A real world cost-minimization analysis comparing the use of different endoscopic staplers in video-assisted thoracic surgery lobectomy procedures.

Aim: China's cost-containment measures increasingly focus solely on the prices of consumable medical supplies without taking a broader perspective on differences in features and overall costs. This study compared two types of endoscopic staplers in video-assisted thoracoscopic surgery (VATS) lobectomy. Materials & methods: Electronic medical records for video-assisted thoracoscopic surgery from 2016 to 2017 were collected from a hospital in Anhui province. Two cohorts were retroactively defined based on stapler type. Total costs were compared using a cost-minimization analysis model. Probabilistic sensitivity analysis was performed. Results: In the base case, the group using more expensive staplers achieved overall cost savings of about $300 per procedure. Sensitivity analysis confirmed this result in 86.5% of cases. Conclusion: A price-only supply selection strategy may have unintended cost consequences.

Web-based decision aids for cancer clinical decisions: a systematic review and meta-analysis.

OBJECTIVE: The aim of this study is to evaluate the effectiveness of web-based decision aids (WDAs) on cancer-related clinical care in terms of different decision categories and by different cancer types. METHODS: Literature retrieval utilized highly inclusive algorithms searching randomized controlled trials (RCTs) in MEDLINE, EMBASE, and Cochrane Library and manual searching of eligible studies from reference lists of relevant articles. Two researchers examined the articles selected separately and extracted the information about the studies (e.g., decision category, sample sizes, and outcome indicators) using a data-extracting form and performed risk of bias assessment of the included studies with Begg's test, Egger's test, and Cochrane Collaboration's tool. Meta-analysis of the pooled effects of WDAs on outcome indicators was performed via Review Manager 5.2. RESULTS: A total of 24 RCTs met the inclusion criteria, involving 9846 participants. Overall meta-analysis revealed statistically significant effects on cancer decisional conflict, knowledge, and making informed choice with the overall effect sizes being -0.29 (standardized mean difference, SMD), 0.47 (SMD), and 1.92 (risk ratio, RR) respectively. Subgroup analysis revealed significant effects in indicators including decisional conflict, knowledge, satisfaction, participation in decision-making, and screening behavior, though some extent of heterogeneity and quality flaws existed among the included studies. CONCLUSIONS: Although our research results showed evidence of WDA effects on certain outcome indicators of cancer decisions, these results should be interpreted with caution given the heterogeneity and quality flaws. It is still premature to conclude whether WDA was effective in optimizing cancer clinical decision-making, and more efforts are needed in this area. PROSPERO REGISTRATION NUMBER: CRD42020218991.

Personalized hypertension management based on serial assessment and telemedicine (PHMA): a cluster randomize controlled trial protocol in Anhui, China.

BACKGROUND: Despite tremendous investment worldwide, hypertension treatment and control rates remain low. The complexity and long-term dynamics of influencing factors make personalized management inevitable and challenging. This protocol describes Personalized Hypertension Management in Anhui, China (PHMA), a project that uses a package of innovative approaches in tailoring interventions to individual patient's dynamic complications and contexts. METHODS/DESIGN: PHMA strives to reduce hypertension harms by eight "objective behaviors" (e.g., self-monitoring and reporting, healthy diet, physical exercise/activities). These objective behaviors are promoted through five intervention measures: support for self- monitoring, supervised machine communications, daily education or reminder messages, weekly blood pressure notification, and quarterly signed feedback. PHMA uses ten categories and over 300 variables in selecting and refining intervention procedures and content for individual patients. Efficacy of the intervention package is evaluated using a cluster randomized controlled trial design involving a total of 60 site communities and 3352 hypertension patients. Primary measure for the evaluation is systolic and diastolic blood pressure; while secondary evaluation measures include quality of life (EQ5D-5L), occurrence of hypertension-related complications (such as cerebral hemorrhage, coronary heart disease, myocardial or cerebral infarction), healthcare utilization and scores of objective behaviors. DISCUSSION: PHMA uses novel, low cost and sustainable approaches to tailor interventions to the dynamic conditions and contexts of individual patients. Unlike contemporary approaches to hypertension management which are mainly population based, each participant patient in PHMA applies a unique intervention package and all messages, feedbacks and other materials sent out to individual patients are different from each other. PHMA is the first project that adopts comprehensive tailoring and if proved effective, it should have important implications for future research, practice and policy-making. Trial registration ISRCTN10999269. July 17, 2020; https://doi.org/10.1186/ISRCTN10999269 .

Smartphone and web-based independent consultation and feedback for joint replacement surgeries: a randomized control trial protocol.

BACKGROUND: Cost control and usage regulation of medical materials (MMs) are the practical issues that the government pays close attention to. Although it is well established that there is great potential to mobilize doctors and patients in participating MMs-related clinical decisions, few interventions adopt effective measures against specific behavioral deficiencies. This study aims at developing and validating an independent consultation and feedback system (ICFS) for optimizing clinical decisions on the use of MMs for inpatients needing joint replacement surgeries. METHODS: Development of the research protocol is based on a problem or deficiency list derived on a trans-theoretical framework which incorporates including mainly soft systems-thinking, information asymmetry, crisis-coping, dual delegation and planned behavior. The intervention consists of two main components targeting at patients and doctors respectively. Each of the intervention ingredients is designed to tackle the doctor and patient-side problems with MMs using in joint replacement surgeries. The intervention arm receives 18 months' ICFS intervention program on the basis of the routine medical services; while the control arm, only the routine medical services. Implementation of the intervention is supported by an online platform established and maintained by the Quality Assurance Center for Medical Care in Anhui Province, a smartphone-based application program (APP) and a web-based clinical support system. DISCUSSION: The implementation of this study is expected to significantly reduce the deficiencies and moral hazards in decision-making of MMs using through the output of economic, efficient, sustainable and easy-to-promote cooperative intervention programs, thus greatly reducing medical costs and standardizing medical behaviors. TRIAL REGISTRATION NUMBER: ISRCTN10152297.

The Application of Collaborative Business Intelligence Technology in the Hospital SPD Logistics Management Model.

BACKGROUND: We aimed to apply collaborative business intelligence (BI) system to hospital supply, processing and distribution (SPD) logistics management model. METHODS: We searched Engineering Village database, China National Knowledge Infrastructure (CNKI) and Google for articles (Published from 2011 to 2016), books, Web pages, etc., to understand SPD and BI related theories and recent research status. For the application of collaborative BI technology in the hospital SPD logistics management model, we realized this by leveraging data mining techniques to discover knowledge from complex data and collaborative techniques to improve the theories of business process. RESULTS: For the application of BI system, we: (i) proposed a layered structure of collaborative BI system for intelligent management in hospital logistics; (ii) built data warehouse for the collaborative BI system; (iii) improved data mining techniques such as supporting vector machines (SVM) and swarm intelligence firefly algorithm to solve key problems in hospital logistics collaborative BI system; (iv) researched the collaborative techniques oriented to data and business process optimization to improve the business processes of hospital logistics management. CONCLUSION: Proper combination of SPD model and BI system will improve the management of logistics in the hospitals. The successful implementation of the study requires: (i) to innovate and improve the traditional SPD model and make appropriate implement plans and schedules for the application of BI system according to the actual situations of hospitals; (ii) the collaborative participation of internal departments in hospital including the department of information, logistics, nursing, medical and financial; (iii) timely response of external suppliers.

SPD-based Logistics Management Model of Medical Consumables in Hospitals.

BACKGROUND: With the rapid development of health services, the progress of medical science and technology, and the improvement of materials research, the consumption of medical consumables (MCs) in medical activities has increased in recent years. However, owing to the lack of effective management methods and the complexity of MCs, there are several management problems including MC waste, low management efficiency, high management difficulty, and frequent medical accidents. Therefore, there is urgent need for an effective logistics management model to handle these problems and challenges in hospitals. METHODS: We reviewed books and scientific literature (by searching the articles published from 2010 to 2015 in Engineering Village database) to understand supply chain related theories and methods and performed field investigations in hospitals across many cities to determine the actual state of MC logistics management of hospitals in China. RESULTS: We describe the definition, physical model, construction, and logistics operation processes of the supply, processing, and distribution (SPD) of MC logistics because of the traditional SPD model. With the establishment of a supply-procurement platform and a logistics lean management system, we applied the model to the MC logistics management of Anhui Provincial Hospital with good effects. CONCLUSION: The SPD model plays a critical role in optimizing the logistics procedures of MCs, improving the management efficiency of logistics, and reducing the costs of logistics of hospitals in China.

Life events and chronic physical conditions among left-behind farmers in rural China a cross-sectional study.

BACKGROUND: This study investigates the relationships between life events and chronic physical conditions among left behind farmers, a newly emerged weak group in vast rural China. METHODS: The study collected information about life events, chronic physical conditions, blood pressure and fasting blood glucose from 4681 famers living in 18 randomly selected villages (Lu'an, Anhui, China) from early November 2013 to the end of December 2013. It compared the risk and odds ratios (RRs/ORs) among different subgroups divided according two life event indices derived by adding up un-weighted-ratings and weighted-ratings based on multivariate logistic regression coefficients respectively. RESULTS: A total of 4040 (86.3 % eligible) farmers completed the survey. RRs between farmers with lower than the first 1/15-percentile of life event index and with higher life event index scores ranged 1.43-5.79 for chronic gastritis and 0.42-9.07 for prostatitis, 1.01-4.97 for cervicitis/vaginitis, 1.45-3.28 for cardio-cerebrovascular diseases, 1.12-1.58 for hypertension, 1.00-1.66 for diabetes, 1.07-3.35 for pre-diabetes and 5.00-55.00 for "other chronic physical conditions". CONCLUSIONS: Life events were independently linked with most of the chronic physical conditions in a dose-effectiveness way. RRs between subgroups divided by given percentile cutoff points of life event index compiled using logistic regression models turned out to be substantially higher than that between subgroups divided by same cutoff points of life event index produced via summing up the un-weighted Likert ratings of all the events studied.

Associations of blood pressure with common factors among left-behind farmers in rural China: a cross-sectional study using quantile regression analysis.

The whole range of blood pressure (BP) has important implications. Yet, published studies focus primarily on hypertension and hypotension, the two extremes of BP continuum. This study aims at exploring quantile-specific associations of BP with common factors. The study used cross-sectional survey, collected information about gender, age, education, body mass index (BMI), alcohol intake, diet risk behavior, life event index, physical activity, fasting capillary glucose (FCG), and systolic/diastolic blood pressure (SBP/DBP) and pulse pressure (PP) from farmers living in 18 villages from rural Anhui, China, and performed descriptive and multivariate and quantile regression (QR) analysis of associations of SBP, DBP, or PP with the 9 factors surveyed. A total of 4040 (86.3%) eligible farmers completed the survey. Average hypertension prevalence rate and SBP, DBP, and PP values estimated 43.20 ± 0.50% and 141.37 ± 21.98, 87.76 ± 12.23, and 53.63 ± 15.72 mm Hg, respectively. Multivariate regression analysis revealed that all the 9 factors were significantly (P < 0.05) associated with one or more of SBP, DBP, and PP. QR coefficients of SBP, DBP, or PP with different factors demonstrated divergent patterns and age, BMI, FCG, and life event index showed substantial trends along the quantile axis. Hypertension prevalence rate was high among the farmers. QR modeling provided more detailed view on associations of SBP, DBP, or PP with different factors and uncovered apparent quantile-related patterns for part of the factors. Both the population group studied and the trends in QR coefficients identified merit specific attention.

Relationships between stressful life events and impaired fasting glucose among left-behind farmers in rural China.

OBJECTIVE: This study aims at examining the effects of stressful life events on risk of impaired fasting glucose among left-behind farmers in rural China. METHODS: The study collected data about stressful life events, family history of diabetes, lifestyle, demographics and minimum anthropometrics from left-behind famers aged 40-70 years. Calculated life event index was applied to assess the combined effects of stressful life events experienced by the left-behind farmers and its association with impaired fasting glucose was estimated using binary logistic regression models. RESULTS: The prevalence of abnormal fasting glucose was 61.4% by American Diabetes Association (ADA) standard and 32.4% by World Health Organization (WHO) standard. Binary logistic regression analysis revealed a coefficient of 0.033 (P<.001) by ADA standard or 0.028 (P<.001) by WHO standard between impaired fasting glucose and life event index. The overall odds ratios of impaired glucose for the second, third and fourth (highest) versus the first (lowest) quartile of life event index were 1.419 [95% CI=(1.173, 1.717)], 1.711 [95% CI=(1.413, 2.071)] and 1.957 [95% CI=(1.606, 2.385)] respectively by ADA standard. When more and more confounding factors were controlled for, these odds ratios remained statistically significant though decreased to a small extent. CONCLUSIONS: The left-behind farmers showed over two-fold prevalence rate of pre-diabetes than that of the nation's average and their risk of impaired fasting glucose was positively associated with stressful life events in a dose-dependent way. Both the population studied and their life events merit special attention.

Association of risk of gastric cancer and consumption of tobacco, alcohol and tea in the Chinese population.

This study aimed at summarizing epidemiological research findings on associations between tobacco, alcohol and tea consumption and risk of gastric cancer (GC) in the Chinese population. The review searched PubMed, Embase, China National Knowledge Infrastructure (CNKI) and China Biology Medicine (CBM) databases and reference lists of review papers for all studies published in English or Chinese languages. Information extracted, via two independent researchers, from retrieved articles included first author, year of publication, study design, sample size, source of controls and adjusted odds ratio (OR) or relative risk (RR) with the corresponding 95% confidence intervals (CIs) for each category. Statistical analyses used software STATA version 12.0. The systematic search found 89 articles containing 25,821 GC cases and 135,298 non-cases. The overall random effects in terms of pooled OR and 95%CI for tobacco, alcohol and tea consumption were 1.62 (95%CI: 1.50-1.74), 1.57 (95%CI: 1.41-1.76) and 0.67 (95%CI: 0.59-0.76) respectively; while the heterogeneity among included studies ranged from 80.1% to 87.5%. The majority of subgroup analyses revealed consistent results with the overall analyses. All three behavioral factors showed statistically significant dose-dependent effects on GC (P<0.05). The study revealed that tobacco smoking and alcohol drinking were associated with over 1/2 added risk of GC, while tea drinking conferred about 1/3 lower risk of GC in the Chinese population. However, these results should be interpreted with caution given the fact that most of the included studies were based on a retrospective design and heterogeneity among studies was relatively high.

Patterns and trends with cancer incidence and mortality rates reported by the China National Cancer Registry.

National cancer registration reports provide a huge potential for identifying patterns and trends of important policy, research, prevention and treatment significance. As summary reports written on an annual basis, the China Cancer Registry Annual Reports (CCRARs) fall short from fully addressing their potential. This paper attempts to explore part of the patterns and trends hidden behind published CCRARs. It extracted data for cancer incidence rates (IRs) and mortality rates (MRs) for 2004, 2006 and 2009 from relevant CCRARs and portrayed 4 kinds of indicators in line graphs. The study showed that: a) all of the line graphs of age-specific IRs and MRs characterized typical "growth curves or histogram"; b) graphs of IRs and MRs for males and urban areas had higher peaks than that for females and rural regions; c) most of the line graphs of IR/MR ratios comprised a starting peak, a secondary peak and a decreasing tail and the secondary peaks for females and urban areas were higher than those for males and rural areas; d) most of the urban versus rural IR ratios valued above one, but most the urban versus rural MR ratios, below one; e) the accumulative IRs and MRs showed a stable increasing trend from 2004 to 2009 for urban areas, but mixed for rural regions.

Association between pancreatitis and subsequent risk of pancreatic cancer: a systematic review of epidemiological studies.

This study aimed to summarize published epidemiological evidence for the relationship between pancreatitis and subsequent risk of pancreatic cancer (PC). We searched Medline and Embase for epidemiological studies published by February 5th, 2014 examining the risk of PC in pancreatitis patients using highly inclusive algorithms. Information about first author, year of publication, country of study, recruitment period, type of pancreatitis, study design, sample size, source of controls and attained age of subjects were extracted by two researchers and Stata 11.0 was used to perform the statistical analyses and examine publication bias. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated with the random effects model. A total of 17 articles documenting 3 cohort and 14 case-control studies containing 14,667 PC cases and 17,587 pancreatitis cases were included in this study. The pooled OR between pancreatitis and PC risk was 7.05 (95%CI: 6.42-7.75). However, the pooled ORs of case-control and cohort studies were 4.62 (95%CI: 4.08-5.22) and 16.3 (95%CI: 14.3-18.6) respectively. The risk of PC was the highest in patients with chronic pancreatitis (pooled OR=10.35; 95%CI: 9.13-11.75), followed by unspecified type of pancreatitis (pooled OR=6.41; 95%CI: 4.93-8.34), both acute and chronic pancreatitis (pooled OR=6.13; 95%CI: 5.00-7.52), and acute pancreatitis (pooled OR=2.12; 95%CI: 1.59-2.83). The pooled OR of PC in pancreatitis cases diagnosed within 1 year was the highest (pooled OR=23.3; 95%CI: 14.0-38.9); and the risk in subjects diagnosed with pancreatitis for no less than 2, 5 and 10 years were 3.03 (95%CI: 2.41-3.81), 2.82 (95%CI: 2.12-3.76) and 2.25 (95%CI: 1.59-3.19) respectively. Pancreatitis, especially chronic pancreatitis, was associated with a significantly increased risk of PC; and the risk decreased with increasing duration since diagnosis of pancreatitis.

Association between gestational diabetes mellitus and subsequent risk of cancer: a systematic review of epidemiological studies.

PURPOSE: This study aimed at summarizing epidemiological evidence of the association between gestational diabetes mellitus (GDM) and subsequent risk of cancer. MATERIALS AND METHODS: We searched Medline, Embase, Cancer Lit and CINAHL for epidemiological studies published by February 1, 2014 examining the risk of cancer in patients with history of GDM using highly inclusive algorithms. Information about first author, year of publication, country of study, study design, cancer sites, sample sizes, attained age of subjects and methods used for determining GDM status were extracted by two researchers and Stata version 11.0 was used to perform the meta-analysis and estimate the pooled effects. RESULTS: A total of 9 articles documented 5 cohort and 4 case- control studies containing 10,630 cancer cases and 14,608 women with a history of GDM were included in this review. Taken together, the pooled odds ratio (OR) between GDM and breast cancer risk was 1.01 (0.87-1.17); yet the same pooled ORs of case-control and cohort studies were 0.87 (0.71-1.06) and 1.25 (1.00-1.56) respectively. There are indications that GDM is strongly associated with higher risk of pancreatic cancer (HR=8.68) and hematologic malignancies (HR=4.53), but no relationships were detected between GDM and other types of cancer. CONCLUSIONS: Although GDM increases the risk of certain types of cancer, these results should be interpreted with caution becuase of some methodological flaws. The issue merits added investigation and coordinated efforts between researchers, antenatal clinics and cancer treatment and registration agencies to help attain better understanding.

Psychosocial and Behavioral Interventions and Cancer Patient Survival Again: Hints of an Adjusted Meta-Analysis.

HYPOTHESES: Although there is evidence that psychosocial and behavioral interventions (PBIs) increase well-being, improve coping and adjustment, and reduce distress among cancer patients, findings regarding PBIs as a means for prolonging survival were not convincing. Conflicting findings resulted in tremendous controversies over the efficacy of PBIs. This study aims at estimating the pooled effects of PBIs on survival of cancer patients. STUDY DESIGN AND METHODS: Randomized controlled trials (RCTs) testing the effects of any kind of PBIs on the survival of cancer patients included in MEDLINE, EMBASE, Cancer Lit, CINAHL, Cochrane Library, and reference lists of relevant articles were retrieved and reviewed by 2 independent researchers. Data items derived from the articles included time and duration of study, intervention types and doses, and numbers of patients dying and surviving 1, 2, 4, and 6 years after intervention. Estimation of the collective effects of the interventions used meta-analysis via Review Manager (version 5). RESULTS: A total of 15 RCTs met inclusion criteria, involving 2041 subjects (1118 in intervention and 923 in control groups). Inclusive total mean Mantel-Haenszel risk ratios (RRs) ranged from 0.83 to 0.99, and 3 of these effect sizes were statistically nonsignificant. Yet when the RCTs with less than 30 hours of PBIs were excluded, all the RRs decreased to some extent, with the RR for the first 2 years being decreased to 0.69 (95% CI, 0.55-0.87) and 0.82 (95% CI, 0.71-0.95), respectively. CONCLUSION: PBIs with adequate intervention doses prolong survival at least for some cancer patients in the first 2 years after intervention, although longer term effects need to be determined via more studies.

Diagnostic value of rectal bleeding in predicting colorectal cancer: a systematic review.

This study aimed at summarizing published study findings on the diagnostic value of rectal bleeding (RB) and informing clinical practice, preventive interventions and future research areas. We searched Medline and Embase for studies published by September 13, 2013 examining the risk of colorectal cancer in patients with RB using highly inclusive algorithms. Data for sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and positive predictive value (PPV) of RB were extracted by two researchers and analyzed applying Meta-Disc (version 1.4) and Stata (version 11.0). Methodological quality of studies was assessed according to QUADAS. A total of 38 studies containing 5,626 colorectal cancer patients and 73,174 participants with RB were included. The pooled sensitivity and specificity were 0.47 (95% CI: 0.45-0.48) and 0.96 (95% CI: 0.96-0.96) respectively. The overall PPVs ranged from 0.01 to 0.21 with a pooled value of 0.06 (95% CI: 0.05-0.08). Being over the age of 60 years, change in bowel habit, weight loss, anaemia, colorectal cancer among first-degree relatives and feeling of incomplete evacuation of rectum appeared to increase the predictive value of RB. Although RB greatly increases the probability of diagnosing colorectal cancer, it alone may not be sufficient for proposing further sophisticated investigations. However, given the high specificity, subjects without RB may be ruled out of further investigations. Future studies should focus on strategies using RB as an "alarm" symptom and finding additional indications to justify whether there is a need for further investigations.

Effects of psycho-behavioral interventions on immune functioning in cancer patients: a systematic review.

PURPOSE: This study aimed at summarizing evidence about effects of psycho-behavioral interventions (PBIs) on immune responses among cancer patients and analyzing quality of published studies so as to inform future researches. METHODS: Literature retrieval utilized both highly inclusive algorithms searching randomized controlled studies published in English and Chinese and manual searching of eligible studies from references of relevant review papers. Two researchers examined the articles selected separately and extracted the information using a pre-designed form for soliciting data about the trials (e.g., sample size, disease status, intervention, immune responses) and quality ratings of the studies. Both narrative descriptions and meta-analysis (via Review manager 5) were used synthesizing the effects of PBIs on immune responses among cancer patients and state of art of the researches in this area. RESULTS: Seventy-six RCTs met inclusion criteria. PBIs implemented were divided into three major categories including psychological state adjustment, physical activity and dietary modification. Immune indicators measured included CD4+ cells, CD8+ cells, CD4/CDC8+ ratio, CD3+ cells, NK cell activity, etc. Effects of PBIs on immune responses documented in individual papers were mixed and pooled analysis of CD4+ cells, CD4+/CD8+ ratio, CD3+ cells, NKCA, IgG, IgM and IL-2 showed modest effects. However, there were huge discrepancies in intervention effects between studies published in English and Chinese and the results should be interpreted with caution. Besides, most studies suffer from some quality flaws concerning blinding, randomization procedures, compliance, attrition and intention-to-treat analyses, etc. CONCLUSIONS: Although there are considerable evidences of PBI effects on some immune indicators, the effect sizes are modest and it is still premature to conclude whether PBIs have effects on immune functions among cancer patients. There is a clear need for much more rigorous efforts in this area and future researches should pay particular attention to intervention dose and focus, sample size and comparable immune measures.

Refining and validating a two-stage and web-based cancer risk assessment tool for village doctors in China.

The big gap between efficacy of population level prevention and expectations due to heterogeneity and complexity of cancer etiologic factors calls for selective yet personalized interventions based on effective risk assessment. This paper documents our research protocol aimed at refining and validating a two-stage and web- based cancer risk assessment tool, from a tentative one in use by an ongoing project, capable of identifying individuals at elevated risk for one or more types of the 80% leading cancers in rural China with adequate sensitivity and specificity and featuring low cost, easy application and cultural and technical sensitivity for farmers and village doctors. The protocol adopted a modified population-based case control design using 72, 000 non-patients as controls, 2, 200 cancer patients as cases, and another 600 patients as cases for external validation. Factors taken into account comprised 8 domains including diet and nutrition, risk behaviors, family history, precancerous diseases, related medical procedures, exposure to environment hazards, mood and feelings, physical activities and anthropologic and biologic factors. Modeling stresses explored various methodologies like empirical analysis, logistic regression, neuro-network analysis, decision theory and both internal and external validation using concordance statistics, predictive values, etc..