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Journal ArticleDOI

Parental Expectation of Side Effects Following Vaccination Is Self-fulfilling: A Prospective Cohort Study.

01 Mar 2019-Annals of Behavioral Medicine (Oxford Academic)-Vol. 53, Iss: 3, pp 267-282
TL;DR: Investigation of psychological factors associated with parental report of side effects following vaccination with the child influenza vaccine, and parental intention to re-vaccinate one's child the following year found side effects perception is influenced by psychological factors, in particular expectations.
Abstract: Background One of the major factors contributing to parental refusal of vaccinations is the perception that vaccines cause side effects. Although symptoms are commonly reported following vaccinations, their causes are not always straightforward. Although some may be directly attributable to the vaccine itself, others may reflect pre-existing or coincidental symptoms that are misattributed to the vaccine. Purpose To investigate psychological factors associated with parental report of side effects following vaccination with the child influenza vaccine, and parental intention to re-vaccinate one's child the following year. Methods A prospective cohort study was run in primary care practices in London in the 2016-2017 influenza season (ClinicalTrials.gov number NCT02909855). Two hundred seventy parents from 14 practices completed a questionnaire before their child's vaccination. Follow-up questionnaires were completed 3 days after vaccination and one month after vaccination. Parental report of side effects and vaccination intention for the subsequent year were measured. Results Parental report of side effects was strongly associated with pre-vaccination expectation of side effects. Suggestions received from the media, National Health Service (NHS) vaccination leaflet, and health care workers, as well as uncertainty-related beliefs, perceived sensitivity of the child to medicines, pessimism, and anxiety were also associated with reporting side effects. Side effect report was associated with lower vaccination intention for the following influenza season. Conclusions Side effect perception following vaccination is influenced by psychological factors, in particular expectations. Perceiving side effects reduces future vaccination intention. Future public health communications should aim to decrease unrealistic expectations of side effects to increase vaccine uptake.

Summary (4 min read)

Introduction

  • In England, routine vaccination of children for influenza began in 2013 (1).
  • Research by their group indicates that parents who perceived side-effects in their child following vaccination for influenza in the 2015/16 season were less likely to intend to revaccinate their child the following year (9).
  • Symptom perception in oneself has also been associated with perceived sensitivity to medicines (12, 13), modern health worries (14- 19) and personality traits such as anxiety (20) and negative affect (12, 21, 22).
  • For some of these factors, the potential for a vicious circle exists.
  • In contrast to what the authors know about perception of symptoms in oneself, limited, mainly poor quality research exists investigating parental perception of symptoms in one’s child.

Methods

  • Design Participants in this prospective cohort study completed questionnaires before their child received the influenza vaccine for the 2016/17 influenza season (T1), three days after their vaccination (perception, T2) and one month after their vaccination (recall, T3).
  • The authors based their sample size calculation on the ability to detect a small odds ratio of 1.6 (45) for symptom perception between parents with high and low expectation of symptoms.
  • Clinical trial data suggest that 47.9% of children who received the Fluenz tetra vaccine report a symptom (46).
  • Potential participants were identified by eleven primary care practices in South London and were sent letters informing them about the study.
  • Full study materials can be found in the supplementary materials.

Outcome measures

  • The authors asked parents at T2 and T3 if they thought their child had “experienced any of the following side-effects because of their latest child flu vaccine.”.
  • For their list of side-effects, the authors used an adapted parent-report form of the patient health questionnaire (48), to which were added potential side-effects of the vaccine listed in the patient information leaflet (46) and a more general non-specific symptom (the child being “not themselves”) that was recommended when the materials were piloted with 11 parents.
  • This symptom list has been used in a previous nationally-representative study by their group (9).
  • Intention to vaccinate in the 2017/18 influenza season was measured at T2 and T3 by two items adapted from Payaprom et al. (49) (“I want [child] to be vaccinated for flu next year” and “I intend [child] to be vaccinated for flu next year”) which were rated on a five-point Likert scale from “strongly disagree” to “strongly agree.”.

Symptoms prior to vaccination

  • A child’s existing symptoms at the time of vaccination were measured by asking parents if their child had “shown signs of any of the following symptoms in the last 24 hours.”.
  • The list of symptoms provided was the same as that used in their outcome measure.

Expectation

  • A direct measure of expectation asked parents how likely it was that their child would “get short term side-effects from the flu vaccine” on a five-point Likert scale of “very unlikely” to “very likely.”.
  • Parents were also asked how likely five different sources (friends and family, official websites and departments, the media, the NHS influenza vaccination leaflet, and the health care worker) had said side-effects were from the vaccine, and their trust in these sources of information.
  • All expectation questions were asked at T1 apart from those relating to the suggestion of side-effects from the heath care worker as these could not be asked until after the vaccination appointment had taken place, at T2.
  • Parents who indicated their child had experienced side-effects from previous influenza vaccinations were asked how severe the side-effects were and how worried they had been.
  • Parents who indicated their child had experienced side-effects from other routine childhood vaccinations were asked how worried they had been.

Psychological traits

  • Participants completed four personality measures at T2. Participants’ trait anxiety was measured by the short form of the State-Trait Anxiety Inventory (STAI-T) (50).
  • Trait affect was measured using the short form Positive and Negative Affect Schedule (51).
  • Participants’ neuroticism was measured using the neuroticism items from an abbreviated form of the Eysenck Personality Questionnaire – Revised (EPQR-A) (52).
  • Perceptions about other medicines and technologies Participants’ perception of their child’s sensitivity to medicines was measured at both T1 and T3 using an adapted parental report version of the Perceived Sensitivity to Medicines questionnaire (PSM) (13).
  • Attitudes towards influenza and the vaccine Attitudes towards influenza and the child influenza vaccine were measured at T1 by a series of fifteen statements used in a previous study by their group (9).

Personal and clinical characteristics

  • Participants were asked for their age and gender.
  • Clinical characteristics, such as whether the parent or child had a long-term health condition and whether there were any people ‘at risk’ for influenza in the child’s household were also asked.
  • Procedure Ethical approval for the study was granted by the NHS Research Ethics Committee (Reference: IRAS ID: 192325, REC reference: 16/LO/1003).
  • Parents completed T1 materials in the waiting room at the primary care practice immediately prior to their child’s vaccination appointment, or online before their child’s vaccination appointment.
  • Separate logistic regressions were used to determine whether pre-existing symptoms; expectation for the child to develop side-effects; previous experience of side-effects; personality traits; perceptions; attitudes; and personal and clinical characteristics predicted perception of side effects at T2 and T3.

Expectations as a mediating variable

  • Zero-order correlations were run to identify factors that were correlated with direct expectations of the child developing side-effects and side-effect report at T2 and T3.
  • Factors that were correlated with both direct expectations and side-effect report at either T2 or T3 were entered into mediation analyses using the method described in Mackinnon (56).
  • Mediation using standardised coefficients was run to see whether the report of side-effects was mediated by expectation.
  • 95% confidence intervals were computed using bootstrapping (2000 repetitions) and were bias-corrected.
  • Personal and clinical characteristics were entered into the model as covariates.

Predictors of vaccination intention

  • Answers to vaccination intention questions were dichotomised, with participants coded as ‘definitely intending’ to vaccinate their child (answered “agree” or “strongly agree” to both questions) or ‘not definitely intending’ to vaccinate (answered “neither agree nor disagree,” “disagree” or “strongly disagree” to one or both questions).
  • Where participants only completed one follow-up questionnaire the authors used the data available to us to classify their response as either ‘definitely intend’ or ‘do not definitely intend’ to vaccinate.
  • Where participants completed both T2 and T3 and had concordant intentions, the authors classified them as either ‘definitely intend’ or ‘do not definitely intend’ as appropriate.
  • Logistic regression analyses were used to identify whether report of a side-effect at T2 or T3; worry about and perceived severity of these side-effects; suggestion that the child would experience side-effects by a health care worker; and change in the child’s perceived sensitivity to medicines, predicted intention to re-vaccinate the child in the next influenza season.
  • For these analyses, perceived sensitivity to medicines at T1 was controlled for (57).

Sensitivity analyses

  • Sensitivity analyses indicated that there were no substantial differences to the results when taking into account the effect of clustering by primary care practice.
  • Only two results were changed: worry about side-effects at T3 was no longer significantly associated with intention to vaccinate; and side-effects recalled at T3 was no longer significantly associated with change in parental perceived sensitivity to medicines.
  • For the mediation analyses, there was no difference to the strength or the significance of any of the main pathway effects.
  • Thus, clustering should not change the results of the binary_mediation analysis macro.

Results

  • Participants 270 participants were recruited from fourteen primary care practices.
  • At T3, parents were more likely to recall that their child had experienced side-effects if they had expected side-effects; perceived a suggestion of side-effects from the NHS vaccination leaflet; had high trait anxiety; high pessimism; and if they perceived their child to be sensitive to medicines.
  • When controlling for personal and clinical characteristics, there was an indirect effect of suggestion of side-effects from the media (β=.103, 95% CI [.005 to .251]; see Table 4) through expectation on side-effects reported at T2.
  • Parent age was associated with intention, with parents aged 35 to 44 having higher vaccination intention.

Discussion

  • Concern about side-effects is a common reason for declining vaccination (4).
  • In terms of practical implications, these results suggest that reducing expectations may help limit the perception of side-effects.
  • Parents are unable to access bodily cues and sensations, but must attend to and interpret their child’s behaviour (61).
  • Third, the interpretation of some results should be taken with caution due to low numbers and resulting wide confidence intervals.
  • The authors study suggests that in order to decrease side-effect perception and recall, and increase vaccination intention, parental expectations of side-effects following vaccination should be minimised, and that parents should be reassured about the generally mild nature of these sideeffects.

Compliance with Ethical Standards

  • The authors declare that they have no conflict of interest.
  • All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
  • Informed consent Prior to completing T1 materials, consent was obtained from all parents following standard practice from their research ethics committee.

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King’s Research Portal
DOI:
10.1093/abm/kay040
Document Version
Peer reviewed version
Link to publication record in King's Research Portal
Citation for published version (APA):
Smith, L., Weinman, J., Amlôt, R., Yiend, J., & Rubin, G. J. (2018). Parental expectation of side-effects following
vaccination is self-fulfilling: a prospective cohort study. Annals of Behavioral Medicine.
https://doi.org/10.1093/abm/kay040
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Download date: 09. Aug. 2022

1
Abstract
Background: One of the major factors contributing to parental refusal of vaccinations is the
perception that vaccines cause side-effects. While symptoms are commonly reported
following vaccinations, their causes are not always straightforward. Although some may be
directly attributable to the vaccine itself, others may reflect pre-existing or coincidental
symptoms that are misattributed to the vaccine.
Purpose: To investigate psychological factors associated with parental report of side-effects
following vaccination with the child influenza vaccine, and parental intention to re-vaccinate
one’s child the following year.
Methods: A prospective cohort study was run in primary care practices in London in the
2016/17 influenza season (ClinicalTrials.gov number NCT02909855). 270 parents from
fourteen practices completed a questionnaire before their child’s vaccination. Follow-up
questionnaires were completed three days after vaccination and one month after vaccination.
Parental report of side-effects and vaccination intention for the subsequent year were
measured.
Results: Parental report of side-effects was strongly associated with pre-vaccination
expectation of side-effects. Suggestions received from the media, NHS vaccination leaflet
and health care workers, as well as uncertainty-related beliefs, perceived sensitivity of the
child to medicines, pessimism and anxiety were also associated with reporting side-effects.
Side-effect report was associated with lower vaccination intention for the following influenza
season.
Conclusions: Side-effect perception following vaccination is influenced by psychological
factors, in particular expectations. Perceiving side-effects reduces future vaccination

2
intention. Future public health communications should aim to decrease unrealistic
expectations of side-effects in order to increase vaccine uptake.
Key words: influenza, child vaccination, attitudes, symptom, psychological factors

3
Introduction
In England, routine vaccination of children for influenza began in 2013 (1). Although the
vaccine is provided for free, uptake remains low, with vaccination targets of 40% in two to
four year olds set by Public Health England not being reached in the 2015/16 and 2016/17
influenza seasons (2, 3). There has been much research conducted on factors associated with
vaccine uptake, with a number of systematic reviews consistently finding the perception that
the vaccine causes side-effects to be associated with vaccination refusal (4-7).
Although side-effects from the influenza vaccine are mostly “mild in nature and short term”
(8), research by our group indicates that parents who perceived side-effects in their child
following vaccination for influenza in the 2015/16 season were less likely to intend to re-
vaccinate their child the following year (9). This issue is particularly problematic for the child
influenza vaccine as clinical trial data indicate that 47.9% of children will experience side-
effects following vaccination (8), yet children need to be re-vaccinated each year.
To date, there has been little research exploring the factors that contribute to parental
perception of side-effects in one’s child. Understanding what determines whether parents
perceive symptoms in their child has implications not just for our understanding of how their
attitudes towards vaccinations develop, but also for our understanding of treatment decisions
made on behalf of the child more generally (10) and on the burden to health care services if
parents overestimate the presence or severity of a symptom (9, 11).
Research has identified associations between a number of psychological factors and symptom
perception in oneself. One study, investigating the incidence of side-effects following travel
vaccinations, found that adults who were already symptomatic at the time of vaccination
reported more symptoms following vaccination (12). Symptom perception in oneself has also
been associated with perceived sensitivity to medicines (12, 13), modern health worries (14-

4
19) and personality traits such as anxiety (20) and negative affect (12, 21, 22). Increases in
symptom reports have been shown following news coverage about the side-effects of a
medication (23) and following observation of symptoms in others (24), something which may
be more apparent in females than in males (24, 25). Negative beliefs about medicines are
associated with higher expectations of side-effects (26) and misattribution of nonspecific
symptoms to medications (27). For some of these factors, the potential for a vicious circle
exists. For example, if perceived sensitivity to medicines facilitates the development of
symptoms after a medicine is taken, this may reinforce a patient’s view of themselves as
sensitive.
In contrast to what we know about perception of symptoms in oneself, limited, mainly poor
quality research exists investigating parental perception of symptoms in one’s child. Studies
suggest that some factors associated with symptom perception in the self may also be
implicated in parental perception of symptoms. For example, parental symptom perception
has been associated with an expectation for medication to cause side-effects (28, 29), and
social observation of symptoms in others (9). General attitudes, such as being concerned
about the safety of a vaccine and not liking vaccinations for the child have also been
associated with parental symptom perception (9, 30). Parents are more likely to perceive
symptoms in their child if the child has a history of symptoms, or is currently experiencing
nonspecific symptoms (31-37), or if the child has a chronic health problem (9, 35, 38-41).
Parents with increased anxiety report more symptoms in their child (32-34, 42). However,
almost all research investigating factors associated with the perception of symptoms in the
child is cross-sectional, limiting our ability to infer causality.
Although parents may perceive side-effects in their child immediately following their
influenza vaccination (43), their decision to re-vaccinate their child occurs one year later.
Recall of symptoms is often inaccurate, and may be influenced by different factors to

Citations
More filters
Journal ArticleDOI
TL;DR: Fear of side‐effects can result in non‐adherence to medical interventions, such as medication and chemotherapy, and research investigating predictors of side-effect expectations is disparate.
Abstract: Background: Fear of side-effects can result in non-adherence to medical interventions, such as medication and chemotherapy. Side-effect expectations have been identified as strong predictors of later perception of side-effects. However, research investigating predictors of side-effect expectations is disparate. Objective: To identify factors associated with side-effect expectations. Search strategy: We systematically searched Embase, Ovid MEDLINE, Global Health, PsycARTICLES, PsycINFO, Web of Science and Scopus. Inclusion criteria: Studies were included if they investigated associations between any predictive factor and expectations of side-effects from any medical intervention. Data extraction and synthesis: We extracted information about participant characteristics, medication, rates of side-effects expected, and predictors of side-effect expectations. Data were narratively synthesised. Main results: We identified sixty-four citations, reporting on seventy-two studies. Predictors fell into five categories: personal characteristics; clinical characteristics; psychological traits and state; presentation format of information; and information sources used. Using verbal risk descriptors (e.g. ‘common’) compared to numerical descriptors (e.g. percentages), having lower quality of life or wellbeing, and currently experiencing symptoms were associated with increased side-effect expectations. Discussion and conclusions: Decreasing unrealistic side-effect expectations may lead to decreased experience of side-effects and increased adherence to medical interventions. Widespread communications about medical interventions should describe the incidence of side-effects numerically. Evidence suggests that clinicians should take particular care with patients with lower quality of life, who are currently experiencing symptoms and who have previously experienced symptoms from treatment. Further research should investigate different clinical populations and aim to quantify the impact of the media and social media on side-effect expectations.

22 citations

Journal ArticleDOI
TL;DR: The authors studied why some Korean parents hesitate to vaccinate their children by applying the health belief model and found the reasons for vaccine hesitancy and acceptance were similar to the results of international research.
Abstract: Objectives Vaccinations for infectious diseases are opposed despite their achievement, and this opposition has recently been revealed in Korea. However, research in Korea has not been vigorous. The authors studied why some Korean parents hesitate to vaccinate their children by applying the health belief model. Methods Parents who hesitate to vaccinate and parents who do not were surveyed in alternative education preschools and elementary schools. They were classified into four types of hesitancy and statistically compared. Results Among the 129 subjects, 43 vaccinated without hesitancy, 20 vaccinated on time with hesitancy, 32 vaccinated with a deliberate delay of one month or longer, and 34 did not vaccinate. Vaccination increased with an increase in the awareness that severe outcomes can occur when unvaccinated. Concerns about adverse reactions from vaccinations or direct/indirect experiences affected refusal. Furthermore, perceptions of the lack of meaningfulness of vaccinations, distrust of policy and safety management, influence of leaders or activists in joined organizations, and experts of Korean traditional or alternative medicine affected refusal. Explanations by doctors, text messages and mails from institutions, and concerns about disadvantages caused by not complying with government policies increased vaccination. Conclusions The reasons for vaccine hesitancy and acceptance were similar to the results of international research. Health authorities and professionals should communicate sufficiently and appropriately with hesitant parents and find ways to rationally resolve social conflicts. However, this sample was small and there is little Korean research, so more in-depth and diverse researchs are needed.

20 citations

Journal ArticleDOI
TL;DR: Test several EWS indicators measuring spatial coherence and autocorrelation for their ability to predict a critical transition corresponding to disease outbreaks and vaccine refusal in a multiplex network model find that mutual information and join count indicators provided the best EWS.
Abstract: The resurgence of infectious diseases due to vaccine refusal has highlighted the role of interactions between disease dynamics and the spread of vaccine opinion on social networks. Shifts between disease elimination and outbreak regimes often occur through tipping points. It is known that tipping points can be predicted by early warning signals (EWS) based on characteristic dynamics near the critical transition, but the study of EWS in coupled behaviour-disease networks has received little attention. Here, we test several EWS indicators measuring spatial coherence and autocorrelation for their ability to predict a critical transition corresponding to disease outbreaks and vaccine refusal in a multiplex network model. The model couples paediatric infectious disease spread through a contact network to binary opinion dynamics of vaccine opinion on a social network. Through change point detection, we find that mutual information and join count indicators provided the best EWS. We also show the paediatric infectious disease natural history generates a discrepancy between population-level vaccine opinions and vaccine immunity status, such that transitions in the social network may occur before epidemiological transitions. These results suggest that monitoring social media for EWS of paediatric infectious disease outbreaks using these spatial indicators could be successful.

15 citations


Additional excerpts

  • ...∑ ∑ ∑ ω ω ω = − = − − = N V x x N N x x V V x x [ , ] 12 ( ) , [ , ] 1 2 (1 )(1 ), [ , ] 1 2 , (4) s j k jk j k j k jk j k s s j k jk j k , 2...

    [...]

Journal ArticleDOI
TL;DR: Parent and child affect, and parental expectations and beliefs may influence parents’ cognition, causing them to pay more attention to their child, interpret their child’s behavior as symptomatic, and recall symptoms in the child.
Abstract: Objective Parents make important treatment decisions for their children based on symptoms they perceive their child to be experiencing. Multiple psychological factors are associated with subjective symptom perception, but factors affecting perception of symptoms in others have been explored less. We systematically reviewed the literature to identify parent and child psychological factors associated with parental report of physical symptoms in their child. Methods We searched Embase, Ovid, PsycINFO, and Scopus for studies that investigated associations between psychological factors and parental report of symptoms in their child. Results Thirty-six citations reporting on 34 studies that assessed the association between parent or child psychological factors and parental report of physical symptoms in the child were included in the review. Three main factors were identified as being associated with parental symptom report. First, there was evidence for an association between parental symptom report and affect, in particular parent and child anxiety. Second, child behavioral and conduct problems, and temperament-related challenges (problems with feeding and sleeping) were associated with parental symptom report. Third, parental expectations and beliefs that symptoms would occur were associated with parental symptom report, although few studies investigated these associations. Conclusions Parent and child affect, and parental expectations and beliefs may influence parents' cognition, causing them to pay more attention to their child, interpret their child's behavior as symptomatic, and recall symptoms in the child. Given the importance of parental perception of symptoms in driving decisions around care, additional research in this field is needed.

13 citations


Cites background or methods from "Parental Expectation of Side Effect..."

  • ...One of these studies also investigated parents’ expectation that their child would experience a symptom, finding an association between parental expectation of side-effects and later side-effect reporting (50)....

    [...]

  • ...Only four studies gave a justification for the sample size used (28, 42, 49, 50) (see Figure 2)....

    [...]

  • ...Affect Anxiety (55) / (40, 45-47, 50, 51, 52) (5, 22, 33, 41, 43) / (32) Depression (56) / (45-47) (34, 53, 55) (29, 41) / (22, 32, 43) Attention deficit and hyperactivity (5, 54) / (45-47) (31, 32, 43)...

    [...]

  • ...In particular, only one study investigated the effect of parental expectation of symptoms (50)....

    [...]

  • ...Poor temperament (45-47) / (35, 36, 55) Problem relationship with peers (54) / (32, 43, 4547) Parenting style / (36, 43) (35) Beliefs, attitudes and expectations Attitudes to intervention / (49, 50)...

    [...]

Journal ArticleDOI
01 Mar 2022
TL;DR: Findings from vaccine recipients in general and pregnant women in particular can improve vaccine acceptance and find further support for minor short-term side effects, within 3 days of receiving the Comirnaty vaccine.
Abstract: Background COVID-19 vaccine safety is of major interest worldwide, since there is no prior experience with it. Israel was one of the first countries to widely use the Comirnaty vaccine. Aim We aimed to assess the vaccine's short-term side effects directly from a large population and to predict influencing factors for self-reporting side effects. Methods In a retrospective cohort study, we investigated self-reported systemic vaccine side-effects using electronic surveys sent to vaccinated individuals between 20 December 2020 and 11 March 2021, within 3 days following administration of the first and second dose. We determined predictors for reporting systemic side effects by logistic regression. Results A total of 1,213,693 patients received at least one vaccine dose and 301,537 (24.8%) answered at least one survey. Among them, 68,162 (30.4%) and 89,854 (59.9%) individuals filled the first and the second dose surveys, respectively, and reported one or more side effects. Most common side effects were fatigue, headache and myalgia. Several respondents reported facial paraesthesia after first and second dose, respectively (n = 1,675; 0.7% and n = 1,601; 1.1%). Individuals younger than 40 years and women reported side effects more frequently than others, but pregnant women reported less. Pregnancy was a weak predictor for reporting any side effect in general and in particular fatigue, myalgia, headache, chills and fever. Conclusions We found further support for minor short-term side effects, within 3 days of receiving the Comirnaty vaccine. These findings from vaccine recipients in general and pregnant women in particular can improve vaccine acceptance.

9 citations

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TL;DR: Examination of the scale on somewhat different grounds, however, does suggest that future applications can benefit from its revision, and a minor modification to the Life Orientation Test is described, along with data bearing on the revised scale's psychometric properties.
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Book
17 Jan 2008
TL;DR: In this paper, the authors introduce the statistical, methodological, and conceptual aspects of mediation analysis applications from health, social, and developmental psychology, sociology, communication, exercise science, and epidemiology are emphasized throughout Singlemediator, multilevel, and longitudinal models are reviewed.
Abstract: This volume introduces the statistical, methodological, and conceptual aspects of mediation analysis Applications from health, social, and developmental psychology, sociology, communication, exercise science, and epidemiology are emphasized throughout Single-mediator, multilevel, and longitudinal models are reviewed The author's goal is to help the reader apply mediation analysis to their own data and understand its limitations Each chapter features an overview, numerous worked examples, a summary, and exercises (with answers to the odd numbered questions) The accompanying CD contains outputs described in the book from SAS, SPSS, LISREL, EQS, MPLUS, and CALIS, and a program to simulate the model The notation used is consistent with existing literature on mediation in psychology The book opens with a review of the types of research questions the mediation model addresses Part II describes the estimation of mediation effects including assumptions, statistical tests, and the construction of confidence limits Advanced models including mediation in path analysis, longitudinal models, multilevel data, categorical variables, and mediation in the context of moderation are then described The book closes with a discussion of the limits of mediation analysis, additional approaches to identifying mediating variables, and future directions Introduction to Statistical Mediation Analysis is intended for researchers and advanced students in health, social, clinical, and developmental psychology as well as communication, public health, nursing, epidemiology, and sociology Some exposure to a graduate level research methods or statistics course is assumed The overview of mediation analysis and the guidelines for conducting a mediation analysis will be appreciated by all readers

4,473 citations

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TL;DR: Two studies are reported describing the development of a short-form of the state scale of the Spielberger State-Trait Anxiety Inventory (STAI) for use in circumstances where the full-form is inappropriate, and the six-item version offers a briefer and just as acceptable scale for subjects while maintaining results that are comparable to those obtained using the full form.
Abstract: Two studies are reported describing the development of a short-form of the state scale of the Spielberger State-Trait Anxiety Inventory (STAI) for use in circumstances where the full-form is inappropriate. Using item-remainder correlations, the most highly correlated anxiety-present and anxiety-absent items were combined, and correlated with scores obtained using the full-form of the STAI. Correlation coefficients greater than .90 were obtained using four and six items from the STAI. Acceptable reliability and validity were obtained using six items. The use of this six-item short-form produced scores similar to those obtained using the full-form. This was so for several groups of subjects manifesting a range of anxiety levels. This short-form of the STAI is therefore sensitive to fluctuations in state anxiety. When compared with the full-form of the STAI, the six-item version offers a briefer and just as acceptable scale for subjects while maintaining results that are comparable to those obtained using the full-form of the STAI.

2,538 citations

Journal ArticleDOI
TL;DR: The PHQ-15 is a brief, self-administered questionnaire that may be useful in screening for somatization and in monitoring somatic symptom severity in clinical practice and research.
Abstract: OBJECTIVE Somatization is prevalent in primary care and is associated with substantial functional impairment and healthcare utilization. However, instruments for identifying and monitoring somatic symptoms are few in number and not widely used. Therefore, we examined the validity of a brief measure of the severity of somatic symptoms. METHODS The Patient Health Questionnaire (PHQ) is a self-administered version of the PRIME-MD diagnostic instrument for common mental disorders. The PHQ-15 comprises 15 somatic symptoms from the PHQ, each symptom scored from 0 ("not bothered at all") to 2 ("bothered a lot"). The PHQ-15 was administered to 6000 patients in eight general internal medicine and family practice clinics and seven obstetrics-gynecology clinics. Outcomes included functional status as assessed by the 20-item Short-Form General Health Survey (SF-20), self-reported sick days and clinic visits, and symptom-related difficulty. RESULTS As PHQ-15 somatic symptom severity increased, there was a substantial stepwise decrement in functional status on all six SF-20 subscales. Also, symptom-related difficulty, sick days, and healthcare utilization increased. PHQ-15 scores of 5, 10, 15, represented cutoff points for low, medium, and high somatic symptom severity, respectively. Somatic and depressive symptom severity had differential effects on outcomes. Results were similar in the primary care and obstetrics-gynecology samples. CONCLUSIONS The PHQ-15 is a brief, self-administered questionnaire that may be useful in screening for somatization and in monitoring somatic symptom severity in clinical practice and research.

2,451 citations

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Citing this paper Please note that where the full-text provided on King 's Research Portal is the Author Accepted Manuscript or Post-Print version this may differ from the final Published version. And where the final published version is provided on the Research Portal, if citing you are again advised to check the publisher 's website for any subsequent corrections.