Improving decision making about clinical trial participation - a randomised controlled trial of a decision aid for women considering participation in the IBIS-II breast cancer prevention trial.

BACKGROUND: Decision aids may improve informed consent in clinical trial recruitment, but have not been evaluated in this context. This study investigated whether decision aids (DAs) can reduce decisional difficulties among women considering participation in the International Breast Cancer Intervention Study-II (IBIS-II) trial. METHODS: The IBIS-II trial investigated breast cancer prevention with anastrazole in two cohorts: women with increased risk (Prevention), and women treated for ductal carcinoma in situ (DCIS). Australia, New Zealand and United Kingdom participants were randomised to receive a DA (DA group) or standard trial consent materials (control group). Questionnaires were completed after deciding about participation in IBIS-II (post decision) and 3 months later (follow-up). RESULTS: Data from 112 Prevention and 34 DCIS participants were analysed post decision (73 DA; 73 control); 95 Prevention and 24 DCIS participants were analysed at follow-up (58 DA; 61 control). There was no effect on the primary outcome of decisional conflict. The DCIS-DA group had higher knowledge post decision, and the Prevention-DA group had lower decisional regret at follow-up. CONCLUSIONS: This was the first study to evaluate a DA in the clinical trial setting. The results suggest DAs can potentially increase knowledge and reduce decisional regret about clinical trial participation.

Improving informed consent: pilot of a decision aid for women invited to participate in a breast cancer prevention trial (IBIS-II DCIS).

BACKGROUND: Patients and clinicians report difficulties with the process of informed consent to clinical trials and audiotape audits show that critical information is often omitted or poorly presented. Decision aids (DAs) may assist in improving consent. AIMS: This study piloted a DA booklet for a high priority breast cancer prevention trial, IBIS-II DCIS, which compares the efficacy of an aromatase inhibitor (anastrozole) with tamoxifen in women who have had surgery for ductal carcinoma in situ (DCIS). METHOD: Thirty-one Australian women participating in the IBIS-I breast cancer prevention trial and who are currently in follow-up agreed to read the IBIS-II DCIS participant information sheet and the DCIS DA booklet, complete a set of standardized questionnaires, and provide feedback on the DA via a semi-structured phone interview. RESULTS: Women found the DA helpful in deciding about trial participation, reporting that it aided their understanding over and above the approved IBIS-II DCIS participant information sheet and was not anxiety provoking. Women's understanding of the rationale and methods of clinical trials and the IBIS-II DCIS trial was very good; with more than 80% of items answered correctly. The only areas that were not understood well were the concepts of randomization and blinding. CONCLUSIONS: This study suggests that the DA will be acceptable to and valued by potential participants in the IBIS-II DCIS study. The revised DA is currently being evaluated prospectively in a randomized controlled trial. If successful, such DAs could transform the consent process to large clinical trials and may also reduce dropout rates.

The occurrence of cancer in a cohort of New South Wales coal miners.

To describe the incidence of cancer in coal miners in New South Wales (NSW) between 1973 and 1992, an inception cohort of all male coal industry employees who entered the industry between 1 January 1973 and 31 December 1992 was constructed from the medical examination records of the Joint Coal Board. This cohort was matched with the NSW State Cancer Registry to determine the occurrence and type of cancer. In the cohort of 23,630 men, 297 developed 301 primary cancers in the 20-year period of observation. The standardised incidence ratio (SIR) for all cancers was 0.82. Stomach cancer has been reported to be common in coal miners but the SIR for stomach cancer was not higher than average in this cohort. A cluster of non-Hodgkin's lymphoma has been reported in a NSW coal mine but an increased risk of this cancer was not evident in the industry as a whole. Similarly a cluster of cases of brain tumour has been reported. In this cohort, the SIR for brain tumour was 1.05 (95 per cent confidence interval (CI) 0.57 to 1.76) and a risk for brain tumour remains unconfirmed. The SIR for malignant melanoma was 1.13 (CI 0.90 to 1.39) together and 2.02 (CI 1.31 to 2.98) for those workers who started in an open-cut mine. Overall, there does not appear to be a general risk of cancer in the NSW coal industry. Open-cut miners have an increased risk of malignant melanoma, which may be related to their exposure to the sun at work.

Mortality in the New South Wales coal industry, 1973-1992.

OBJECTIVE: To study the mortality of coalminers in New South Wales (NSW) between 1973 and 1992. DESIGN AND PARTICIPANTS: An inception cohort of all male coal industry employees who entered the industry between 1 January 1973 and 31 December 1992 was constructed from the records of Joint Coal Board medical examinations. This cohort was matched with the NSW Death Register to determine the number and causes of deaths in cohort members. RESULTS: The cohort consisted of 23,630 men; 491 died during the study period. The standardised mortality ratio (SMR) for all causes of death was 0.76; that is, after age correction, coalminers have a 24% lower mortality than the general NSW population. Deaths from cancer were lower than expected, and there was a 27% lower mortality from respiratory disease. However, a substantial excess of non-motor-vehicle accidents (SMR, 1.60) was found. Most of these deaths can be attributed to occupation, and some to specific incidents. These excess death rates are confined to underground miners; open cut miners have a substantially lower rate than the general population. CONCLUSIONS: A "healthy worker" effect may explain the lower overall mortality. Although "black lung" is no longer a problem, accidents are still common in underground coalmining. The major expansion of open cut mining in recent years has improved the situation.

Purification and characterization of calmodulin-stimulated protein kinase II from two-day and adult chicken forebrain.

Soluble calmodulin-stimulated protein kinase II has been purified from 2-day and adult chicken forebrain. At both ages the holoenzyme eluted from a Superose-6B column with an apparent molecular weight of approximately 700,000 daltons and contained three subunits. The subunits were found to be the counterparts of the alpha, beta, and beta' subunits of the enzyme purified from adult rat brain in that they had one-dimensional phosphopeptide maps that were indistinguishable from those of the corresponding subunit in the rat enzyme and they migrated in SDS-polyacrylamide gels with the same apparent molecular weights. However, the doublet formed by the beta subunit was much more clearly resolved in the chicken enzyme and the beta' subunit, which was much more abundant in the adult chicken than in the adult rat, was also found to be a doublet. The ratio of the concentrations of the alpha and beta subunits changed during development. By autoradiography following autophosphorylation, the alpha:beta ratios of the 2-day and adult enzymes were 0.89 +/- 0.07 and 1.92 +/- 0.26, respectively; by silver staining the alpha:beta ratios were 0.95 +/- 0.11 and 1.85 +/- 0.17, respectively. The concentration of the beta' subunit was equal to that of the beta subunit at both ages. Autophosphorylation produced a decrease in the electrophoretic mobility of the alpha and beta subunits in SDS-polyacrylamide gels and a marked decrease in the calcium dependence of the substrate phosphorylation activity of the enzyme at both ages. The purified enzyme from chicken brain appeared to be more stable under standard in vitro assay conditions than the rat enzyme, and this was particularly so for the enzyme from 2-day forebrain.

Two developmentally regulated isoenzymes of calmodulin-stimulated protein kinase II in rat forebrain.

Soluble calmodulin-stimulated protein kinase II has been purified from adult and 10-day-old rat forebrain. By autoradiography, the alpha/beta subunit ratios of the 10-day and adult enzymes were 0.67 +/- 0.03 and 2.20 +/- 0.15, respectively. By silver staining, the alpha/beta subunit ratios were 1.02 +/- 0.06 and 2.36 +/- 0.10, respectively. The apparent holoenzyme molecular masses of the purified 10-day and adult enzymes were 500,000 daltons and 700,000 daltons. However, varying the purification conditions revealed higher and lower molecular mass forms at both ages and suggested that the form of the kinase that is usually purified is merely that which has the highest affinity for calmodulin-Sepharose and may not be the form of the kinase that exists in vivo. The subunits of the adult and 10-day enzymes were indistinguishable by one- and two-dimensional electrophoresis and one-dimensional proteolytic peptide maps. These results are consistent with the suggestion that at least two developmentally regulated isoenzymes of this kinase exist in rat forebrain.