Return to work and psychosocial trajectories after breast cancer: a longitudinal and sequential approach.

PURPOSE: We aimed to describe the psychosocial adjustments according to return to work (RTW) trajectories in breast cancer survivors (BCS) using a sequential and temporal approach. METHODS: We used BCS data included from February 2015 to April 2016 in the Longitudinal Study on Behavioural, Economic and Sociological Changes after Cancer (ELCCA) cohort. RTW trajectories were identified using the sequence analysis method followed by a clustering. Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale and the EORTC quality of life questionnaire was used at inclusion and all follow-up visits to assess Health-Related Quality of Life (HRQoL). RESULTS: Fifty-two BCS were included in the study among whom four clusters of RTW trajectories were identified and labeled: slow RTW (N = 10), quick RTW (N = 27), partial RTW (N = 8), and part-time work (N = 7). Quick and slow RTW clusters showed slightly lower baseline mean levels of anxiety and higher levels of HRQoL. In the 4 years following diagnosis, BCS in the quick RTW cluster tended to report higher HRQoL in terms of functioning and less symptoms of pain and fatigue while those in the partial RTW cluster showed a lower HRQoL on almost all dimensions. All clusters showed an increase in pain and fatigue symptoms until 6 months followed by a tendency to recover baseline levels. CONCLUSIONS: The results of this study suggest that BCS who return to full-time work (slow and quick RTW patterns) recover better than patients who return to part-time work (partial and part-time RTW patterns).

Response shift results of quantitative research using patient-reported outcome measures: a descriptive systematic review.

PURPOSE: The objective of this systematic review was to describe the prevalence and magnitude of response shift effects, for different response shift methods, populations, study designs, and patient-reported outcome measures (PROM)s. METHODS: A literature search was performed in MEDLINE, PSYCINFO, CINAHL, EMBASE, Social Science Citation Index, and Dissertations & Theses Global to identify longitudinal quantitative studies that examined response shift using PROMs, published before 2021. The magnitude of each response shift effect (effect sizes, R-squared or percentage of respondents with response shift) was ascertained based on reported statistical information or as stated in the manuscript. Prevalence and magnitudes of response shift effects were summarized at two levels of analysis (study and effect levels), for recalibration and reprioritization/reconceptualization separately, and for different response shift methods, and population, study design, and PROM characteristics. Analyses were conducted twice: (a) including all studies and samples, and (b) including only unrelated studies and independent samples. RESULTS: Of the 150 included studies, 130 (86.7%) detected response shift effects. Of the 4868 effects investigated, 793 (16.3%) revealed response shift. Effect sizes could be determined for 105 (70.0%) of the studies for a total of 1130 effects, of which 537 (47.5%) resulted in detection of response shift. Whereas effect sizes varied widely, most median recalibration effect sizes (Cohen's d) were between 0.20 and 0.30 and median reprioritization/reconceptualization effect sizes rarely exceeded 0.15, across the characteristics. Similar results were obtained from unrelated studies. CONCLUSION: The results draw attention to the need to focus on understanding variability in response shift results: Who experience response shifts, to what extent, and under which circumstances?

Unsupervised item response theory models for assessing sample heterogeneity in patient-reported outcomes measures.

PURPOSE: Unsupervised item-response theory (IRT) models such as polytomous IRT based on recursive partitioning (IRTrees) and mixture IRT (MixIRT) models can be used to assess differential item functioning (DIF) in patient-reported outcome measures (PROMs) when the covariates associated with DIF are unknown a priori. This study examines the consistency of results for IRTrees and MixIRT models. METHODS: Data were from 4478 individuals in the Alberta Provincial Project on Outcome Assessment in Coronary Heart Disease registry who received cardiac angiography in Alberta, Canada, and completed the Hospital Anxiety and Depression Scale (HADS) depression subscale items. The partial credit model (PCM) based on recursive partitioning (PCTree) and mixture PCM (MixPCM) were used to identify covariates associated with differential response patterns to HADS depression subscale items. Model covariates included demographic and clinical characteristics. RESULTS: The median (interquartile range) age was 64.5(15.7) years, and 3522(78.5%) patients were male. The PCTree identified 4 terminal nodes (subgroups) defined by smoking status, age, and body mass index. A 3-class PCM fits the data well. The MixPCM latent classes were defined by age, disease indication, smoking status, comorbid diabetes, congestive heart failure, and chronic obstructive pulmonary disease. CONCLUSION: PCTree and MixPCM were not consistent in detecting covariates associated with differential interpretations of PROM items. Future research will use computer simulations to assess these models' Type I error and statistical power for identifying covariates associated with DIF.

Identification of sources of DIF using covariates in patient-reported outcome measures: a simulation study comparing two approaches based on Rasch family models.

When analyzing patient-reported outcome (PRO) data, sources of differential item functioning (DIF) can be multiple and there may be more than one covariate of interest. Hence, it could be of great interest to disentangle their effects. Yet, in the literature on PRO measures, there are many studies where DIF detection is applied separately and independently for each covariate under examination. With such an approach, the covariates under investigation are not introduced together in the analysis, preventing from simultaneously studying their potential DIF effects on the questionnaire items. One issue, among others, is that it may lead to the detection of false-positive effects when covariates are correlated. To overcome this issue, we developed two new algorithms (namely ROSALI-DIF FORWARD and ROSALI-DIF BACKWARD). Our aim was to obtain an iterative item-by-item DIF detection method based on Rasch family models that enable to adjust group comparisons for DIF in presence of two binary covariates. Both algorithms were evaluated through a simulation study under various conditions aiming to be representative of health research contexts. The performance of the algorithms was assessed using: (i) the rates of false and correct detection of DIF, (ii) the DIF size and form recovery, and (iii) the bias in the latent variable level estimation. We compared the performance of the ROSALI-DIF algorithms to the one of another approach based on likelihood penalization. For both algorithms, the rate of false detection of DIF was close to 5%. The DIF size and form influenced the rates of correct detection of DIF. Rates of correct detection was higher with increasing DIF size. Besides, the algorithm fairly identified homogeneous differences in the item threshold parameters, but had more difficulties identifying non-homogeneous differences. Over all, the ROSALI-DIF algorithms performed better than the penalized likelihood approach. Integrating several covariates during the DIF detection process may allow a better assessment and understanding of DIF. This study provides valuable insights regarding the performance of different approaches that could be undertaken to fulfill this aim.

Interferon gamma-1b for the prevention of hospital-acquired pneumonia in critically ill patients: a phase 2, placebo-controlled randomized clinical trial.

PURPOSE: We aimed to determine whether interferon gamma-1b prevents hospital-acquired pneumonia in mechanically ventilated patients. METHODS: In a multicenter, placebo-controlled, randomized trial conducted in 11 European hospitals, we randomly assigned critically ill adults, with one or more acute organ failures, under mechanical ventilation to receive interferon gamma-1b (100 µg every 48 h from day 1 to 9) or placebo (following the same regimen). The primary outcome was a composite of hospital-acquired pneumonia or all-cause mortality on day 28. The planned sample size was 200 with interim safety analyses after enrolling 50 and 100 patients. RESULTS: The study was discontinued after the second safety analysis for potential harm with interferon gamma-1b, and the follow-up was completed in June 2022. Among 109 randomized patients (median age, 57 (41-66) years; 37 (33.9%) women; all included in France), 108 (99%) completed the trial. Twenty-eight days after inclusion, 26 of 55 participants (47.3%) in the interferon-gamma group and 16 of 53 (30.2%) in the placebo group had hospital-acquired pneumonia or died (adjusted hazard ratio (HR) 1.76, 95% confidence interval (CI) 0.94-3.29; P = 0.08). Serious adverse events were reported in 24 of 55 participants (43.6%) in the interferon-gamma group and 17 of 54 (31.5%) in the placebo group (P = 0.19). In an exploratory analysis, we found that hospital-acquired pneumonia developed in a subgroup of patients with decreased CCL17 response to interferon-gamma treatment. CONCLUSIONS: Among mechanically ventilated patients with acute organ failure, treatment with interferon gamma-1b compared with placebo did not significantly reduce the incidence of hospital-acquired pneumonia or death on day 28. Furthermore, the trial was discontinued early due to safety concerns about interferon gamma-1b treatment.

Anxiety and depression symptoms in relatives of moderate-to-severe traumatic brain injury survivors - A multicentre cohort.

INTRODUCTION: The prevalence and risk factors of anxiety and depression symptoms in relatives of moderate to severe traumatic brain injury (TBI) survivors have not been thoroughly investigated. METHODS: Ancillary study of a multicentric prospective randomized-controlled trial in nine university hospitals in 370 moderate-to-severe TBI patients. TBI survivor-relative dyads were included in the 6th month of follow-up. Relatives responded to the Hospital Anxiety and Depression Scale (HADS). The primary endpoints were the prevalence of severe symptoms of anxiety (HADS-Anxiety ≥ 11) and depression (HADS-Depression ≥ 11) in relatives. We explored the risk factors of severe anxiety and depression symptoms. RESULTS: Relatives were predominantly women (80.7%), spouse-husband (47.7%), or parents (39%). Out of the 171 dyads included, 83 (50.6%) and 59 (34.9%) relatives displayed severe symptoms of anxiety and depression, respectively. Severe anxiety symptoms in relatives were independently associated with the patient's discharge at home (OR 2.57, 95%CI [1.04-6.37]) and the patient's higher SF-36 Mental Health domain scores (OR 1.03 95%CI [1.01-1.05]). Severe depression symptoms were independently associated with a lower SF-36 Mental Health domain score (OR = 0.98 95%CI [0.96-1.00]). No ICU organization characteristics were associated with psychological symptoms in relatives. DISCUSSION: There is a high prevalence of anxiety and depression symptoms among relatives of moderate-to-severe TBI survivors at 6 months. Anxiety and depression were inversely correlated with the patient's mental health status at 6 months. CONCLUSIONS: Long-term follow-up must provide psychological care to relatives after TBI.

Does Differential Item Functioning Jeopardize the Comparability of Health-Related Quality of Life Assessment Between Patients and Proxies in Patients with Moderate-to-Severe Traumatic Brain Injury?

BACKGROUND: Health-related quality of life (HRQoL) is clearly recognized as a patient-important outcome in patients with traumatic brain injury (TBI). Patient-reported outcomes are therefore often used and supposed to be directly reported by the patients without interpretation of their responses by a physician or anyone else. However, patients with TBI are often unable to self-report because of physical and/or cognitive impairments. Thus, proxy-reported measures, e.g., family members, are often used on the patient's behalf. Yet, many studies have reported that proxy and patient ratings differ and are noncomparable. However, most studies usually do not account for other potential confounding factors that may be associated with HRQoL. In addition, patients and proxies can interpret some items of the patient-reported outcomes differently. As a result, item responses may not only reflect patients' HRQoL but also the respondent's (patient or proxy) own perception of the items. This phenomenon, called differential item functioning (DIF), can lead to substantial differences between patient-reported and proxy-reported measures and compromise their comparability, leading to highly biased HRQoL estimates. Using data from the prospective multicenter continuous hyperosmolar therapy in traumatic brain-injured patients study (240 patients with HRQoL measured with the Short Form-36 (SF-36)), we assessed the comparability of patients' and proxies' reports by evaluating the extent to which items perception differs (i.e., DIF) between patients and proxies after controlling for potential confounders. METHODS: Items at risk of DIF adjusting for confounders were examined on the items of the role physical and role emotional domains of the SF-36. RESULTS: Differential item functioning was evidenced in three out of the four items of the role physical domain measuring role limitations due to physical health problems and in one out of the three items of the role emotional domain measuring role limitations due to personal or emotional problems. Overall, despite an expected similar level of role limitations between patients who were able to respond and those for whom proxies responded, proxies tend to give more pessimistic responses than patients in the case of major role limitations and more optimistic responses than patients in the case of minor limitations. CONCLUSIONS: Patients with moderate-to-severe TBI and proxies seem to have different perceptions of the items measuring role limitations due to physical or emotional problems, questioning the comparability of patient and proxy data. Therefore, aggregating proxy and patient responses may bias HRQoL estimates and alter medical decision-making based on these patient-important outcomes.

Impact of response shift effects in the assessment of self-reported depression during treatment: Insights from a rTMS versus Venlafaxine randomized controlled trial.

PURPOSE: Patient-Reported Outcomes are essential to properly assess treatment effectiveness in randomized clinical trial (RCT) for Major Depressive Disorder (MDD). MDD self-assessment may vary over time depending on change in the meaning of patients' self-evaluation of depression, i.e. Response Shift (RS). Our aim was to investigate RS and its impact on different depression domains in a clinical trial comparing rTMS versus Venlafaxine. METHODS: The occurrence and type of RS was determined using Structural Equation Modeling applied to change over time in 3 domains (Sad Mood, Performance Impairment, Negative Self-Reference) of the short-form Beck Depression Inventory (BDI-13) in a secondary analysis of a RCT on 170 patients with MDD treated by rTMS, venlafaxine or both. RESULTS: RS was evidenced in the venlafaxine group in the Negative Self-Reference and Sad Mood domains. CONCLUSION: RS effects differed between treatment arms in self-reported depression domains in patients with MDD. Ignoring RS would have led to a slight underestimation of depression improvement, depending on treatment group. Further investigations of RS and advancing new methods are needed to better inform decision making based on Patient-Reported Outcomes.

Implications of the syntheses on definition, theory, and methods conducted by the Response Shift - in Sync Working Group.

PURPOSE: Our aim is to advance response shift research by explicating the implications of published syntheses by the Response Shift - in Sync Working Group in an integrative way and suggesting ways for improving the quality of future response shift studies. METHODS: Members of the Working Group further discussed the syntheses of the literature on definitions, theoretical underpinnings, operationalizations, and response shift methods. They outlined areas in need of further explication and refinement, and delineated additional implications for future research. RESULTS: First, the proposed response shift definition was further specified and its implications for the interpretation of results explicated in relation to former, published definitions. Second, the proposed theoretical model was further explained in relation to previous theoretical models and its implications for formulating research objectives highlighted. Third, ways to explore alternative explanations per response shift method and their implications for response shift detection and explanation were delineated. The implications of the diversity of the response shift methods for response shift research were presented. Fourth, the implications of the need to enhance the quality and reporting of the response shift studies for future research were sketched. CONCLUSION: With our work, we intend to contribute to a common language regarding response shift definitions, theory, and methods. By elucidating some of the major implications of earlier work, we hope to advance response shift research.

Posttraumatic growth inventory: challenges with its validation among French cancer patients.

BACKGROUND: The Posttraumatic growth inventory (PTGI) aims to assess the positive psychological changes that individuals can perceive after a traumatic life event such as a cancer diagnosis. Several French translations of the PTGI have been proposed, but comprehensive data on their psychometric properties are lacking. This study aimed to provide a more complete assessment of the psychometric properties of one of the most used PTGI translations in early-stage breast cancer and melanoma patients. METHODS: A sample of 379 patients completed the PTGI two years after their cancer diagnosis. A confirmatory analysis was first performed to determine whether the initial five-factor structure of the PTGI was adequate for this French version. As issues were identified in the translation and in the questionnaire structure, we performed an exploratory analysis to determine the most suitable structure for this questionnaire. Validity and reliability of the evidenced structured were then assessed. RESULTS: The exploratory analysis evidenced a four-factor structure close to the initial structure: four of the five initial domains were recovered, and items from the unrecovered domain were split into the other domains. This new structure showed good internal consistency and acceptable validity. CONCLUSIONS: This study highlights that the process of translation and cross-cultural validation of questionnaires is crucial to obtain valid and reliable psychometric instruments. We advise French psycho-oncology researchers and psychotherapists to (i) use the revised translation of Lelorain et al. (2010) proposed in this manuscript and (ii) use the four scores newly evidenced with a grouping of two response categories.

Evaluating the impact of calibration of patient-reported outcomes measures on results from randomized clinical trials: a simulation study based on Rasch measurement theory.

BACKGROUND: Meaningfully interpreting patient-reported outcomes (PRO) results from randomized clinical trials requires that the PRO scores obtained in the trial have the same meaning across patients and previous applications of the PRO instrument. Calibration of PRO instruments warrants this property. In the Rasch measurement theory (RMT) framework, calibration is performed by fixing the item parameter estimates when measuring the targeted concept for each individual of the trial. The item parameter estimates used for this purpose are typically obtained from a previous "calibration" study. But imposing this constraint on item parameters, instead of freely estimating them directly in the specific sample of the trial, may hamper the ability to detect a treatment effect. The objective of this simulation study was to explore the potential negative impact of calibration of PRO instruments that were developed using RMT on the comparison of results between treatment groups, using different analysis methods. METHODS: PRO results were simulated following a polytomous Rasch model, for a calibration and a trial sample. Scenarios included varying sample sizes, with instrument of varying number of items and modalities, and varying item parameters distributions. Different treatment effect sizes and distributions of the two patient samples were also explored. Cross-sectional comparison of treatment groups was performed using different methods based on a random effect Rasch model. Calibrated and non-calibrated approaches were compared based on type-I error, power, bias, and variance of the estimates for the difference between groups. RESULTS: There was no impact of the calibration approach on type-I error, power, bias, and dispersion of the estimates. Among other findings, mistargeting between the PRO instrument and patients from the trial sample (regarding the level of measured concept) resulted in a lower power and higher position bias than appropriate targeting. CONCLUSIONS: Calibration does not compromise the ability to accurately assess a treatment effect using a PRO instrument developed within the RMT paradigm in randomized clinical trials. Thus, given its essential role in producing interpretable results, calibration should always be performed when using a PRO instrument developed using RMT as an endpoint in a randomized clinical trial.

Intermittent theta burst stimulation (iTBS) versus 10 Hz high-frequency repetitive transcranial magnetic stimulation (rTMS) to alleviate treatment-resistant unipolar depression: A randomized controlled trial (THETA-DEP).

BACKGROUND: Recently intermittent theta burst stimulation (iTBS) proved to be non-inferior to conventional repetitive transcranial magnetic stimulation (10 Hz rTMS) in unipolar depression after failure of one antidepressant trial, but to date no randomized control trial assessed the ability of iTBS to improve depression level and quality of life in more resistant features of depression with a long-term (6 month) follow-up in comparison to 10 Hz rTMS. OBJECTIVES/HYPOTHESIS: The aim of our study was to compare the efficacy of 10 Hz rTMS and iTBS in treatment-resistant unipolar depression on response rates (50% decrease of MADRS scores at one month from baseline) and change in quality of life during a 6-month follow-up. In addition, we investigated whether some clinical features at baseline were associated with the response in the different groups. METHOD: Sixty patients were randomized in a double-blind, controlled study at the University Hospital Center of Nantes, and received 20 sessions of either rTMS or iTBS applied to the left dorsolateral prefrontal cortex targeted by neuronavigation. Statistical analysis used Fischer's exact test and Chi-square test as appropriate, linear mixed model, and logistic regression (occurrence of depressive relapse and factors associated with the therapeutic response). RESULTS: Included patients showed in mean more than 3 antidepressants trials. Response rates were 36.7% and 33.3%, and remission rates were 18.5% and 14.8%, in the iTBS and 10 Hz rTMS groups respectively. Both groups showed a similar significant reduction in depression scores and quality of life improvement at 6 months. We did not find any clinical predictive factor of therapeutic response in this sample. CONCLUSION: Our study suggests the clinical interest of iTBS stimulation (which is more time saving and cost-effective as conventional rTMS) to provide long-lasting improvement of depression and quality of life in highly resistant unipolar depression.

Feasibility of Combining Transcranial Direct Current Stimulation and Active Fully Embodied Virtual Reality for Visual Height Intolerance: A Double-Blind Randomized Controlled Study.

BACKGROUND: Transcranial Direct Current Stimulation (tDCS) and Virtual Reality Exposure Therapy (VRET) are individually increasingly used in psychiatric research. OBJECTIVE/HYPOTHESIS: Our study aimed to investigate the feasibility of combining tDCS and wireless 360° full immersive active and embodied VRET to reduce height-induced anxiety. METHODS: We carried out a pilot randomized, double-blind, controlled study associating VRET (two 20 min sessions with a 48 h interval, during which, participants had to cross a plank at rising heights in a building in construction) with online tDCS (targeting the ventromedial prefrontal cortex) in 28 participants. The primary outcomes were the sense of presence level and the tolerability. The secondary outcomes were the anxiety level (Subjective Unit of Discomfort) and the salivary cortisol concentration. RESULTS: We confirmed the feasibility of the association between tDCS and fully embodied VRET associated with a good sense of presence without noticeable adverse effects. In both groups, a significant reduction in the fear of height was observed after two sessions, with only a small effect size of add-on tDCS (0.1) according to the SUD. The variations of cortisol concentration differed in the tDCS and sham groups. CONCLUSION: Our study confirmed the feasibility of the association between wireless online tDCS and active, fully embodied VRET. The optimal tDCS paradigm remains to be determined in this context to increase effect size and then adequately power future clinical studies assessing synergies between both techniques.

Modeling repeated self-reported outcome data: A continuous-time longitudinal Item Response Theory model.

Item Response Theory (IRT) models have received growing interest in health science for analyzing latent constructs such as depression, anxiety, quality of life or cognitive functioning from the information provided by each individual's items responses. However, in the presence of repeated item measures, IRT methods usually assume that the measurement occasions are made at the exact same time for all patients. In this paper, we show how the IRT methodology can be combined with the mixed model theory to provide a longitudinal IRT model which exploits the information of a measurement scale provided at the item level while simultaneously handling observation times that may vary across individuals and items. The latent construct is a latent process defined in continuous time that is linked to the observed item responses through a measurement model at each individual- and occasion-specific observation time; we focus here on a Graded Response Model for binary and ordinal items. The Maximum Likelihood Estimation procedure of the model is available in the R package lcmm. The proposed approach is contextualized in a clinical example in end-stage renal disease, the PREDIALA study. The objective is to study the trajectories of depressive symptomatology (as measured by 7 items of the Hospital Anxiety and Depression scale) according to the time from registration on the renal transplant waiting list and the renal replacement therapy. We also illustrate how the method can be used to assess Differential Item Functioning and lack of measurement invariance over time.

Performance of a Rasch-based method for group comparisons of longitudinal change and response shift at the item level in PRO data: A simulation study.

The growing interest in patient perception and experience in healthcare has led to an increase in the use of patient-reported outcomes (PRO) data. However, chronically ill patients may regularly adapt to their disease and, as a consequence, might change their perception of the PRO being measured. This phenomenon named response shift (RS) may occur differently depending on clinical and individual characteristics. The RespOnse Shift ALgorithm at the Item level (ROSALI), a method for RS analysis at the item level based on Rasch models, has recently been extended to explore heterogeneity of item-level RS between two groups of patients. The performances of ROSALI in terms of RS detection at the item level and biases of estimated differences in latent variable means were assessed. A simulation study was performed to investigate four scenarios: no RS, RS in only one group, RS affecting both groups either in a similar or a different way. Performances of ROSALI were assessed using rates of false detection of RS when no RS was simulated and a set of criteria (presence of RS, correct identification of items and groups affected by RS) when RS was simulated. Rates of false detection of RS were low indicating that ROSALI satisfactorily prevents from mistakenly inferring RS. ROSALI is able to detect RS and identify the item and group(s) affected when RS affects all response categories of an item in the same way. The performances of ROSALI depend mainly on the sample size and the degree of heterogeneity of item-level RS.

Investigation of measurement invariance in longitudinal health-related quality of life in preemptive or previously dialyzed kidney transplant recipients.

PURPOSE: Kidney transplantation (KT) can impact patients' evaluation of health-related quality of life (HRQoL) as they adapt to their new life with a graft and its changes. Patients may adapt to KT in a different way, depending on whether they were on dialysis prior to transplantation or not (i.e. preemptive group). This may result in lack of measurement invariance between these patients' groups and/or over time (i.e. response shift, RS) which may invalidate the between-group comparison of HRQoL change scores. The aim of this study was to investigate and compare RS before and after KT between these two patients' groups. Measurement invariance was investigated between groups and over time with three measurement occasions. METHODS: Adult patients completed the SF-36 at the last visit before KT, and 3, 6 months after. A structural equation model-based procedure was used to (i) detect and take into account measurement non-invariance between groups and RS, if appropriate, (ii) identify the period of occurrence of RS, (iii) study the heterogeneity of RS between the two groups. RESULTS: Before KT (i.e. baseline), measurement invariance was not rejected between dialyzed (n = 196) and preemptive (n = 178) patients' groups. Between baseline and 3 months after KT, similar uniform recalibration was detected on the general health domain in both groups. Uniform recalibration was found between 3- and 6 months after KT on the vitality domain for preemptive patients only. CONCLUSION: HRQoL, adjusted for RS, increased overall for preemptive and dialyzed kidney transplant patients after transplantation. RS may reflect differing adaptation processes following KT.

Evaluation of the link between the Guttman errors and response shift at the individual level.

PURPOSE: Methods for response shift (RS) detection at the individual level could be of great interest when analyzing changes in patient-reported outcome data. Guttman errors (GEs), which measure discrepancies in respondents' answers compared to the average sample responses, might be useful for detecting RS at the individual level between two time points, as RS may induce an increase in the number of discrepancies over time. This study aims to establish the link between recalibration RS and the change in the number of GEs over time (denoted index [Formula: see text]) via simulations and explores the discriminating ability of this index. METHODS: We simulated the responses of individuals affected or not affected by recalibration RS (defined as changes in the patients' standard of measurement) to determine whether simulated individuals with recalibration had a greater change in the number of GEs over time than individuals without recalibration. The effects of factors related to the sample, the questionnaire structure and recalibration were investigated. As an illustrative example, the change in the number of GEs was computed in patients suffering from eating disorders. RESULTS: Within simulations, simulated individuals affected by recalibration had, on average, a greater change in the number of GEs over time than did individuals without RS. Some of the parameters related to the questionnaire structure and recalibration magnitude appeared to have substantial effects on the values of [Formula: see text]. Discriminating abilities appeared, however, globally low. CONCLUSION: Some evidence of the link between recalibration and the change in GEs was found in this study. GEs could be a valuable nonparametric tool for RS detection at a more individual level, but further investigation is needed.

The use of proxies and proxy-reported measures: a report of the international society for quality of life research (ISOQOL) proxy task force.

AIMS: Proxy reports are often used when patients are unable to self-report. It is unclear how proxy measures are currently in use in adult health care and research settings. We aimed to describe how proxy reports are used in these settings, including the use of measures developed specifically for proxy reporting in adult health populations. METHODS: We systematically searched Medline, PsycINFO, PsycTESTS, CINAHL and EMBASE from database inception to February 2018. Search terms included a combination of terms for quality of life and health outcomes, proxy-reporters, and health condition terms. The data extracted included clinical context, the name of the proxy measure(s) used and other descriptive data. We determined whether the measures were developed specifically for proxy use or were existing measures adapted for proxy use. RESULTS: The database search identified 17,677 possible articles, from which 14,098 abstracts were reviewed. Of these, 11,763 were excluded and 2335 articles were reviewed in full, with 880 included for data extraction. The most common clinical settings were dementia (30%), geriatrics (15%) and cancer (13%). A majority of articles (51%) were paired studies with proxy and patient responses for the same person on the same measure. Most paired studies (77%) were concordance studies comparing patient and proxy responses on these measures. DISCUSSION: Most published research using proxies has focused on proxy-patient concordance. Relatively few measures used in research with proxies were specifically developed for proxy use. Future work is needed to examine the performance of measures specifically developed for proxies. SYSTEMATIC REVIEW REGISTRATION: PROSPERO No. CRD42018103179.