ArticleBMJ open2018
What is associated with increased side effects and lower perceived efficacy following switching to a generic medicine? A New Zealand cross-sectional patient survey.
Article in BMJ open, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 16 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
16 citing papers in PubMed, 1 synthesis or guideline pooled it, 30 citations in OpenAlex.
- Is There Any Research Evidence Beyond Surveys and Opinion Polls on Automatic Substitution of Biological Medicines? A Systematic Review.BioDrugs : clinical immunotherapeutics, biopharmaceuticals and gene therapy · 2021Pooled it
- Drug Brand Switching: A Regulatory Perspective.Drug safety · 2026Review
- Influence of sex and gender-related factors on the knowledge of generic medicines among older patients and caregivers.Internal and emergency medicine · 2026Article
- Social media use and expectations predict COVID-19 vaccine side effects: a prospective longitudinal study.Frontiers in psychology · 2026Article
- Insulin Glargine Biosimilar Prescribing and Cost Trends in the United Kingdom's Primary Care from 2020 to 2024.Pharmacy (Basel, Switzerland) · 2025Article
- Challenges for switching central nervous system and psychiatric medication products: A review of the literature.Journal of psychopharmacology (Oxford, England) · 2025Review
- Predicting the side effects of influenza vaccination.Annals of behavioral medicine : a publication of the Society of Behavioral Medicine · 2025Article
- Development and validation of the General attitude towards Medication Questionnaire (GAMQ).BMC psychology · 2024Article
- Tolerability and Acceptance of Switching from Brand to Generic Glatiramer Acetate in Multiple Sclerosis.Journal of clinical medicine · 2024Article
- Health Scares: Tracing Their Nature, Growth and Spread.Clinical psychology in Europe · 2023Article
- Patients' Experience of Medication Brand Changes during Hormone Therapy for Breast Cancer-An Interpretative Phenomenological Analysis.Healthcare (Basel, Switzerland) · 2022Article
- Article
- Patient experiences of switching from Efavirenz- to Dolutegravir-based antiretroviral therapy: a qualitative study in Uganda.BMC infectious diseases · 2021Article
- Patients' beliefs and behaviours are associated with perceptions of safety and concerns in a hypothetical biosimilar switch.Rheumatology international · 2021Article
- The Effect of Television and Print News Stories on the Nocebo Responding Following a Generic Medication Switch.Clinical psychology in Europe · 2020Article
- Study of mental health outcomes associated with different brands of venlafaxine at the Kumeu medical centre from January 2017 to October 2018.Therapeutic advances in psychopharmacology · 2020Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectiveFollowing a switch from either a generic or branded antidepressant (venlafaxine) to a new generic, we investigated the factors associated with a preference for branded medicines, side effects reported following switching and efficacy ratings of the new generic drug.
designA cross-sectional survey of patients switched to a new generic.
settingPatients accessing venlafaxine information online from the New Zealand government pharmaceuticals funding website.
participants310 patients, comprising 205 originally on branded venlafaxine and 105 previously taking a generic version.
main outcome measuresAn online questionnaire assessing demographic factors, perceived sensitivity to medicines, trust in pharmaceutical agencies, sources of switch information, preference for branded medicine, new medicine perceptions, side effects and efficacy ratings.
resultsPreference for branded medicine was significantly stronger in older patients (OR=1.04, 95% CI 1.01 to 1.05), those taking branded venlafaxine (OR=2.02, 95% CI 1.13 to 3.64) and patients with a higher perceived sensitivity to medicine (OR=1.23, 95% CI 1.06 to 1.19). Different factors predicted side effects in those switching from the branded and those switching from the generic venlafaxine. Trust in pharmaceutical agencies and the number of side effects were significant predictors of efficacy ratings of the new generic in both patients switching from a branded and those switching from a generic version of venlafaxine.
conclusionsIn patients switching from a branded medicine and those already taking a generic, different demographic and psychological factors are associated with preference for branded medicine, side effect reporting and perceived efficacy of the new drug. When switching to new generic, there appears to be a close bidirectional relationship between the experience of side effects and perceived drug efficacy. Trust in pharmaceutical agencies impacts directly on perceived efficacy and increasing such trust could reduce the nocebo response following a generic switch.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.