The effect of different graphical and numerical likelihood formats on perception of likelihood and choice.

BACKGROUND: Quantitative risk information plays an important role in decision making about health. This study focuses on commonly used numerical and graphical formats and examines their effect on perception of different likelihoods and choice preferences. METHODS: An experimental study was conducted with 192 participants, who evaluated 2 sets of 4 lotteries. Numerical formats to describe likelihood varied systematically between participants (X%, X-in-100, or 1-in-X). The effect of graphic formats (bar charts, icon charts) was assessed as a within-subjects factor. Dependent measures included perceived likelihood, choice preferences about participating in the lottery, and processing times. RESULTS: Numerical likelihoods presented as 1-in-X were processed fastest and were perceived as conveying larger likelihoods than the X-in-100 and percentages formats (mean response times in seconds: 5.65 v. 7.31 and 6.50; mean rating on a 1-9 scale: 4.38 v. 3.30 and 3.31, respectively). The 1-in-X format also evoked a stronger willingness to participate in a lottery than the 2 other numerical formats. The effect of adding graphs on perceived likelihood was moderated by numerical aptitude. Graphs reduced ratings of perceived likelihood of participants with lower numeracy, while there was no overall effect for participants with higher numeracy. CONCLUSION: Perception of likelihood differs significantly depending on the numerical format used. The 1-in-X format yields higher perceived likelihoods and it appears to be the easiest format to interpret. Graphs primarily affect perception of likelihood of people with lower numerical aptitude. These effects should be taken into account when discussing medical risks with patients.

Risks, trust and knowledge: determinants of pregnant women's decisions regarding participation in a future Q fever screening and treatment program during a large epidemic in The Netherlands.

OBJECTIVE: Contracting Q fever during pregnancy carries a risk of developing obstetric complications. The aim of this study was to gain insight into pregnant women's decisions regarding participation in a future Q fever screening and treatment program. METHODS: Pregnant women (N = 148) in Q fever high-risk areas in The Netherlands were recruited via midwives' practices and via an online panel for a cross-sectional questionnaire survey. The outcome measures included intention to participate in the program, Q fever exposure risk, perceived Q fever risk, trust in health professionals and authorities, disease-related knowledge and additional outcome measures. RESULTS: Fifty-six percent of the respondents intended to participate in the screening and treatment program. The sole determinant of a higher intended program uptake was a more positive appraisal of program efficacy and convenience. This appraisal was in turn associated with perceived risk and knowledge. CONCLUSION: Women's appraisal of program efficacy and convenience, their disease-related knowledge and perceived Q fever risk seem to be crucial for their intended program uptake. A successful implementation of a Q fever screening and treatment program may thus depend on the benefits and downsides of the program, and on securing that women are aware of the risks of the disease.

Waiting for elective surgery: effect on physical problems and postoperative recovery.

BACKGROUND: Long waiting times for elective surgery pose a threat to the quality of care. Our study aimed to assess (i) the physical symptoms and disabilities patients experience during the wait, (ii) the perceived improvements after surgery and (iii) whether problems increase during the wait or longer waits affect postoperative outcomes. METHODS: A cross-sectional questionnaire study with postoperative follow up was held among patients waiting for surgery of varicose veins (n = 176), inguinal hernia (n = 201) and gallstones (n = 128) in 27 hospitals. RESULTS: During the wait, each group reported increased levels of pain and impaired mobility (Nottingham Health Profile, P < 0.05). However, 15-41% of patients had no or mild symptoms, whereas 5% of inguinal hernia patients had severe pain and 17% of gallstone patients reported >or=1 colic attacks per week. Surgery resolved symptoms in 86-95% of patients. The length of the wait was not associated with problems during the wait or with postoperative outcomes (multilevel regression analysis, P > 0.01). CONCLUSIONS: Waiting for general surgery primarily prolongs the suffering from symptoms, which are relieved by surgery. Although the prioritization of patients with more severe symptoms would reduce the overall burden of waiting, patients with minimal symptoms may be advised to refrain from surgery.

The acceptability of waiting times for elective general surgery and the appropriateness of prioritising patients.

BACKGROUND: Problematic waiting lists in public health care threaten the equity and timeliness of care provision in several countries. This study assesses different stakeholders' views on the acceptability of waiting lists in health care, their preferences for priority care of patients, and their judgements on acceptable waiting times for surgical patients. METHODS: A questionnaire survey was conducted among 257 former patients (82 with varicose veins, 86 with inguinal hernia, and 89 with gallstones), 101 surgeons, 95 occupational physicians, and 65 GPs. Judgements on acceptable waiting times were assessed using vignettes of patients with varicose veins, inguinal hernia, and gallstones. RESULTS: Participants endorsed the prioritisation of patients based on clinical need, but not on ability to benefit. The groups had significantly different opinions (p < 0.05) on the use of non-clinical priority criteria and on the need for uniformity in the prioritisation process. Acceptable waiting times ranged between 2 and 25 weeks depending on the type of disorder (p < 0.001) and the severity of physical and psychosocial problems of patients (p < 0.001). Judgements were similar between the survey groups (p = 0.3) but responses varied considerably within each group depending on the individual's attitude towards waiting lists in health care (p < 0.001). CONCLUSION: The explicit prioritisation of patients seems an accepted means for reducing the overall burden from waiting lists. The disagreement about appropriate prioritisation criteria and the need for uniformity, however, raises concern about equity when implementing prioritisation in daily practice. Single factor waiting time thresholds seem insufficient for securing timely care provision in the presence of long waiting lists as they do not account for the different consequences of waiting between patients.

Prioritising patients on surgical waiting lists: a conjoint analysis study on the priority judgements of patients, surgeons, occupational physicians, and general practitioners.

The prioritisation of patients on waiting lists is ascribed high potential for diminishing the consequences of waiting times for elective surgery. However, consistent evidence is lacking about which factors determine patient priority and it is unclear whether different stakeholders have different opinions on this issue. This study, conducted in the Netherlands, investigates the judgements of patients, laypersons (i.e. patients on other waiting lists), and physicians on the priority of patients on waiting lists. Participants were former patients with varicose veins (N=82), inguinal hernia (N=86), and gallstones (N=89), 101 surgeons, 95 occupational physicians, and 65 general practitioners. Each participant judged the priority of paper vignettes of patients with varicose veins, inguinal hernia, and gallstones. The vignettes were designed according to conjoint analysis methodology and described the physical symptoms, the psychological distress, the social limitations, and impairments in work of patients. Multilevel regression analysis of the responses showed that all groups made significant distinctions in patient priority depending on the severity of each characteristic in the vignettes. The physical symptoms and impairments in work had on average the highest impact on priority, but the summed impact of non-physical factors exceeded that of the physical symptoms. The different groups of participants appraised only the importance of the physical symptoms differently, but opinions on priority varied widely within each group. Whereas the high level of agreement between the different groups would facilitate the acceptance and the implementation of explicit prioritisation of patients on the waiting list, the high inter-individual variation signifies that consensus criteria for prioritisation are needed to warrant equity and transparency in care provision.

Waiting for elective general surgery: physical, psychological and social consequences.

BACKGROUND: Long surgical waiting lists are common and receive serious consideration. To evaluate the positive and negative effects of waiting lists, insight into the consequences of waiting is needed. The present study aims to assess what insight the current literature provides into the effects of delayed surgery for varicose veins, inguinal hernia in adults, gallstones, and breast cancer in terms of physical, psychological and social aspects. METHODS: Searches of Medline and Embase, for the period January 1985-September 2003, were performed to identify articles providing direct or indirect insight into the consequences of waiting for surgery for each disorder. Reference lists of retrieved reports were examined for relevant articles. RESULTS: Seven studies were identified with direct data on consequences of delay in elective surgery. Relevant indirect data were found in 32 reports. Results indicated that delayed varicose vein surgery or inguinal hernia repair involves marginal physical, psychological or social suffering, and that severe deterioration is unlikely. The impact of delayed cholecystectomy seems more profound by suffering on all three health aspects. Complications while waiting do occur, with a higher risk for patients with previous complications. Longer delays for breast cancer surgery seem to adversely affect prognosis, although it is unclear which interval is associated with such an effect. Moreover, having breast cancer undoubtedly affects psychological health. CONCLUSIONS: There is a remarkable paucity of studies addressing the consequential impact of waiting for elective surgery on patients' health for each of the four studied disorders. Current literature permits merely general estimation of this consequential impact. As specific assessment of these consequences is important for daily practice and for policy, further research is required.