A discrete choice model implementing gist-based categorization of alternatives, with applications to patient preferences for cancer screening and treatment.

The rational microeconomic decision model is hard-coded into usual econometric specifications such as the Multinomial Logit and Probit models, inter alia. There is a very tight link between utility maximization and the apparatus of welfare theory that underlies economic policy analysis, which creates a tension around the possibility of representing other decision rules. We propose a less restrictive model of choice, built on the concept of gist-based categorization judgments that are assumed to precede (thus, condition) the maximization-driven selection process in decision making. This categorization facilitates decision making by allowing adoption of certain simpler decision rules under appropriate conditions, the drivers of which are endogenously determined. We demonstrate that the proposed model provides better fit than traditional choice models, using cancer screening and treatment choice data from two discrete choice experiments. In addition, we show that the model provides a deeper, more nuanced and insightful perspective on (healthcare) decision making.

Patients' preferences for treatment after neoadjuvant chemoradiotherapy for oesophageal cancer.

BACKGROUND: After neoadjuvant chemoradiotherapy (nCRT) plus surgery for oesophageal cancer, 29 per cent of patients have a pathologically complete response in the resection specimen. Active surveillance after nCRT (instead of standard oesophagectomy) may improve health-related quality of life (HRQoL), but patients need to undergo frequent diagnostic tests and it is unknown whether survival is worse than that after standard oesophagectomy. Factors that influence patients' preferences, and trade-offs that patients are willing to make in their choice between surgery and active surveillance were investigated here. METHODS: A prospective discrete-choice experiment was conducted. Patients with oesophageal cancer completed questionnaires 4-6 weeks after nCRT, before surgery. Patients' preferences were quantified using scenarios based on five aspects: 5-year overall survival, short-term HRQoL, long-term HRQoL, the risk that oesophagectomy is still necessary, and the frequency of clinical examinations using endoscopy and PET-CT. Panel latent class analysis was used. RESULTS: Some 100 of 104 patients (96·2 per cent) responded. All aspects, except the frequency of clinical examinations, influenced patients' preferences. Five-year overall survival, the chance that oesophagectomy is still necessary and long-term HRQoL were the most important attributes. On average, based on calculation of the indifference point between standard surgery and active surveillance, patients were willing to trade off 16 per cent 5-year overall survival to reduce the risk that oesophagectomy is necessary from 100 per cent (standard surgery) to 35 per cent (active surveillance). CONCLUSION: Patients are willing to trade off substantial 5-year survival to achieve a reduction in the risk that oesophagectomy is necessary.

Surveillance in patients with long-segment Barrett's oesophagus: a cost-effectiveness analysis.

OBJECTIVE: Surveillance is recommended for Barrett's oesophagus (BO) to detect early oesophageal adenocarcinoma (OAC). The aim of this study was to evaluate the cost-effectiveness of surveillance. DESIGN: We included 714 patients with long-segment BO in a multicentre prospective cohort study and used a multistate Markov model to calculate progression rates from no dysplasia (ND) to low-grade dysplasia (LGD), high-grade dysplasia (HGD) and OAC. Progression rates were incorporated in a decision-analytic model, including costs and quality of life data. We evaluated different surveillance intervals for ND and LGD, endoscopic mucosal resection (EMR), radiofrequency ablation (RFA) and oesophagectomy for HGD or early OAC and oesophagectomy for advanced OAC. The incremental cost-effectiveness ratio (ICER) was calculated in costs per quality-adjusted life-year (QALY). RESULTS: The annual progression rate was 2% for ND to LGD, 4% for LGD to HGD or early OAC and 25% for HGD or early OAC to advanced OAC. Surveillance every 5 or 4 years with RFA for HGD or early OAC and oesophagectomy for advanced OAC had ICERs of €5.283 and €62.619 per QALY for ND. Surveillance every five to one year had ICERs of €4.922, €30.067, €32.531, €41.499 and €75.601 per QALY for LGD. EMR prior to RFA was slightly more expensive, but important for tumour staging. CONCLUSIONS: Based on a Dutch healthcare perspective and assuming a willingness-to-pay threshold of €35.000 per QALY, surveillance with EMR and RFA for HGD or early OAC, and oesophagectomy for advanced OAC is cost-effective every 5 years for ND and every 3 years for LGD.

Patients' and urologists' preferences for prostate cancer treatment: a discrete choice experiment.

BACKGROUND: Patients' preferences are important for shared decision making. Therefore, we investigated patients' and urologists' preferences for treatment alternatives for early prostate cancer (PC). METHODS: A discrete choice experiment was conducted among 150 patients who were waiting for their biopsy results, and 150 urologists. Regression analysis was used to determine patients' and urologists' stated preferences using scenarios based on PC treatment modality (radiotherapy, surgery, and active surveillance (AS)), and risks of urinary incontinence and erectile dysfunction. RESULTS: The response rate was 110 out of 150 (73%) for patients and 50 out of 150 (33%) for urologists. Risk of urinary incontinence was an important determinant of both patients' and urologists' stated preferences for PC treatment (P<0.05). Treatment modality also influenced patients' stated preferences (P<0.05), whereas the risk of erectile dysfunction due to radiotherapy was mainly important to urologists (P<0.05). Both patients and urologists preferred AS to radical treatment, with the exception of patients with anxious/depressed feelings who preferred radical treatment to AS. CONCLUSION: Although patients and urologists generally may prefer similar treatments for PC, they showed different trade-offs between various specific treatment aspects. This implies that urologists need to be aware of potential differences compared with the patient's perspective on treatment decisions in shared decision making on PC treatment.

Men's preferences for prostate cancer screening: a discrete choice experiment.

BACKGROUND: Screening for prostate cancer (PC) may save lives, but overdiagnosis and overtreatment are serious drawbacks. We aimed to determine men's preferences for PC screening, and to elicit the trade-offs they make. METHODS: A discrete choice experiment (DCE) was conducted among a population-based random sample of 1000 elderly men (55-75-years-old). Trade-offs were quantified with a panel latent class model between five PC screening aspects: risk reduction of PC-related death, screening interval, risk of unnecessary biopsies, risk of unnecessary treatments, and out-of-pocket costs. RESULTS: The response rate was 46% (459/1000). Men were willing to trade-off 2.0% (CI: 1.6%-2.4%) or 1.8% (CI: 1.3%-2.3%) risk reduction of PC-related death to decrease their risk of unnecessary treatment or biopsy with 10%, respectively. They were willing to pay €188 per year (CI: €141-€258) to reduce their relative risk of PC-related death with 10%. Preference heterogeneity was substantial, with men with higher educational levels having a lower probability to opt for PC screening than men with lower educational levels. CONCLUSION: Men were willing to trade-off some risk reduction of PC-related death to be relieved of the burden of biopsies or unnecessary treatments. Increasing knowledge on overdiagnosis and overtreatment, especially for men with lower educational levels, is warranted to prevent unrealistic expectations from PC screening.

Salpingotomy or salpingectomy in tubal ectopic pregnancy: what do women prefer?

There is an ongoing debate whether tubal ectopic pregnancy should be treated by salpingotomy or salpingectomy. It is unknown which treatment women prefer in view of the potentially better fertility outcome but disadvantages of salpingotomy. This study investigated women surgically treated for tubal ectopic pregnancy and subfertile women desiring pregnancy and their preferences for salpingotomy relative to salpingectomy by means of a web-based discrete choice experiment consisting of 16 choice sets. Scenarios representing salpingotomy differed in three attributes: intrauterine pregnancy (IUP) chance, risk of persistent trophoblast and risk of repeat ectopic pregnancy. An 'opt out' alternative, representing salpingectomy, was similar for every choice set. A multinomial logistic regression model was used to analyse relative importance of the attributes. This study showed that the negative effect of repeat ectopic pregnancy was 1.6 times stronger on the preference of women compared with the positive effect of the spontaneous IUP rate. For all women, the risk of persistent trophoblast was acceptable if compensated by a small rise in the spontaneous IUP rate. The conclusion was that women preferred avoiding a repeat ectopic pregnancy to a higher probability of a spontaneous IUP in the surgical treatment of tubal ectopic pregnancy. An ectopic pregnancy occurs when a fertilized egg gets stuck inside the Fallopian tube where it starts growing instead of passing on to the uterus. This may lead to serious problems, such as internal bleeding and pain. Therefore, in the majority of women, it is necessary to remove the ectopic pregnancy by means of an operation. Two types of surgery are being used in removing the ectopic pregnancy. A conservative approach, salpingotomy, preserves the tube but bears the risk of incomplete removal of the pregnancy tissue (persistent trophoblast), which then needs additional treatment, and of a repeat ectopic pregnancy in the same tube in the future. A radical approach, salpingectomy, bears no risk of persistent trophoblast and limits the risk of repeat tubal pregnancy, but leaves only one tube for reproductive capacity. It is unknown which type of operation is better, especially for future fertility. We investigated women's preferences between these two treatments for ectopic pregnancy, i.e. does a better fertility prognosis outweigh the potential disadvantages of persistent trophoblast and an increased risk for ectopic pregnancy in the future? The study results show in the surgical treatment of tubal ectopic pregnancy that women preferred avoiding a repeat ectopic pregnancy to gaining a higher chance of a spontaneous intrauterine pregnancy. The risk of additional treatment in the case of persistent trophoblast after salpingotomy was acceptable if compensated by a small rise in intrauterine pregnancy rate.

Preferences for colorectal cancer screening strategies: a discrete choice experiment.

BACKGROUND: Guidelines underline the role of individual preferences in the selection of a screening test, as insufficient evidence is available to recommend one screening test over another. We conducted a study to determine the preferences of individuals and to predict uptake for colorectal cancer (CRC) screening programmes using various screening tests. METHODS: A discrete choice experiment (DCE) questionnaire was distributed among naive subjects, yet to be screened, and previously screened subjects, aged 50-75 years. Subjects were asked to choose between scenarios on the basis of faecal occult blood test (FOBT), flexible sigmoidoscopy (FS), total colonoscopy (TC) with various test-specific screening intervals and mortality reductions, and no screening (opt-out). RESULTS: In total, 489 out of 1498 (33%) screening-naïve subjects (52% male; mean age+/-s.d. 61+/-7 years) and 545 out of 769 (71%) previously screened subjects (52% male; mean age+/-s.d. 61+/-6 years) returned the questionnaire. The type of screening test, screening interval, and risk reduction of CRC-related mortality influenced subjects' preferences (all P<0.05). Screening-naive and previously screened subjects equally preferred 5-yearly FS and 10-yearly TC (P=0.24; P=0.11), but favoured both strategies to annual FOBT screening (all P-values <0.001) if, based on the literature, realistic risk reduction of CRC-related mortality was applied. Screening-naive and previously screened subjects were willing to undergo a 10-yearly TC instead of a 5-yearly FS to obtain an additional risk reduction of CRC-related mortality of 45% (P<0.001). CONCLUSION: These data provide insight into the extent by which interval and risk reduction of CRC-related mortality affect preferences for CRC screening tests. Assuming realistic test characteristics, subjects in the target population preferred endoscopic screening over FOBT screening, partly, due to the more favourable risk reduction of CRC-related mortality by endoscopy screening. Increasing the knowledge of potential screenees regarding risk reduction by different screening strategies is, therefore, warranted to prevent unrealistic expectations and to optimise informed choice.

What determines individuals' preferences for colorectal cancer screening programmes? A discrete choice experiment.

INTRODUCTION: In many countries uptake of colorectal cancer (CRC) screening remains low. AIM: To assess how procedural characteristics of CRC screening programmes determine preferences for participation and how individuals weigh these against the perceived benefits from participation in CRC screening. METHODS: A discrete choice experiment was conducted among subjects in the age group of 50-75 years, including both screening-naïve subjects and participants of a CRC screening programme. Subjects were asked on their preferences for aspects of CRC screening programmes using scenarios based on pain, risk of complications, screening location, preparation, duration of procedure, screening interval and risk reduction of CRC-related death. RESULTS: The response was 31% (156/500) for screening-naïve and 57% (124/210) for CRC screening participants. All aspects proved to significantly influence the respondents' preferences. For both groups combined, respondents required an additional relative risk reduction of CRC-related death by a screening programme of 1% for every additional 10 min of duration, 5% in order to expose themselves to a small risk of complications, 10% to accept mild pain, 10% to undergo preparation with an enema, 12% to use 0.75l of oral preparation combined with 12h fasting and 32% to use an extensive bowel preparation. Screening intervals shorter than 10 years were significantly preferred to a 10-year screening interval. CONCLUSION: This study shows that especially type of bowel preparation, risk reduction of CRC related death and length of screening interval influence CRC screening preferences. Furthermore, improving awareness on CRC mortality reduction by CRC screening may increase uptake.

Evaluation of testicular biopsies for carcinoma in situ: immunohistochemistry is mandatory.

Carcinoma in situ (CIS) is the common precursor of all type II testicular germ cell tumors (TGCTs), i.e. seminomas and non-seminomas, which can be diagnosed using a surgical biopsy. The objective of this study was to investigate the additional value of immunohistochemistry for the diagnosis of CIS in assessing testicular biopsies taken in the context of infertility. A series of 21 infertile patients were retrieved from the Dutch pathological database (PALGA), being diagnosed with an invasive TGCT, while a matched previously obtained testicular biopsy was diagnosed as non-malignant. From 20 patients, both the invasive tumors as well as the biopsies were revised using morphology and immunohistochemistry for OCT3/4, placental-like alkaline phosphatase and c-KIT, all known established markers for CIS. The presence of CIS or invasive malignancies was scored. There are no interventions. Morphological criteria alone allowed an experienced pathologist in TGCTs to diagnose CIS in five and an invasive tumor in two cases (total n = 7, 35%). Application of immunohistochemistry resulted in the identification of an additional four cases of CIS (total n = 11, 55%, additional value of 20%). The initial correct diagnosis of CIS could have prevented a second gonadectomy in four patients (20%). This study, for the first time, really shows that time of progression from CIS to seminoma is longer than to non-seminoma. Our study demonstrates that immunohistochemistry should be performed for the diagnosis of CIS of the testis on single biopsies obtained because of infertility, resulting in an extra diagnostic yield of at least 20%. Application of this protocol will allow early diagnosis, and therefore prevent any adverse anti-cancer treatment sequelae including gonadectomy, and requiring life long androgen supplementation in some patients.