In the absence of cancer registry data, is it sensible to assess incidence using hospital separation records?

BACKGROUND: Within the health literature, a major goal is to understand distribution of service utilisation by social location. Given equivalent access, differential incidence leads to an expectation of differential service utilisation. Cancer incidence is differentially distributed with respect to socioeconomic status. However, not all jurisdictions have incidence registries, and not all registries allow linkage with utilisation records. The British Columbia Linked Health Data resource allows such linkage. Consequently, we examine whether, in the absence of registry data, first hospitalisation can act as a proxy measure for incidence, and therefore as a measure of need for service. METHODS: Data are drawn from the British Columbia Linked Health Data resource, and represent 100% of Vancouver Island Health Authority cancer registry and hospital records, 1990–1999. Hospital separations (discharges) with principal diagnosis ICD-9 codes 140–208 are included, as are registry records with ICDO-2 codes C00-C97. Non-melanoma skin cancer (173/C44) is excluded. Lung, colorectal, female breast, and prostate cancers are examined separately. We compare registry and hospital annual counts and age-sex distributions, and whether the same individuals are represented in both datasets. Sensitivity, specificity and predictive values are calculated, as is the kappa statistic for agreement. The registry is designated the gold standard. RESULTS: For all cancers combined, first hospitalisation counts consistently overestimate registry incidence counts. From 1995–1999, there is no significant difference between registry and hospital counts for lung and colorectal cancer (p = 0.42 and p = 0.56, respectively). Age-sex distribution does not differ for colorectal cancer. Ten-year period sensitivity ranges from 73.0% for prostate cancer to 84.2% for colorectal cancer; ten-year positive predictive values range from 89.5% for female breast cancer to 79.35% for prostate cancer. Kappa values are consistently high. CONCLUSION: Claims and registry databases overlap with an appreciable proportion of the same individuals. First hospital separation may be considered a proxy for incidence with reference to colorectal cancer since 1995. However, to examine equity across cancer health services utilisation, it is optimal to have access to both hospital and registry files

Predicting Successful Treatment Outcome of Web-Based Self-help for Problem Drinkers: Secondary Analysis From a Randomized Controlled Trial

BACKGROUND: Web-based self-help interventions for problem drinking are coming of age. They have shown promising results in terms of cost-effectiveness, and they offer opportunities to reach out on a broad scale to problem drinkers. The question now is whether certain groups of problem drinkers benefit more from such Web-based interventions than others. OBJECTIVE: We sought to identify baseline, client-related predictors of the effectiveness of Drinking Less, a 24/7, free-access, interactive, Web-based self-help intervention without therapist guidance for problem drinkers who want to reduce their alcohol consumption. The intervention is based on cognitive-behavioral and self-control principles. METHODS: We conducted secondary analysis of data from a pragmatic randomized trial with follow-up at 6 and 12 months. Participants (N = 261) were adult problem drinkers in the Dutch general population with a weekly alcohol consumption above 210 g of ethanol for men or 140 g for women, or consumption of at least 60 g (men) or 40 g (women) one or more days a week over the past 3 months. Six baseline participant characteristics were designated as putative predictors of treatment response: (1) gender, (2) education, (3) Internet use competence (sociodemographics), (4) mean weekly alcohol consumption, (5) prior professional help for alcohol problems (level of problem drinking), and (6) participants' expectancies of Web-based interventions for problem drinking. Intention-to-treat (ITT) analyses, using last-observation-carried-forward (LOCF) data, and regression imputation (RI) were performed to deal with loss to follow-up. Statistical tests for interaction terms were conducted and linear regression analysis was performed to investigate whether the participants' characteristics as measured at baseline predicted positive treatment responses at 6- and 12-month follow-ups. RESULTS: At 6 months, prior help for alcohol problems predicted a small, marginally significant positive treatment outcome in the RI model only (beta = .18, P = .05, R(2) = .11). At 12 months, females displayed modest predictive power in both imputation models (LOCF: beta = .22, P = .045, R(2) = .02; regression: beta = .27, P = .01, R(2) = .03). Those with higher levels of education exhibited modest predictive power in the LOCF model only (beta = .33, P = .01, R(2) = .03). CONCLUSIONS: Although female and more highly educated users appeared slightly more likely to derive benefit from the Drinking Less intervention, none of the baseline characteristics we studied persuasively predicted a favorable treatment outcome. The Web-based intervention therefore seems well suited for a heterogeneous group of problem drinkers and could hence be offered as a first-step treatment in a stepped-care approach directed at problem drinkers in the general population

[en] PHOTOPLASTICITY BEHAVIOR OF POLYESTER RESINS UNDER AND AFTER LOADING

The Mesoarchean Nuasahi chromite deposits of the Singhbhum Craton in eastern India consist of a lower chromite-bearing ultramafic unit and an upper magnetite-bearing gabbroic unit. The ultramafic unit is a ~5 km long and ~400 m wide linear belt trending NNW-SSE with a general north-easterly dip. The chromitite ore bodies are hosted in the dunite that is flanked by the orthopyroxenite. The rocks of the ultramafic unit including the chromitite crystallized from a primitive boninitic magma, whereas the gabbro unit formed from an evolved boninitic magma. A shear zone (10-75 m wide) is present at the upper contact of the ultramafic unit. This shear zone consists of a breccia comprising millimeter- to meter-sized fragments of chromitite and serpentinized rocks of the ultramafic unit enclosed in a pegmatitic and hybridized gabbroic matrix. The shear zone was formed late synkinematically with respect to the main gabbroic intrusion and intruded by a hydrous mafic magma comagmatic with the evolved boninitic magma that formed the gabbro unit. Both sulfide-free and sulfide-bearing zones with platinum group element (PGE) enrichment are present in the breccia zone. The PGE mineralogy in sulfide-rich assemblages is dominated by minerals containing Pd, Pt, Sb, Bi, Te, S, and/or As. Samples from the gabbro unit and the breccia zone have total PGE concentrations ranging from 3 to 116 ppb and 258 to 24,100 ppb, respectively. The sulfide-rich assemblages of the breccia zone are Pd-rich and have Pd/Ir ratios of 13-1,750 and Pd/Pt ratios of 1-73. The PGE-enriched sulfide-bearing assemblages of the breccia zone are characterized by (1) extensive development of secondary hydrous minerals in the altered parts of fragments and in the matrix of the breccia, (2) coarsening of grain size in the altered parts of the chromitite fragments, and (3) extensive alteration of primary chromite to more Fe-rich chromite with inclusions of chlorite, rutile, ilmenite, magnetite, chalcopyrite, and PGE-bearing chalcogenides. Unaltered parts of the massive chromitite fragments from the breccia zone show PGE ratios (Pd/Ir = 2.5) similar to massive chromitite (Pd/Ir = 0.4-6.6) of the ultramafic unit. The Ir-group PGE (IPGE: Ir, Os, Ru) of the sulfide-rich breccia assemblages were contributed from the ultramafic-chromitite breccia. Samples of the gabbro unit have fractionated primitive mantle-normalized patterns, IPGE depletion (Pd/Ir = 24-1,227) and Ni-depletion due to early removal of olivine and chromite from the primitive boninitic magma that formed the ultramafic unit. Samples of the gabbro and the breccia zone have negative Nb, Th, Zr, and Hf anomalies, indicating derivation from a depleted mantle source. The Cu/Pd ratios of the PGE-mineralized samples of the breccia zone (2.0 × 103-3.2 × 103) are lower than mantle (6.2 × 103) suggesting that the parental boninitic magma (Archean high-Mg lava: Cu/Pd ratio ~1.3 × 103; komatiite: Cu/Pd ratio ~8 × 103) was sulfur-undersaturated. Samples of the ultramafic unit, gabbro and the mineralized breccia zone, have a narrow range of incompatible trace element ratios indicating a cogenetic relationship. The ultramafic rocks and the gabbros have relatively constant subchondritic Nb/Ta ratios (ultramafic rocks: Nb/Ta = 4.1-8.8; gabbro unit: Nb/Ta = 11.5-13.2), whereas samples of the breccia zone are characterized by highly variable Nb/Ta ratios (Nb/Ta = 2.5-16.6) and show evidence of metasomatism. The enrichment of light rare earth element and mobile incompatible elements in the mineralized samples provides supporting evidence for metasomatism. The interaction of the ultramafic fragments with the evolved fluid-rich mafic magma was key to the formation of the PGE mineralization in the Nuasahi massif. © Springer-Verlag 2009.link_to_subscribed_fulltex