepancy in non-verifiable details, but rather by a higher production of verifiable information among malingerers and exaggerators. Thus, contrary to previous findings, our results indicate that pain reports rich in verifiable information should raise doubt about their veracity. Further, truth tellers endorsed less symptoms of the SRSI than exaggerators, but not than pure malingerers. Pure malingerers and exaggerators did not differ in symptom endorsement. Thus, our findings revealed that when compared with truth tellers, exaggerators exhibited stronger overreporting tendencies than (pure) malingerers. However, due to inconsistent findings, further investigation of the efficacy of these methods in differentiation between exaggerated and malingered reports is required.

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Section: Discussionsupporting

confidence: 52%

Verifiability and Symptom Endorsement in Genuine, Exaggerated, and Malingered Pain

Akca

Slootmaekers

Bošković

2020

Psychol. Inj. and Law

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“…Neglecting to report on blinding is common in many research studies but insufficient information regarding the Page 31 of 53 A c c e p t e d M a n u s c r i p t 31 blinding process or whether it was conducted can be misleading . If it was the case that blinding was not carried out, differential treatment of the participants by the outcome assessors could occur and influence the psychological response of participants (Supino, 2012). Some randomised studies were quite poorly conducted and/or neglectful in their reporting such as that of the RCTs by Pibernik-Okanovic et al (2009) The results of this review need to be taken with caution due to the biases previously mentioned.…”

Section: Quality Of Evidencementioning

confidence: 75%

Psychosocial interventions for people with diabetes and co-morbid depression. A systematic review

Kok

Williams

Zhao

2015

International Journal of Nursing Studies

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“…Therefore, part of stimulation outcomes may be induced by a strong placebo effect (Fonteneau et al 2019). tDCS, as a physically sensible intervention, can trigger expectations (positive or negative) and may affect overall outcomes (Supino 2012). Therefore, it is important to subtract the placebo effects caused by sham stimulation from active effects induced by active stimulation to determine the true effect induced by tDCS alone.…”

Section: Discussionmentioning

confidence: 99%

Transcranial Direct Current Stimulation to Modulate fMRI Drug Cue Reactivity in Methamphetamine Users: A Randomized Clinical Trial

Ekhtiari

Soleimani

Kuplicki

et al. 2021

Preprint

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Transcranial direct current stimulation (tDCS) has been studied as an adjunctive therapeutic option to alter maladaptive cortical excitability, activity, and connectivity associated with chronic substance use via the application of a weak direct current through the brain. The underlying mechanism of action remains ambiguous, however. We present a randomized, triple-blind, sham-controlled, clinical trial with two parallel arms conducted to determine the neural substrates of tDCS effects on drug craving using an fMRI drug cue reactivity paradigm. Sixty participants with methamphetamine use disorder were randomly assigned to two groups: 30 participants to active tDCS (5x7 cm2, 2 mA, for 20 minutes, anode/cathode over the F4/Fp1 in EEG 10-20 standard system) and 30 participants to the sham group. Neuroimaging data of a methamphetamine cue reactivity (MCR) task were collected immediately before and after stimulation with subjective craving assessed before, after, and during fMRI scans. There was a significant reduction in self-reported craving after stimulation (main effect of time) without any significant effect of group, time, or by group-time interaction. Our whole-brain analysis demonstrated that brain activation decreased in all parts of the brain in the second (post-stimulation) MCR imaging session after sham stimulation (habituation) but this uniform decrease did not occur throughout the brain in the active group. There were significant interactions between the group (active vs. sham) and time (after vs. before stimulation) in five main regions; medial frontal gyrus, anterior insula, inferior parietal lobule, precuneus, and inferior frontal gyrus with higher activations after active stimulation. We simulated computational head models for each individual. There was a significant effect of group in the relationship between level of current in the above-mentioned significant clusters and changes in task-modulated activation. We also found that brain regions with the highest electric fields in the prefrontal cortex showed a significant time by group interaction in task-modulated connectivity (psychophysiological interaction during MCR) in the frontoparietal network. In this two-parallel-arms triple-blind randomized control trial, we did not find any significant effect of the one session of active F4/Fp1 tDCS on drug craving self-report compared to sham stimulation. However, connectivity differences induced by active compared to sham stimulation suggested some potential mechanisms of tDCS to modulate neural response to drug cues among people with methamphetamine use disorder.

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Fundamental Issues in Evaluating the Impact of Interventions: Sources and Control of Bias

Cited by 9 publications

References 21 publications

Verifiability and Symptom Endorsement in Genuine, Exaggerated, and Malingered Pain

Verifiability and Symptom Endorsement in Genuine, Exaggerated, and Malingered Pain

Psychosocial interventions for people with diabetes and co-morbid depression. A systematic review

Transcranial Direct Current Stimulation to Modulate fMRI Drug Cue Reactivity in Methamphetamine Users: A Randomized Clinical Trial

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