Modelling Health State Utilities as a Transformation of Time to Death in Patients with Non-Small Cell Lung Cancer

BACKGROUND

When utilities are analyzed by time to death (TTD), this has historically been implemented by 'grouping' observations as discrete time periods to create health state utilities. We extended the approach to use continuous functions, avoiding assumptions around groupings. The resulting models were used to test the concept with data from different regions and different country tariffs.

METHODS

Five-year follow-up in advanced non-small cell lung cancer (NSCLC) was used to fit six continuous TTD models using generalized estimating equations, which were compared with progression-based utilities and previously published TTD groupings. Sensitivity analyses were performed using only patients with a confirmed death, the last year of life only, and artificially censoring data at 24 months. The statistically best-fitting model was then applied to data subsets by region and different EQ-5D-3L country tariffs.

RESULTS

Continuous (natural) [Formula: see text] and [Formula: see text] models outperformed other continuous models, grouped TTD, and progression-based models in statistical fit (mean absolute error and Quasi Information Criterion). This held through sensitivity and scenario analyses. The pattern of reduced utility as a patient approaches death was consistent across regions and EQ-5D tariffs using the preferred [Formula: see text] model.

CONCLUSIONS

The use of continuous models provides a statistically better fit than TTD groupings, without the need for strong assumptions about the health states experienced by patients. Where a TTD approach is merited for use in modelling, continuous functions should be considered, with the scope for further improvements in statistical fit by both widening the number of candidate models tested and the therapeutic areas investigated.

Reflections on estimands for patient-reported outcomes in cancer clinical trials

It is common and important to include the patient's perspective of the impact of treatment on health-related quality of life (HRQoL) outcomes. In this commentary, we focus on applying the new addendum to ICH E9 guideline E9 (R1) relating to the estimand framework to Patient Reported Outcomes (PROs) collected in cancer clinical trials, from a statistician's viewpoint. Currently, common practice for statistical analysis of PRO endpoints of published cancer clinical trials demonstrates ambiguity, leaving critical questions unspecified, hindering conclusions about the effect of treatment on PRO endpoints as well as comparability between clinical trials. To avoid this scenario, we advocate the systematic use of the estimand framework which requires the prospective definition of clear PRO research questions. Among the five attributes of the estimands framework, the definition of the endpoint (what is the right PRO measure and timeframe to target and why?), the intercurrent event identification and management (what happens with PRO data post-disease progression, what is the impact of death?) and the population-level summary (what is an acceptable statistical summary for PRO data?) require the most attention for PRO estimands. We identify good practice and highlight discussion points including the challenges of statistical analysis in the presence of missing and/or unobservable data and in relation to death. Through this discussion we highlight that there is no "statistical magic", but that the estimand framework will help you find out what you really want to know when quantifying the benefit of treatments from the patients' perspective.

Health-related quality of life of patients with resistant/intolerant chronic phase chronic myeloid leukemia treated with asciminib or bosutinib in the phase 3 ASCEMBL trial

In ASCEMBL, an open-label, randomized Phase 3 study, asciminib demonstrated superior efficacy and better safety profile compared with bosutinib in patients with chronic myeloid leukemia in chronic phase (CML-CP) previously treated with ≥2 tyrosine kinase inhibitors. Health-related quality of life (HRQOL) reported by patients is key to understanding the benefit and impact of treatment on patients' lives, and is becoming increasingly important as the life expectancy of CML-CP patients increases and patients require long-term treatment. In ASCEMBL, patients completed questionnaires to assess CML symptoms and interference with daily life (M.D. Anderson Symptom Inventory - CML [MDASI-CML]), general HRQOL (five-level EQ-5D [EQ-5D-5L], Patient Global Impression of Change - CML [PGIC-CML]), and impact of CML on working life and activity (Work Productivity and Activity Impairment questionnaire - CML [WPAI-CML]). Patients' CML symptoms and HRQOL remained stable during 48 weeks of treatment with asciminib, with a general trend for decreased CML symptom severity, particularly for fatigue, and improvement in HRQOL. A clinically meaningful increase in diarrhea severity was observed in patients treated with bosutinib compared to asciminib. These data provide better understanding of the patient perspective and treatment impact on HRQOL in a later-line setting, where little information has been published to date.

First-line nivolumab plus ipilimumab with two cycles of chemotherapy versus chemotherapy alone (four cycles) in metastatic non-small cell lung cancer: CheckMate 9LA 2-year patient-reported outcomes

BACKGROUND

In CheckMate 9LA (NCT03215706), first-line nivolumab plus ipilimumab with chemotherapy (2 cycles) significantly improved overall survival versus chemotherapy (4 cycles) in patients with metastatic non-small cell lung cancer and no known sensitising epidermal growth factor receptor/anaplastic lymphoma kinase alterations. We present exploratory patient-reported outcomes (PROs; minimum follow-up, 2 years).

METHODS

In patients (N = 719) randomised 1:1 to nivolumab plus ipilimumab with chemotherapy or chemotherapy alone, disease-related symptom burden and health-related quality of life were assessed using the Lung Cancer Symptom Scale (LCSS) and 3-level EQ-5D (EQ-5D-3L). Treatment-phase changes in LCSS average symptom burden index (ASBI), LCSS three-item global index (3-IGI) and EQ-5D-3L visual analogue scale (VAS) and utility index (UI) over time were analysed descriptively and using mixed-effect model repeated measures. Time-to-deterioration/improvement analyses were conducted.

RESULTS

Treatment-phase PRO questionnaire completion rates were >80%. Mean treatment-phase changes showed no deterioration from baseline in both arms for LCSS ASBI/3-IGI and EQ-5D-3L VAS/UI; however, minimally important differences were not met. Mixed-effect model repeated measures analyses showed overall reduction in symptom burden from baseline for both arms; changes from baseline for LCSS 3-IGI and EQ-5D-3L VAS/UI were numerically improved with nivolumab plus ipilimumab with chemotherapy versus chemotherapy, but minimally important differences were not met. Nivolumab plus ipilimumab with chemotherapy delayed time-to-definitive-deterioration versus chemotherapy (LCSS ASBI: hazard ratio, 0.62 [95% confidence interval, 0.45-0.87]); results were similar across PRO measures.

CONCLUSIONS

At 2-year minimum follow-up, first-line nivolumab plus ipilimumab with chemotherapy reduced the risk of definitive deterioration in disease-related symptom burden and health-related quality of life versus chemotherapy and maintained QoL in patients with metastatic non-small cell lung cancer.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier, NCT03215706.

Three-year follow-up and patient-reported outcomes from CheckMate 078: Nivolumab versus docetaxel in a predominantly Chinese patient population with previously treated advanced non-small cell lung cancer

OBJECTIVES

In the phase 3 CheckMate 078 study, nivolumab prolonged overall survival (OS) and showed a favorable safety profile versus docetaxel in a predominantly Chinese patient population with previously treated advanced non-small cell lung cancer (aNSCLC). However, long-term efficacy, safety, and health-related quality of life findings with second-line nivolumab are very limited in Asian patients with previously treated aNSCLC. Here, we report updated clinical data and patient-reported outcomes (PROs) from the phase 3 CheckMate 078 trial with a 3-year minimum follow-up.

MATERIALS AND METHODS

Patients with aNSCLC and disease progression after platinum-doublet chemotherapy were randomized 2:1 to nivolumab (3 mg/kg every 2 weeks) or docetaxel (75 mg/m2 every 3 weeks) until progression or unacceptable toxicity. The primary endpoint was OS; secondary endpoints included objective response rate, progression-free survival, safety, and disease-related symptom deterioration assessed using the Lung Cancer Symptom Scale (LCSS) by Week 12. Additional PRO assessments were exploratory endpoints.

RESULTS

At ≥ 37.3 months follow-up, 3-year OS rates were 19% with nivolumab and 12% with docetaxel; 30% and 0% of responders remained in response for ≥ 3 years, respectively. Incidence of treatment-related adverse events occurring after 2 years was lower than during the first 2 years. No new treatment-related deaths were reported. By Week 12 of treatment, rates of disease-related symptom deterioration were 32% with nivolumab and 47% with docetaxel. Completion rates for PRO questionnaires were ≥ 80% in both arms. Clinically meaningful and sustained improvements in LCSS Average Symptom Burden Index scores and delayed time to first symptom deterioration were observed with nivolumab against docetaxel.

CONCLUSIONS

At 3 years, nivolumab continued to demonstrate survival benefit versus docetaxel, exhibiting improvements in disease-related symptoms and overall health status in a predominantly Chinese patient population with previously treated aNSCLC. No new safety signals were observed. These findings are similar to the global population.

Health-related quality of life (HRQoL) in patients (pts) with advanced esophageal squamous cell carcinoma (ESCC) treated with nivolumab (N) plus chemotherapy (CT) or nivo plus ipilimumab (I) versus chemo: Results from CheckMate 648

262

Background: This analysis evaluated HRQoL as exploratory endpoints in CheckMate 648, a randomized, open-label, global Phase 3 study, evaluating treatment with N+I, N+CT and CT alone in inoperable advanced, recurrent, or metastatic ESCC. Methods: The effects of N+I vs N+CT vs CT on HRQoL were assessed using the Functional Assessment of Cancer Therapy-Esophageal (FACT-E) (including the GP5 item to assess impact of side effects) and EQ-5D-3L. A mixed model for repeated measures was used to evaluate longitudinal changes from baseline (BL) and differences between treatment groups. Comparison of the risk of being bothered by the side effects of treatment was estimated for the GP5 using generalized estimating equation (GEE). Time to confirmed deterioration (TTCD) was assessed using Kaplan-Meier plots along with Cox proportional hazard models. Analyses were conducted on both the all-randomized population and the subset of patients with PD-L1 expression ≥1%. Results: 970 pts were randomized 1:1:1 to N+I (n=325), N+CT (n=321), or CT (n=324). 90% of pts completed both a BL and at least one on-treatment assessment and were included in the PRO analysis population. FACT-E (all randomized pts). Study showed similar BL scores across all 3 treatment groups. Changes from BL showed a trend towards better HRQoL for pts treated with N+I and N+CT compared to CT alone, however these results were not statistically significant. Patients treated with N+I had significantly decreased risk of experiencing bother associated with the side effects of treatment than patients treated with either N+CT or CT. TTCD analysis demonstrated delayed deterioration for pts treated with N+CT vs CT. Findings for PD-L1 ≥1% subpopulation were similar to all randomized pts. Conclusions: In pts with inoperable advanced, recurrent, or metastatic ESCC, HRQoL is maintained throughout treatment with N+I and N+CT. Trends towards better HRQoL and decreased risk of deterioration were observed with N+I and N+CT compared to CT alone. Clinical trial information: NCT03143153. [Table: see text]

Checkmate 577:Health-related quality of life (HRQoL) in a randomized, double-blind phase III study of nivolumab (NIVO) versus placebo (PBO) as adjuvant treatment in patients (pts) with resected esophageal or gastroesophageal junction cancer (EC/GEJC)

167

Background: NIVO is the first adjuvant therapy to provide a statistically significant and clinically meaningful improvement in disease-free survival (DFS) versus PBO in resected EC/GEJC following neoadjuvant chemoradiotherapy as demonstrated by CheckMate 577. NIVO was well tolerated with an acceptable safety profile. This analysis provides additional information on the exploratory HRQoL endpoints in this clinical trial. Methods: The effect of NIVO versus PBO on HRQoL, including general and disease-related symptoms, functioning, disease burden, and overall QoL, was assessed using FACT-E and EQ-5D-3L patient-reported outcome (PRO) questionnaires administered at baseline (BL), every 4 weeks during the 12-month treatment period, and at post-treatment follow-up visits (up to 2 years after last dose). Longitudinal change from BL in PRO scores over 12 months was assessed using descriptive statistics. Additionally, mixed model for repeated measures and time to deterioration analyses evaluated the difference between treatment with NIVO and PBO (data not shown). Results: 794 pts with EC/GEJC were randomized 2:1 to NIVO (n = 532) or PBO (n = 262). PRO completion rates were ≥ 95% at BL and ~ 90% at 12 months on treatment. Mean (SD) BL HRQoL scores were similar between treatment arms for the FACT-E total score (NIVO: 133.40 [20.97]; PBO: 134.03 [20.40]); esophageal cancer subscale (ECS; NIVO: 50.2 [9.3]; PBO: 50.1 [8.9]); EQ-5D Visual Analogue Scale (NIVO: 70.4 [22.3]; PBO: 69.1 [24.1]); and EQ-5D Utility Index (NIVO: 0.820 [0.179]; PBO: 0.831 [0.163]) based on the UK value set. Descriptive analyses showed a trend for increases from baseline at most time points through week 49 for both NIVO and PBO treatment groups for FACT-E total score, ECS, and EQ-5D Visual Analogue Scale and Utility Index. Conclusions: Preliminary results from CheckMate 577 demonstrated that pts on NIVO treatment showed trends of improvement in both esophageal-specific and general HRQoL. Similar trends were also observed in pts treated with PBO over 1 year. Pts treated with NIVO did not experience a reduction in HRQoL, further supporting clinical data to demonstrate treatment benefit and tolerability for adjuvant NIVO in pts with resected EC/GEJC. Clinical trial information: NCT02743494.

Improving patient-clinician communication following nephrectomy in renal cell carcinoma: Development, content validation and pilot testing of a conversation aid tool

OBJECTIVES

This study developed, and established the content validity, of a conversation aid tool (CAT) for use in clinical practice with renal cell carcinoma (RCC) patients who receive a curative nephrectomy and are at high-risk of recurrence. The CAT was pilot tested in a sample of RCC patients to establish whether the CAT increases knowledge of RCC, treatment options (such as adjuvant therapy), and care options.

METHODS

A cross-sectional, mixed methods design was used involving initial, exploratory interviews with RCC patients, RCC specialists and a steering group. Further content validation interviews were conducted with RCC patients and specialists. A web-based survey was conducted with RCC patients (N = 60), to compare the CAT versus a standard of care (SOC) consultation comparator tool on patient knowledge.

RESULTS

Findings from exploratory interviews were used to develop the CAT. Content validation interviews demonstrated that the CAT was well understood and relevant to RCC patients. The web-based survey demonstrated that viewing the CAT significantly improved participants knowledge of RCC, and care options, when compared to the SOC.

CONCLUSION

The findings highlight that the CAT is a relevant, comprehensive and well-understood tool for use in the post-nephrectomy consultation.

PRACTICE IMPLICATIONS

Use of the CAT may increase patient knowledge of RCC and care options.

What is an estimand & how does it relate to quantifying the effect of treatment on patient-reported quality of life outcomes in clinical trials?

BACKGROUND

Published in 2019, a new addendum to the ICH E9 guideline presents the estimand framework as a systematic approach to ensure alignment among clinical trial objectives, trial execution/conduct, statistical analyses, and interpretation of results. The use of the estimand framework for describing clinical trial objectives has yet to be extensively considered in the context of patient-reported outcomes (PROs). We discuss the application of the estimand framework to PRO objectives when designing clinical trials in the future, with a focus on PRO outcomes in oncology trial settings as our example. MAIN: We describe the components of an estimand and take a naïve PRO trial objective to illustrate how to apply attributes described in the estimand framework to inform construction of a detailed clinical trial objective and its related estimand. We discuss identifying potential post-randomization events that alter the interpretation of the endpoint or render its observation impossible (also defined as intercurrent events) in the context of PRO endpoints, and the implications of how to handle intercurrent events in the construction of the PRO objective. Using a simple objective statement, "What is the effect of treatment X on patient's quality of life?", we build up an example estimand statement and also use a previously published phase III oncology clinical trial to illustrate how an estimand for a PRO objective could have been written to align to the estimate framework.

CONCLUSION

The use of the estimand framework, as described in the new ICH E9 (R1) addendum guideline will become a key common framework for developing clinical trial objectives for evaluating effects of treatment. In the context of considering PROs, the framework provides an opportunity to more precisely specify and build the rationale for patient-focused objectives. This will help to ensure that clinical trials used for registration are designed and analysed appropriately, enabling all stakeholders to accurately interpret conclusions about the treatment effects for patient-focused outcomes.

Patient-reported quality of life (QoL) of advanced melanoma patients in a Phase 3 study of nivolumab (NIVO) with or without ipilimumab (IPI) versus IPI: CheckMate 067 4-year data

9551

Background: Early CheckMate 067 data showed maintenance of QoL in patients with advanced melanoma treated with NIVO with or without IPI based on 1-year data; however, the long-term QoL of these patients has not been evaluated previously. The patient-reported outcomes (PRO) analyses presented here for CheckMate 067 is the first time QoL results have been evaluated in this melanoma population over a 4-year period. Methods: In CheckMate 067, 945 patients were randomized 1:1:1 to receive NIVO (3mg/kg Q2W) + placebo (PBO), NIVO+IPI (1mg/kg+3mg/kg Q3W X 4) followed by NIVO (3mg/kg Q2W), or IPI (3mg/kg Q3W X 4) + PBO. PRO data were collected using the EORTC QLQ-C30 (5 functional domains, 9 symptoms, global health status) and EQ-5D-3L (utility index, VAS) at baseline, weeks 1 and 5 of each 6-week tx cycle, and off-tx follow-up (FU) visits. Mean changes in PRO scores from baseline (randomization) were evaluated descriptively for the PRO analysis population, with conclusions drawn from time points with ≥30 patients completing assessments per tx arm. Least square mean changes from baseline were assessed using a longitudinal mixed model analysis adjusting for repeated measures, including all on-tx data for patients. Results: Completion rates at baseline ranged from 89-92% across tx arms. Of 813 patients included in the PRO analysis population (278 NIVO, 274 NIVO+IPI, 261 IPI), > 200 receiving tx remained for the first year, > 100 receiving tx remained after 2 years, and > 50 receiving tx remained after 3 years. QoL, including assessment of functioning and symptom burden, was maintained for the duration of tx and in FU, with no sustained clinically meaningful deterioration in any tx arm. Global health status (EORTC QLQ-C30) and general QoL (EQ-5D-3L VAS) were also maintained during prolonged tx. Overall, results from the mixed model analysis support the long-term maintenance of QoL over the course of tx. Conclusions: Patient-reported QoL and symptoms in patients with advanced melanoma were maintained from baseline during extended tx with NIVO with or without IPI. Clinical trial information: NCT01844505.

Quality of life (QoL) and symptom burden in patients (pts) with advanced melanoma during the treatment-free interval (TFI) after discontinuation of nivolumab (NIVO) or NIVO plus ipilimumab (IPI)

9568

Background: The TFI after discontinuation of study therapy has been reported to be longer with NIVO+IPI compared to NIVO or IPI alone, but QoL during the TFI has not been reported in advanced melanoma (MEL) studies. 1-y data from CheckMate (CM) 067 showed maintenance of QoL after treatment (tx) discontinuation with NIVO or NIVO+IPI. Here, we present long-term QoL results from CM 067 during the TFI (period off study tx and free of subsequent therapy), based on an updated 4-y dataset. Methods: In CM 067, 945 pts were randomized 1:1:1 to receive NIVO 3 mg/kg + placebo; NIVO 1 mg/kg + IPI 3 mg/kg × 4, then NIVO 3 mg/kg; or IPI 3 mg/kg × 4 + placebo. Patient-reported outcomes (PRO) were collected using the EORTC QLQ-C30 (5 functional domains, 9 symptoms, global health status) and EQ-5D-3L (utility index, visual analog scale) at baseline, on-tx visits, and follow-up (FU) visits 1 (FU1; 30 d after last dose) and 2 (FU2; 84 d after FU1). EQ-5D-3L was also collected at survival FU visits every 3 mo after FU2 in the first year and every 6 mo thereafter. Within the PRO analysis population, 480 of 764 pts who discontinued protocol tx (for any reason, including drug toxicity; n = 155) had PRO scores, collected prior to initiation of subsequent anticancer therapy, evaluated. Mean changes in PRO scores from last on-tx visit were reported for each FU visit. Results: Across tx arms, PRO scores were maintained from last on-tx visit to FU1 or FU2 for pts who discontinued for any reason. EORTC QLQ-C30 functional and symptom scales remained stable during the TFI. Among pts who discontinued tx due to toxicity, clinically meaningful deterioration in QoL was observed in a few subscales at FU1, but QoL was restored to the same level as the last on-tx visit in all except one subscale by FU2. PRO scores remained stable beyond FU2 for the EQ-5D-3L, regardless of reason for discontinuation. Data interpretation at later FU visits was limited due to smaller sample sizes. Sensitivity analyses for mean change in PRO scores from randomization to FU visits will be presented. Conclusions: QoL was maintained during the TFI, compared to last on-tx visit, in pts with MEL treated with NIVO or NIVO+IPI.

Association Between Plasma Genotyping and Outcomes of Treatment With Osimertinib (AZD9291) in Advanced Non-Small-Cell Lung Cancer

PURPOSE

Third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have demonstrated potent activity against TKI resistance mediated by EGFR T790M. We studied whether noninvasive genotyping of cell-free plasma DNA (cfDNA) is a useful biomarker for prediction of outcome from a third-generation EGFR-TKI, osimertinib.

METHODS

Plasma was collected from all patients in the first-in-man study of osimertinib. Patients who were included had acquired EGFR-TKI resistance and evidence of a common EGFR-sensitizing mutation. Genotyping of cell-free plasma DNA was performed by using BEAMing. Plasma genotyping accuracy was assessed by using tumor genotyping from a central laboratory as reference. Objective response rate (ORR) and progression-free survival (PFS) were analyzed in all T790M-positive or T790M-negative patients.

RESULTS

Sensitivity of plasma genotyping for detection of T790M was 70%. Of 58 patients with T790M-negative tumors, T790M was detected in plasma of 18 (31%). ORR and median PFS were similar in patients with T790M-positive plasma (ORR, 63%; PFS, 9.7 months) or T790M-positive tumor (ORR, 62%; PFS, 9.7 months) results. Although patients with T790M-negative plasma had overall favorable outcomes (ORR, 46%; median PFS, 8.2 months), tumor genotyping distinguished a subset of patients positive for T790M who had better outcomes (ORR, 69%; PFS, 16.5 months) as well as a subset of patients negative for T790M with poor outcomes (ORR, 25%; PFS, 2.8 months).

CONCLUSION

In this retrospective analysis, patients positive for T790M in plasma have outcomes with osimertinib that are equivalent to patients positive by a tissue-based assay. This study suggests that, upon availability of validated plasma T790M assays, some patients could avoid a tumor biopsy for T790M genotyping. As a result of the 30% false-negative rate of plasma genotyping, those with T790M-negative plasma results still need a tumor biopsy to determine presence or absence of T790M.

Ticagrelor yields consistent dose-dependent inhibition of ADP-induced platelet aggregation in patients with atherosclerotic disease regardless of genotypic variations in P2RY12, P2RY1, and ITGB3

The platelet P2Y(12) receptor is the target of clopidogrel therapy, which has been shown to reduce thromboembolic complications of atherosclerotic disease but has limitations in terms of variability of response and irreversibility of effect. This receptor is also a target for ticagrelor (AZD6140), the first reversibly binding oral P2Y(12) receptor antagonist that does not require metabolic activation and yields more consistent inhibition of platelet aggregation than clopidogrel therapy. Single nucleotide polymorphisms (SNPs) have been described in the gene for this receptor (P2RY12), some of which have been associated with variability in platelet reactivity. SNPs in P2RY1 and ITGB3 have also been reported by some groups to affect platelet reactivity to adenosine diphosphate (ADP). We assessed whether SNPs in these genes influenced the pharmacodynamic response to ticagrelor in patients enrolled in both the DISPERSE study (stable atherosclerotic disease) and the DISPERSE2 study (non-ST-segment elevation acute coronary syndromes). Platelet aggregation data (at baseline and 4 weeks) and DNA samples from clopidogrel-naive Caucasian patients treated with ticagrelor were available for 151 patients. Seventy four SNPs within three genes were genotyped. After adjustment for multiple comparisons, none of these SNPs were found to significantly influence inhibition of ADP-induced platelet aggregation by ticagrelor.

Classification of rheumatoid arthritis status with candidate gene and genome-wide single-nucleotide polymorphisms using random forests

Using the North American Rheumatoid Arthritis Consortium (NARAC) candidate gene and genome-wide single-nucleotide polymorphism (SNP) data sets, we applied regression methods and tree-based random forests to identify genetic associations with rheumatoid arthritis (RA) and to predict RA disease status. Several genes were consistently identified as weakly associated with RA without a significant interaction or combinatorial effect with other candidate genes. Using random forests, the tested candidate gene SNPs were not sufficient to predict RA patients and normal subjects with high accuracy. However, using the top 500 SNPs, ranked by the importance score, from the genome-wide linkage panel of 5742 SNPs, we were able to accurately predict RA patients and normal subjects with sensitivity of approximately 90% and specificity of approximately 80%, which was confirmed by five-fold cross-validation. However, in a complete training-testing framework, replication of genetic predictors was less satisfactory; thus, further evaluation of existing methodology and development of new methods are warranted.

Quality assurance and continuing education needs of rural and remote general practitioners: how are they changing?

The Royal Australian College of General Practitioners' (RACGP) 1998 Rural Quality Assurance and Continuing Education (QA & CE) Needs Assessment Project was designed to generate sufficient data to inform strategic planning for rural and remote GPs participating in the College's QA & CE Program. Results indicated that the demand for QA & CE activities has changed over the past 12 years. Three distinct streams of continuing education emerged, where once only one was researched. This reflected a move towards continuing professional development (CPD) rather than purely continuing medical education (CME). However, differences between the CME needs identified suggested that national data could not be reduced to the local level. Data on CME in which rural and remote GPs felt underserviced, proved more useful in relation to other workforce variables such as age, length of service and gender. A broad 'rural set' of CPD topics was established, and the survey yielded information on learning format preferences that will be of use to providers of QA & CE activities for rural GPs across Australia.

The learning preferences of rural and remote general practitioners. A quantitative analysis and its implications for the RACGP QA&CE program

AIM

To establish the QA&CE needs of rural and remote GPs. In order to assess the fit between The Royal Australian College of General Practitioners' QA&CE program and these needs, learning preferences identified in this survey are compared to previous research published in Australia, 1987-1997, and matched against program objectives and guidelines.

METHOD

In 1998 the RACGP surveyed 900 rural general practitioners (GPs) across Australia in three randomised samples. These samples were stratified respectively by membership of the Rural Faculty of the RACGP and practice location in RRMAs 3-7. The overall response rate was 78%.

RESULTS

Self directed learning was rated by 65.3% of respondents as a preferred method of maintaining professional standards, a rating that corresponded significantly to familiarity with this approach to learning (p = 0.006), and even more so among younger GPs. This was second only to CME at 85.6%. By comparison, there was a low orientation toward some learning methods identified elsewhere as effective, such as clinical audit (15.6%) and peer review (14.5%). There were positive correlations, however, between preference and familiarity for these methods (p < 0.001).

CONCLUSIONS

The results indicate that self directed learning, a major learning preference of rural and remote GPs, may currently be underserviced by the RACGP's QA&CE program. The program also needs to promote more strongly the effectiveness of less preferred modes of education, such as peer review and clinical audit, given the stronger preference indicated for less effective modes.

Hyperglycemia-induced attenuation of rectal perception depends upon pattern of rectal balloon inflation

This study investigated the effects of acute hyperglycemia on conscious rectal perception in response to two different rectal distension paradigms. Eleven healthy males were studied in random order on two separate days during euglycemia and hyperglycemia with blood glucose concentrations clamped to 3.8 +/- 0.6 and 14.8 +/- 0.86 mmol/liter, respectively. In order to evoke sensory responses, rapid phasic and ramplike distensions were applied to an intrarectal balloon. Rectal sensation thresholds for initial sensation, sensation of stool and discomfort, and sensory intensities were recorded. Additionally, anorectal motor responses were investigated during phasic distension. Acute hyperglycemia did not modify rectal sensory pressure thresholds and perception scores in response to phasic distension. Neither did hyperglycemia alter the resting anal sphincter pressure, the pressure threshold for eliciting the rectoanal inhibitory reflex, or the maximal anal squeeze pressure. In contrast, hyperglycemia attenuated rectal perception in response to ramplike distension. The pressure thresholds, 10.0 +/- 1.8 and 17.0 +/- 3.6 mm Hg for initial sensation and discomfort, respectively, during hyperglycemia were significantly higher than the corresponding thresholds of 4.4 +/- 1.4 and 11.4 +/- 1.9 mm Hg observed during euglycemia (P < 0.01). Higher rectal pressures were observed at all intensities of sensation of stool and discomfort during hyperglycemia than those obtained during euglycemia (P < 0.01). Hyperglycemia did not alter the compliance of the rectum. The results of this study demonstrate that acute hyperglycemia attenuates rectal perception, and this attenuation depends upon the type of distension employed. Our findings also demonstrate that anal sphincter motor function is not appreciably modified by hyperglycemia.

High pressure liquid chromatographic determination of cyclosporin A in plasma

A sensitive and rapid high performance liquid chromatographic method was developed for the determination of Cyclosporin A in plasma. Cyclosporin A was isolated from methanol-precipitated plasma using miniature compressed silica reverse-phase columns (Sep-Paks). In the method, 1 ml serum is precipitated in 3 ml methanol. After centrifugation 2 ml of supernatant is diluted in 1 ml water and the sample flushed through a washed Sep-Pak. The sample on the miniature column is washed with water and 75% v/v methanol, and Cyclosporin A is eluted in 1 ml methanol. At least 80% of the drug is recovered. Samples are analyzed on a reverse-phase column, the mobile phase is methanol:water (95:5) and detection is conducted at 205 nm. The detection limits were less than 100 ng/ml, but in plasma some interference was observed, especially at concentrations below 1000 ng/ml.

The Photovoltaic Effect in Natural Lead Sulphide

Australian samples of natural lead sulphide have been used as radiation detectors In the near infra-red. The nature of the photovoltaic effect has been investigated and the sensitivity of some cells measured. The electrical properties of bulk samples have been measured. The results have been compared with similar measurements given by other authors for thin lead sulphide films, and a close correlation has been established between them.