Kidney trajectory charts to assist general practitioners in the assessment of patients with reduced kidney function: a randomised vignette study

ObjectiveTo investigate the decisional impact of an age-based chart of kidney function decline to support general practitioners (GPs) to appropriately interpret estimated glomerular filtration rate (eGFR) and identify patients with a clinically relevant kidney problem.Design and settingRandomised vignette studyParticipants372 Australian GPs from August 2018 to November 2018.InterventionGPs were given two patient case scenarios: (1) an older woman with reduced but stable renal function and (2) a younger Aboriginal man with declining kidney function still in the normal range. One group was given an age-based chart of kidney function to assist their assessment of the patient (initial chart group); the second group was asked to assess the patients without the chart, and then again using the chart (delayed chart group).Main outcome measuresGPs’ assessment of the likelihood—on a Likert scale—that the patients had chronic kidney disease (CKD) according to the usual definition or a clinical problem with their kidneys.ResultsPrior to viewing the age-based chart GPs were evenly distributed as to whether they thought case 1—the older woman—had CKD or a clinically relevant kidney problem. GPs who had initial access to the chart were less likely to think that the older woman had CKD, and less likely to think she had a clinically relevant problem with her kidneys than GPs who had not viewed the chart. After subsequently viewing the chart, 14% of GPs in the delayed chart group changed their opinion, to indicate she was unlikely to have a clinically relevant problem with her kidneys.Prior to viewing the chart, the majority of GPs (66%) thought case 2—the younger man—did not have CKD, and were evenly distributed as to whether they thought he had a clinically relevant kidney problem. In contrast, GPs who had initial access to the chart were more likely to think he had CKD and the majority (72%) thought he had a clinically relevant kidney problem. After subsequently viewing the chart, 37% of GPs in the delayed chart group changed their opinion to indicate he likely had a clinically relevant problem with his kidneys.ConclusionsUse of the chart changed GPs interpretation of eGFR, with increased recognition of the younger male patient’s clinically relevant kidney problem, and increased numbers classifying the older female patient’s kidney function as normal for her age. This study has shown the potential of an age-based kidney function chart to reduce both overdiagnosis and underdiagnosis.

Eliciting health state utilities for Aromatic L-amino Acid Decarboxylase (AADC) deficiency: a UK vignette study

Purpose The aim of this study was to generate health state utilities for aromatic L-amino acid decarboxylase (AADC) deficiency, a rare genetic, lifelong neurogenerative condition predominantly manifesting in young infants. Methods Participants were presented with health state vignettes. These had been previously developed based on published literature, clinician input, interviews with parents of AADC deficiency patients and expert opinion. A total of 5 health state vignettes were presented: bedridden, head control, sitting unsupported, standing with assistance and walking with assistance. Health state utilities (HSU) were elicited using time-trade off (TTO; 10-year time horizon) and the standard gamble (SG). The vignettes were completed online by panel participants drawn from a representative sample of the United Kingdom residential population. Results A total of 1598 participants completed the vignettes. Around 21% had incongruent responses (higher utilities for the bedridden compared to walking health states). Incongruent responses were associated with shorter task completion times, gender and parental status. These responses were removed from the analysis. Health state utilities (HSU) increased correspondingly as health states improved for both the TTO and SG. The mean HSU (standard deviation) for the TTO task were: bedridden state 0.49 (0.34); head control 0.54 (0.33), sitting unsupported 0.63 (0.31); standing with assistance 0.68 (0.31); and walking with assistance 0.73 (0.31). For the SG, mean health state utilities were: 0.56 (0.28), 0.57 (0.27), 0.67 (0.24), 0.70 (0.24), and 0.75 (0.25), respectively. Conclusion Health state utilities were derived for AADC deficiency through a vignette study. These will be used for a cost-effectiveness model of an AADC deficiency treatment.

How Does Communicating Herd Immunity Affect Immunization Intentions?

While previous studies have shown that communicating herd immunity can increase immunization intentions, it is unclear how the definition of the beneficiaries influences intentions. In a vignette study, using a new hypothetical influenza virus, 4,172 participants from five European countries (Bulgaria, N=873; Denmark, N=896; England, N=873; Estonia, N=916; and Italy, N=745) were randomized to one of three experimental conditions: (1) control (no mention of herd immunity), (2) society (social benefit of immunization for overall society mentioned), and (3) friends (social benefit for friends and family members mentioned). While the study did not find that communicating herd immunity influenced overall immunization intentions across the five countries, it found substantial cross-country differences in the effect of the communication. In England, friends increased intentions, while society increased intentions in Denmark but decreased it in Italy. While communicating the social benefit of immunization can influence intentions, its contrasting effects highlight the importance of empirically testing.