Peter Madden

Genetic and environmental contributions to cannabis dependence in a national young adult twin sample

BACKGROUND This paper examines genetic and environmental contributions to risk of cannabis dependence. METHOD Symptoms of cannabis dependence and measures of social, family and individual risk factors were assessed in a sample of 6265 young adult male and female Australian twins born 1964-1971. RESULTS Symptoms of cannabis dependence were common: 11.0% of sample (15.1% of men and 7.8% of women) reported two or more symptoms of dependence. Correlates of cannabis dependence included educational attainment, exposure to parental conflict, sexual abuse, major depression, social anxiety and childhood conduct disorder. However, even after control for the effects of these factors, there was evidence of significant genetic effects on risk of cannabis dependence. Standard genetic modelling indicated that 44.7% (95% CI = 15-72.2) of the variance in liability to cannabis dependence could be accounted for by genetic factors, 20.1% (95% CI = 0-43.6) could be attributed to shared environment factors and 35.3% (95% CI = 26.4-45.7) could be attributed to non-shared environmental factors. However, while there was no evidence of significant gender differences in the magnitude of genetic and environmental influences, a model which assumed both genetic and shared environmental influences on risks of cannabis dependence among men and shared environmental but no genetic influences among women provided an equally good fit to the data. CONCLUSIONS There was consistent evidence that genetic risk factors are important determinants of risk of cannabis dependence among men. However, it remains uncertain whether there are genetic influences on liability to cannabis dependence among women.

Using patients' experiences to identify priorities for quality improvement in breast cancer care: patient narratives, surveys or both?

BackgroundPatients’ experiences have become central to assessing the performance of healthcare systems worldwide and are increasingly being used to inform quality improvement processes. This paper explores the relative value of surveys and detailed patient narratives in identifying priorities for improving breast cancer services as part of a quality improvement process.MethodsOne dataset was collected using a narrative interview approach, (n = 13) and the other using a postal survey (n = 82). Datasets were analyzed separately and then compared to determine whether similar priorities for improving patient experiences were identified.ResultsThere were both similarities and differences in the improvement priorities arising from each approach. Day surgery was specifically identified as a priority in the narrative dataset but included in the survey recommendations only as part of a broader priority around improving inpatient experience. Both datasets identified appointment systems, patients spending enough time with staff, information about treatment and side effects and more information at the end of treatment as priorities. The specific priorities identified by the narrative interviews commonly related to ‘relational’ aspects of patient experience. Those identified by the survey typically related to more ‘functional’ aspects and were not always sufficiently detailed to identify specific improvement actions.ConclusionsOur analysis suggests that whilst local survey data may act as a screening tool to identify potential problems within the breast cancer service, they do not always provide sufficient detail of what to do to improve that service. These findings may have wider applicability in other services. We recommend using an initial preliminary survey, with better use of survey open comments, followed by an in-depth qualitative analysis to help deliver improvements to relational and functional aspects of patient experience.

Predictive value of dysplasia grading and DNA ploidy in malignant transformation of oral potentially malignant disorders.

Dysplasia grading is widely used to assess risk of transformation in oral potentially malignant disorders despite limited data on predictive value. DNA ploidy analysis has been proposed as an alternative. This study examines the prognostic value for both tests used in a routine diagnostic setting to inform clinical management. A retrospective study of conventional dysplasia grading was conducted on 1,401 patients. DNA ploidy analysis was conducted on a subset of 273 patients and results correlated with clinical information, pathologic diagnosis, and outcome over 5 to 15 years. Malignant transformation occurred in 32 of 273 patients (12%) and, of these, 20 (63%) of preexisting index lesions were aneuploid. Of 241 patients not developing carcinoma, only 39 (16%) of index lesions were aneuploid. Epithelial dysplasia correlated with DNA ploidy status (P < 0.001). The overall positive predictive value for malignant transformation by DNA aneuploidy was 38.5% (sensitivity 65.2% and specificity 75%) and by severe dysplasia grade 39.5% (sensitivity 30% and specificity 98%). DNA diploid and tetraploid status had negative predictive value of 90% to 96%. Combining DNA ploidy analysis with dysplasia grading gives a higher predictive value than either technique alone. Each of three traditional dysplasia grades predicts a significantly different risk of carcinoma development and time to transformation. DNA ploidy analysis had equivalent predictive value and also detected additional risk lesions in the absence of dysplasia. Cancer Prev Res; 6(8); 822–31. ©2013 AACR.

Does place of death from cancer vary between ethnic groups in South East England

There is growing evidence that the palliative care needs of certain people, such as those from minority ethnic groups, are not being met. The aim of this study was to investigate whether place of death from cancer differs between ethnic groups. A total of 101,516 patients resident in South East England and who died from lung, colorectal, breast or prostate cancer between 1998 and 2006 were extracted from the Thames Cancer Registry database. Ethnicity data were available for 68,804 patients (68%). The odds ratios (ORs) of death from cancer in a hospice, at home or in hospital were calculated. The results were adjusted for age at death, deprivation, cancer network of residence and time between diagnosis and death. Following adjustment, death in a hospice was significantly less likely for Pakistani patients (OR = 0.47 95% CI [0.30–0.74]), Indian patients (0.68 [0.55–0.84]) and Bangladeshi patients (0.33 [0.19–0.56]). Death at home was significantly less likely in Black African patients (0.48 [0.36–0.65]), Black Caribbean patients (0.78 [0.67–0.90]) and Chinese patients (0.46 [0.28–0.76]). Pakistani, Indian, Bangladeshi, Black African, Black Caribbean and Chinese patients were all significantly more likely than White patients to die in hospital. The results were not substantially altered by recoding the unknown ethnicity group to White or using multiple imputation to assign those with a missing ethnicity an ethnic group. Place of death varies between ethnic groups. This may reflect differences in preferences for place of death or barriers to accessing specialist care in different settings. More detailed prospective qualitative studies are urgently required to determine reasons for this variation.

Using maps and funnel plots to explore variation in place of death from cancer within London, 2002-2007

London has a high proportion of hospital deaths, which health policy seeks to reduce. We explore variation and trends in place of death from cancer within London between 2002 and 2007. Mortality data based on death certificates were used to define deaths from cancer at home, hospice, hospital and nursing home and examine trends over time for London. Proportions of deaths in each place were presented in maps for 31 London primary care trusts (PCTs). Funnel plots were used to identify consistent performance outside the control limits of three standard deviations. There was little overall change in place of death for London, but consistent variation between PCTs. Outer London PCTs had higher proportions of home deaths and inner London PCTs higher proportions of hospice deaths. Funnel plots identified consistent high outlying performance for home, hospice and hospital deaths. No PCT showed a change of 10% or more in home deaths, but five showed decreasing hospital deaths and three increasing hospice deaths. Maps and funnel plots appear useful for identifying areas with differing performance for home, hospital, nursing home and hospice deaths. These methods may help further investigation of how local services may successfully support deaths outside hospital.

Is it possible to determine use of hospice palliative care services by matching hospice and cancer registry data

Population-based studies investigating access to palliative care often use death in a hospice as a proxy for service use. We linked data from a large South London hospice to Thames Cancer Registry (TCR) data to determine whether patients who received hospice services differed from those who did not. We matched hospice data for 2474 cancer patients dying between 2000 and 2006, while resident within a restricted catchment area, to TCR data for residents in this area. During matching 14.2% (n = 352) of hospice patients were excluded due to differing key dates or addresses. In addition, 5.6% (n= 175) of residents initially defined as not receiving hospice services were recorded as dying in a hospice in the TCR dataset. The problems of overlapping catchment areas and of defining patients receiving services meant we could not adequately determine use of hospice services. This method might be applied more successfully to non-urban hospices, primary care trusts or larger regions.