A review of measurement of patient preferences for treatment outcomes after prostate cancer

A (Latent) Class of Their Own: Response Patterns in Trading Off Quantity and Quality of Life in Time Trade-Off Exercises

BACKGROUND

Conflicting results regarding associations of time trade-off (TTO) valuations with respondent characteristics have been reported, mostly on the basis of regression analyses. Alternative approaches, such as the latent class analysis (LCA), may add to the further understanding of variations in TTO responses.

OBJECTIVES

To identify whether subgroups of respondents can be identified on the basis of their responses to TTO exercises and to investigate which respondent characteristics are associated with membership of the identified subgroups.

METHODS

Members of the Dutch general public, aged 18 to 65 years, completed a Web-based questionnaire concerning sociodemographic characteristics, three TTO exercises valuing health states described using the domains of the EuroQol five-dimensional questionnaire, and preference for quality versus quantity of life. LCA was used to identify patterns in the responses. Predictive variables were included in the final LCA model to identify the particular respondent characteristics that predict subgroup membership.

RESULTS

The sample consisted of 1067 respondents. Four latent classes were identified in the responses to TTO exercises. Two were high traders, focusing on quality of life and trading off a relatively high number of years. The other two were low traders, focusing on length of life. Predictive analyses revealed significant differences between subgroups in terms of age, sex, subjective life expectancy, and preference for quantity over quality of life.

CONCLUSIONS

We showed that distinct classes of respondents can be discerned in TTO responses from the general public, distinguishing subgroups of low and high traders. More research in this area should confirm our findings and investigate their implications for health state valuation exercises.

Patients' Preferences for the Treatment of Metastatic Castrate-resistant Prostate Cancer: A Discrete Choice Experiment

PURPOSE

Patient treatment preferences are increasingly being used to inform health care decision making. This discrete choice experiment assessed how men perceive the risks and benefits of hypothetical treatment options for metastatic castrate-resistant prostate cancer (mCRPC).

METHODS

Treatment attributes for inclusion were identified through a review of the literature and product labels. Expert interviews confirmed clinical appropriateness and patient relevance of the attributes, which included effectiveness (delay in months before chemotherapy), steroid use, possible drug interactions (additional hospital visits for monitoring), fogginess (effects on cognition and memory), fatigue (extreme tiredness), food restrictions, and bone pain. Following a pilot, the final discrete choice experiment included 18 choice sets presenting treatments for mCRPC and was completed by men with mCRPC in France, Germany, and the United Kingdom. Data were analyzed using a conditional logit model, with odds ratios (ORs) used to indicate preference for attributes, and tradeoff measures (TOM) were estimated using the ratio of coefficients.

FINDINGS

Within each attribute category and with all other factors being equal, participants (N = 285) indicated a strong preference for treatments that fully control bone pain (OR = 12.069 [95% CI, 10.555-13.800]) and for treatments that delay chemotherapy (OR, 1.727 [95% CI, 1.548-1.927]). They also preferred treatments that were associated with the lowest risk of fogginess (OR, 2.115 [95% CI, 1.849-2.420]), a lower risk of fatigue (OR, 1.365 [95% CI 1.219-1.528]), and fewer additional hospital visits (OR, 1.245 [95% CI 1.111-1.397]) than the respective reference categories. Participants preferred to use steroids under advice from a physician (OR, 1.275 [95% CI 1.132-1.437]). Food restrictions related to taking medication were not a significant concern for participants. TOM results indicated that large tradeoffs in effectiveness, fogginess, and fatigue are required for patients to prefer a treatment with uncontrolled bone pain that is very difficult to live with.

IMPLICATIONS

Men with mCRPC consider a wide range of factors when making decisions regarding their treatment. They showed a strong preference for treatment associated with better control of bone pain. They also placed value on treatments that could delay the need for chemotherapy, and they preferred to avoid side effects such as cognition and memory loss, and extreme tiredness. TOMs highlighted the importance of symptom control, even compared with potential side effects. An understanding of the degree to which patients value the attributes associated with various treatment options will assist clinicians and health care professionals when making decisions regarding the management of men with mCRPC.

Factors that influence patient preferences for prostate cancer management options: A systematic review

PURPOSE

We performed a systematic review to evaluate evidence regarding factors that influence patient preferences for management options for localized prostate cancer.

METHODS

We followed a prespecified search protocol (PROSPERO identifier CRD42014009173) to identify studies that evaluated patient preferences for prostate cancer management options for localized prostate cancer. We queried PubMed, the Cochrane Database of Systematic Reviews, Embase, Cumulative Index to Nursing & Allied Health Literature (CINAHL) Plus, and Econ-Lit databases. Two separate reviewers completed the article selection process and review, including coding of study characteristics. Study quality was scored according to the PREFS checklist, which consists of five criteria: Purpose, Respondents, Explanation, Findings, and Significance. Reviewers summarized the primary findings of each article included in the analysis.

RESULTS

Of the 606 citations identified in the literature search, there were a total of 21 articles that met all selection criteria, reporting results for a total of 4,131 subjects. Themes identified in the studies included: the importance of patient perceptions of treatment efficacy and side effects; the influence of physician recommendations on patient decision-making; and the prioritization of concerns regarding treatment side effects among those men who prefer radiation therapy or active surveillance. The articles had an average PREFS score of 3.4 (standard deviation [SD] 1.0), which is similar to a recent study for breast cancer treatment preferences.

CONCLUSION

This systematic review of factors that influence patient preferences for prostate cancer management options identified a small, but high quality, group of articles that satisfied the selection criteria. The available evidence suggests that interventions aimed at informing patients regarding the comparative effectiveness of prostate cancer management alternatives should include the influence of physician recommendations and family members' desires on patient decision-making.

Patient preferences for the treatment of type 2 diabetes: a scoping review

BACKGROUND

As more studies report on patient preferences, techniques are needed to identify, assess and, eventually, synthesize results from a diverse set of methodologies. Data on patient preferences are valuable to decision makers in a variety of ways. Preferences for outcomes can be used to inform decision and cost-effectiveness models, while preferences for treatments can inform patient-centered outcomes research (PCOR) and patient-centered care.

OBJECTIVES

This project sought to identify and assess the literature reporting on the treatment preferences of adult patients with type 2 diabetes. In addition to cataloging the preference elicitation methods used, we developed and assessed a novel quality assessment checklist for preference-based studies.

DATA SOURCES

PubMed, EMBASE, CINAHL, and EconLit databases were searched to identify studies examining patient preferences for medications for type 2 diabetes studies published since inception of each database.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS

The review protocol specified inclusion of studies reporting diabetes-treatment preferences among adults with type 2 diabetes, using a range of preference measurement methods. Studies were excluded if participants were not patients with type 2 diabetes and if treatments were not pharmacological therapies targeting glycemic control, or if no primary preference information was collected. Two investigators independently reviewed titles, abstracts, and articles sequentially to select studies for data abstraction based on the inclusion and exclusion criteria. Disagreements were resolved by consensus.

STUDY APPRAISAL AND SYNTHESIS METHODS

Data on study country, year, number of respondents, preference elicitation method, number of attributes, subgroup analyses, and funding source were abstracted into standardized tables. A novel checklist (PREFS) was used to assess the data quality and validity across different types of preference studies by assessing the following: purpose of the study; respondent sampling; explanation of preference assessment methods; findings reported for total sample; and significance testing. Each item was scored, and an aggregate score was then calculated (ranging from 0 to 5).

RESULTS

Of the 2,100 unique citations, 61 met the inclusion criteria. The studies used conjoint analysis (n = 10), time trade-off (n = 6), standard gamble (n = 2), contingent valuation (n = 1), other stated preference methods (n = 39), and revealed preferences (n = 5). Sample sizes ranged from 27 to 14,033, with an average of 562 respondents, and two-thirds included a subgroup analysis. Most studies were conducted in one country, predominantly the USA (n = 27), UK (n = 14), Canada (n = 10), and Germany (n = 7), while 14 were conducted in multiple (2-18) countries across two or more countries. There was an increase in the annual rate of studies published over time from the time of the first publication in 1985 (p = < 0.01). Most (n = 52) studies were funded by pharmaceutical or device companies, with government, academic, association, and hospital sources also funding studies. One study met all five of the PREFS criteria and 12 met four; yet four studies met none of the criteria. The average was 27.

LIMITATIONS

Currently, preferences reviews are limited by the mixed quality in the reporting of studies, the publication bias inherent in the literature, a lack of guidelines to conduct various methods, and the difficulty of synthesizing results from different studies. Our study is also limited by its focus on English language articles.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

This study provides the first systematic evaluation of the methods used in the broad existing body of research into patient preferences for type 2 diabetes medications and can serve as a primary source of information for decision makers. Future work is necessary to assess the utility of the results of reviews of preference information and to develop best-practice guidelines for the reporting of, and methods of conducting, preference studies and systematic reviews of such studies.

REGISTRATION

This systematic review was registered with PROSPERO (registration number CRD42012002285).

Survival gains needed to offset persistent adverse treatment effects in localised prostate cancer

Background:

Men diagnosed with localised prostate cancer (LPC) face difficult choices between treatment options that can cause persistent problems with sexual, urinary and bowel function. Controlled trial evidence about the survival benefits of the full range of treatment alternatives is limited, and patients' views on the survival gains that might justify these problems have not been quantified.

Methods:

A discrete choice experiment (DCE) was administered in a random subsample (n=357, stratified by treatment) of a population-based sample (n=1381) of men, recurrence-free 3 years after diagnosis of LPC, and 65 age-matched controls (without prostate cancer). Survival gains needed to justify persistent problems were estimated by substituting side effect and survival parameters from the DCE into an equation for compensating variation (adapted from welfare economics).

Results:

Median (2.5, 97.5 centiles) survival benefits needed to justify severe erectile dysfunction and severe loss of libido were 4.0 (3.4, 4.6) and 5.0 (4.9, 5.2) months. These problems were common, particularly after androgen deprivation therapy (ADT): 40 and 41% overall (n=1381) and 88 and 78% in the ADT group (n=33). Urinary leakage (most prevalent after radical prostatectomy (n=839, mild 41%, severe 18%)) needed 4.2 (4.1, 4.3) and 27.7 (26.9, 28.5) months survival benefit, respectively. Mild bowel problems (most prevalent (30%) after external beam radiotherapy (n=106)) needed 6.2 (6.1, 6.4) months survival benefit.

Conclusion:

Emerging evidence about survival benefits can be assessed against these patient-based benchmarks. Considerable variation in trade-offs among individuals underlines the need to inform patients of long-term consequences and incorporate patient preferences into treatment decisions.

Latent class cluster analysis to understand heterogeneity in prostate cancer treatment utilities

Background

Men with prostate cancer are often challenged to choose between conservative management and a range of available treatment options each carrying varying risks and benefits. The trade-offs are between an improved life-expectancy with treatment accompanied by important risks such as urinary incontinence and erectile dysfunction. Previous studies of preference elicitation for prostate cancer treatment have found considerable heterogeneity in individuals' preferences for health states given similar treatments and clinical risks.

Methods

Using latent class mixture model (LCA), we first sought to understand if there are unique patterns of heterogeneity or subgroups of individuals based on their prostate cancer treatment utilities (calculated time trade-off utilities for various health states) and if such unique subgroups exist, what demographic and urological variables may predict membership in these subgroups.

Results

The sample (N = 244) included men with prostate cancer (n = 188) and men at-risk for disease (n = 56). The sample was predominantly white (77%), with mean age of 60 years (SD ± 9.5). Most (85.9%) were married or living with a significant other. Using LCA, a three class solution yielded the best model evidenced by the smallest Bayesian Information Criterion (BIC), substantial reduction in BIC from a 2-class solution, and Lo-Mendell-Rubin significance of < .001. The three identified clusters were named high-traders (n = 31), low-traders (n = 116), and no-traders (n = 97). High-traders were more likely to trade survival time associated with treatment to avoid potential risks of treatment. Low-traders were less likely to trade survival time and accepted risks of treatment. The no-traders were likely to make no trade-offs in any direction favouring the status quo. There was significant difference among the clusters in the importance of sexual activity (Pearson's χ² = 16.55, P = 0.002; Goodman and Kruskal tau = 0.039, P < 0.001). In multinomial logistic regression, the level of importance assigned to sexual activity remained an independent predictor of class membership. Age and prostate cancer/at-risk status were not significant factors in the multinomial model.

Conclusion

Most existing utility work is undertaken focusing on how people choose on average. Distinct clusters of prostate cancer treatment utilities in our sample point to the need for further understanding of subgroups and need for tailored assessment and interventions.

Measuring patient preference and surgeon choice

One of the major barriers to randomized trials in the field of surgery is the presence of strong preferences for one of the treatment options. Patients and surgeons who favor strongly a particular treatment approach are usually reluctant to participate in trials where operative intervention is determined on the basis of randomization. This then affects both the feasibility of the trial in terms of achieving the required sample size as well as the generalizability of the study's findings. Therefore, measurement of patient and surgeon preference is a crucial component of the feasibility assessment for surgery trials. In this article, we introduce the Prospective Measure of Preference, which is a novel method to measure preferences that has been designed to accommodate the complexity of surgical decision-making. We also present a simple method to measure individual and community equipoise among expert clinicians to assess the feasibility of future randomized trials in surgery.

Early Prostate Cancer: Hedonic Prices Model of Provider–Patient Interactions and Decisions

PURPOSE

To determine the relative influence of treatment features and treatment availabilities on final treatment decisions in early prostate cancer.

METHODS AND MATERIALS

We describe and apply a model, based on hedonic prices, to understand provider-patient interactions in prostate cancer. This model included four treatments (observation, external beam radiotherapy, brachytherapy, and prostatectomy) and five treatment features (one efficacy and four treatment complication features). We performed a literature search to estimate (1) the intersections of the "bid" functions and "offer" functions with the price function along different treatment feature axes, and (2) the treatments actually rendered in different patient subgroups based on age. We performed regressions to determine the relative weight of each feature in the overall interaction and the relative availability of each treatment modality to explain differences between observed vs. predicted use of different modalities in different patient subpopulations.

RESULTS

Treatment efficacy and potency preservation are the major factors influencing decisions for young patients, whereas preservation of urinary and rectal function is much more important for very elderly patients. Referral patterns seem to be responsible for most of the deviations of observed use of different treatments from those predicted by idealized provider-patient interactions. Specifically, prostatectomy is used far more commonly in young patients and radiotherapy and observation used far more commonly in elderly patients than predicted by a uniform referral pattern.

CONCLUSIONS

The hedonic prices approach facilitated identifying the relative importance of treatment features and quantification of the impact of the prevailing referral pattern on prostate cancer treatment decisions.

Prostate cancer, the PSA test and academic detailing in Australian general practice: an economic evaluation

OBJECTIVES

To evaluate whether introduction of a national education program for GPs to improve decision making relating to the use of prostate specific antigen (PSA) testing for screening represents 'value-for-money' from the perspective of the Australian Government.

METHODS

The annual equivalent costs and consequences of a proposed national program in steady state operation are estimated for Australia using 1996 as the reference year. Because of the controversy about the efficacy of screening using PSA testing, two scenarios are modelled. Uncertainty in the model is examined using Monte Carlo simulation methods.

RESULTS

In scenario one, our model predicts that the national program would cost dollars 12.5 million (gross) or dollars 6.6 million (net), would reduce the burden of disease by 4.7% of total DALYs due to prostate cancer in those aged 70 and over, with no loss of life and an incremental cost effectiveness ratio (ICER) of dollars 16,000/DALY (gross) and dollars 8,500/DALY (net). In scenario two, the proposed program would cost dollars 12.5 million (gross) or dollars 7.1 million (net), would reduce the burden of disease by 3.1% of total, increase by 44 the prostate cancer deaths at an ICER of dollars 24,000/DALY (gross) and dollars 14,000/DALY (net).

CONCLUSIONS

These findings, with an overall health benefit at moderate cost and acceptable ICER, support the case for consideration of a national education program on the assumption that prostate cancer screening over age 70 does not reduce mortality. A larger Australian study currently being conducted should provide stronger evidence on the value of implementing a full national program.

Radical Prostatectomy: Which Quality of Life?

The aim of the present study was to evaluate quality of life in patients submitted to radical prostatectomy, by correlating the results of the post-operative condition with follow-up data at 6 and 12 months.

Materials and Methods.

Between october 2004 and december 2005, 68 patients - mean age 68 (range 49–76) - treated with radical retropubic prostatectomy for localized prostate cancer (T2a, T2b, No, Mo) were consecutively enrolled onto the study. All patients underwent sexual as well as urinary incontinence rehabilitation, showing good compliance. We evaluated quality of life before prostatectomy (T0), 6 (T1) and 12 (T2) months after surgery through the Short Form 36 questionnaire, for which an analysis of variance for repeated measures was carried out. Patients were interviewed by our department psychologist regarding urinary incontinence and erectile dysfunction. All patients were disease-free at the time of evaluation.

Results.

No significant differences were observed between physical and mental health indices. Conversely, a significant improvement (p<0.001) was seen in all SF-36-questionnaire 8 scales, comparing preoperative T0 values with T1 and T2 values. Of the 68 patients, 53 (78%) no longer needed pads at the T2 follow-up, while 15 (22%) reported using 3–4 pads/day A significant worsening of the sexual function (maintenance of erection) was observed in 51 (75%) patients, who had reported having normal sexual activity preoperatively (T0). On the other hand, 17 (25%) patients reported having an adequate erection to engage in sexual intercourse.

Conclusions.

Despite the differences observed in physical and mental health scores during the three periods evaluated (T0, T1 and T2), overall quality of life does not appear to have been greatly compromised by surgery. At T2 follow-up, in fact, all 68 patients reported to be satisfied with having undergone radical prostatectomy because of its benefits in terms of survival and its limited effects on their quality of life. (Urologia 2007; 74: 22–9)

Assessment of patient concern and adequacy of informed consent regarding infertility resulting from prostate cancer treatment

OBJECTIVES

To address in a questionnaire-based study the frequency at which fertility is a concern for men when they consider their prostate cancer treatment options. A secondary aim was to assess the rate at which men were informed of the fertility implications of prostate cancer treatment by their physician before their selection of a treatment option.

METHODS

Two questionnaires were used. One questionnaire was distributed to men with localized prostate cancer who had undergone treatment within the past year. These questions addressed whether continence, erectile function, and fertility were discussed with them by their physician during the prostate cancer treatment selection process. The second questionnaire was distributed to men with newly diagnosed prostate cancer and queried their level of concern about the effects of prostate cancer treatment on sexual function, urinary function, and fertility.

RESULTS

All patients receiving the first questionnaire stated that they were informed of the incontinence and impotence side effects of prostate cancer treatments, but only 8.7% stated that they were informed of the effect that prostate cancer treatments would have on their future fertility. Of the patients completing the second questionnaire, 53.7% responded that incontinence was the side effect of prostate cancer treatment that caused them the most concern, 42.6% stated that erectile dysfunction was the most concerning, and 3.7% listed fertility as the major concern.

CONCLUSIONS

Urologists should consider approaching the topic of infertility when discussing the pros and cons of various prostate cancer therapies with their younger patients.

Outcomes Research: A Methodologic Review

OBJECTIVES

We explored the history and conceptual trends of outcomes research.

METHODS

We described different aspects of this field, after dividing it into conceptually distinct strata.

RESULTS

Outcomes research can be divided into macro, meso and micro levels. Each level is further subdivided. Macro-level research targets cost and health care utilization, as well as racial, ethnic and geopolitical population health determinants. Meso-level studies address effectiveness, variability, disease impact, clinical modeling and program evaluation studies. Finally, micro-level studies address all aspects of direct patient-clinician decision-making.

CONCLUSIONS

An explosion of outcomes research has occurred in the past decades. Wide access to information technology, data sharing and collaborative efforts between researchers represent some of the ingredients that did and will continue to fuel that growth.

Estimating the risk of long-term erectile, urinary and bowel symptoms resulting from prostate cancer treatment

Reports on long-term complications resulting from treatment for localized prostate cancer are very inconsistent. In order to estimate the risks of long-term erectile dysfunction, urine symptoms and bowel symptoms following prostatectomy (RP), external conventional or conformal beam radiation (ERT or CRT) and brachytherapy (BRT), 98 papers from the PubMed and Cochrane Clinical Trial databases were selected, reviewed and critically evaluated. The majority of papers were institution-based retrospective and prospective follow-up studies; only two of these studies measured the risk of developing more than one treatment complication. Due to differences in study designs and populations, it is difficult to directly compare studies and not meaningful to calculate summary estimates. In addition to focusing on randomized clinical trials and well-designed population based studies, future research should adopt standardized methodologies and should measure the risk of developing more than one treatment complication.

Clinical staging of prostate cancer: a computer-simulated study of transperineal prostate biopsy

OBJECTIVE

To identify the precise location of prostate cancer within the gland and thus possibly permit more aggressive therapy of the lesion, while potentially sparing the noncancerous gland from ablative therapy.

MATERIALS AND METHODS

Three-dimensional "solid" computer models were reconstructed for 86 autopsy specimens and 20 stage T1c radical prostatectomy specimens. Transperineal biopsies were simulated for grid sizes of 5-mm (method A) and 10-mm (method B) with an 18 G, 23-mm long biopsy needle. One or two biopsies per grid point were obtained for a total of 12-108 biopsies, depending on the size of the prostate. Clinically threatening cancers were defined as having volumes of > or = 0.5 mL or Gleason sum > or = 7.

RESULTS

Method A detected significantly more carcinomas than method B in both the autopsy and prostatectomy specimens (autopsy, 72 vs 51; prostatectomy, 50 vs 32, both P < 0.001). Method A also detected more clinically threatening cancers found at autopsy (38/40 vs 31/40, P = 0.008). Among autopsy patients with negative sextant biopsies whose disease was localized to one side, method A detected 72% and method B detected 29-43% (P < 0.001).

CONCLUSIONS

The results of this computer simulation show that 5- and 10-mm grid biopsies detect three-quarters and a third, respectively, at autopsy, of patients with the disease localized to one side of the prostate, which may be useful when planning highly selective ablative treatments in the future.

Patient Preferences in Prostate Cancer: A Clinician's Guide to Understanding Health Utilities

Prostate cancer treatments have positive and negative outcomes that must be taken into account when deciding how to proceed with a patient's care. One way to quickly determine a patient's preferences in this situation is to ascertain their health utilities for various health states. Health utilities are underutilized but powerful tools in aiding shared decision making between patients and physicians. This review is intended to inform physicians about the different techniques available, help the physician choose among them, and aid initial development of utilities for use in the clinic by way of the tables' references. A brief history, summary of applications and current directions of health utilities, and collection of references are provided to increase the reader's overall knowledge of health utilities and encourage their use in the clinic. Ultimately, the use and choice of one of these direct preference-based measures depends on the needs of the physician.

Racial treatment trends in localized/regional prostate carcinoma: 1992-1999

BACKGROUND

African-American men have a greater incidence of and mortality from prostate carcinoma compared with white men, and they are less likely to receive definitive therapy (radical prostatectomy or external beam radiation therapy). During the 1990s, the use of brachytherapy increased; however, its influence on racial and ethnic prostate carcinoma treatment trends remains unclear. The objective of this study was to describe treatment trends over the period 1992-1999 for localized/regional prostate carcinoma among white, Hispanic, and African-American men.

METHODS

Using the Surveillance, Epidemiology, and End Results (SEER) registry data from 1992 through 1999, logistic regression models were used to determine whether the odds of receiving a specific treatment modality differed by racial and ethnic group and whether the differences changed over time when the models were adjusted for age, marital status, tumor grade, and SEER site (geography).

RESULTS

The authors identified 142,340 men, including white men (81.6%), Hispanic men (6.4%), and African-American men (12.0%). Racial and ethnic differences in the rates of use of androgen-deprivation therapy/expectant management were noted; however, these differences appeared to lessen over time (P < 0.001). The rate of utilization of radical prostatectomy increased for Hispanic men, remained flat for African-American men, and decreased for white men. The utilization of brachytherapy and combination therapy increased for all three groups; however, the greatest increase in utilization was among white men.

CONCLUSIONS

Further research will be required to determine the patient-level and provider-level variables that influence racial and ethnic treatment differences in localized/regional prostate cancer.