Delivery Models and Health Economics of Supportive Care Services in England: A Multicentre Analysis.

AIMS: Improvements in cancer treatment have led to more people living with and beyond cancer. These patients have symptom and support needs unmet by current services. The development of enhanced supportive care (ESC) services may meet the longitudinal care needs of these patients, including at the end of life. This study aimed to determine the impact and health economic benefits of ESC for patients living with treatable but not curable cancer. MATERIALS AND METHODS: A prospective observational evaluation was undertaken over 12 months across eight cancer centres in England. ESC service design and costs were recorded. Data relating to patients' symptom burden were collected using the Integrated Palliative Care Outcome Scale (IPOS). For patients in the last year of life, secondary care use was compared against an NHS England published benchmark. RESULTS: In total, 4594 patients were seen by ESC services, of whom 1061 died during follow-up. Mean IPOS scores improved across all tumour groups. In total, £1,676,044 was spent delivering ESC across the eight centres. Reductions in secondary care usage for the 1061 patients who died saved a total of £8,490,581. CONCLUSIONS: People living with cancer suffer with complex and unmet needs. ESC services appear to be effective at supporting these vulnerable people and significantly reduce the costs of their care.

Ovarian follicle loss in humans and mice: lessons from statistical model comparison.

BACKGROUND: Mammalian oocyte stocks reach maximum size in early development and begin depletion immediately thereafter. This depletion ends women's fertility by midlife. Here we compare five models proposed to characterize human follicular depletion, highlight underlying variation in atresia, and use oocyte counts from laboratory mice to illustrate possible effects of known covariates. METHODS: We compared statistical models, of human data, from five well-known sources and also compared the models' fit to data from four genetically distinct strains of mice. RESULTS: A model first published by Hansen et al. (2008) fit the human data better than any of the alternatives. Best-fit models of oocyte loss in the four strains of mice differed substantially from the best-fit model of the aggregated mouse data. CONCLUSIONS: Although the power model published by Hansen et al. (2008) fit the human data best, Faddy and Gosden's (1996) differential equation model may be a more useful characterization of human follicular atresia. However, these models leave a great deal of variation unexplained. Mouse strain comparisons show that follicle loss in genetically distinct subpopulations can differ substantially from the pattern in the aggregate population. This indicates that differences in follicular stock size between and within populations depend upon more than a single predictor (i.e. age or follicle stocks at previous time points). Our reliance upon data from Western populations represents this study's most important limitation. Expanding data collection to include likely covariates and a wider range of human populations would improve the basis for predicting individual trajectories of follicle loss as more women worldwide opt to delay childbearing and risk aging beyond their own windows of fertility.

African populations and the evolution of human mitochondrial DNA.

The proposal that all mitochondrial DNA (mtDNA) types in contemporary humans stem from a common ancestor present in an African population some 200,000 years ago has attracted much attention. To study this proposal further, two hypervariable segments of mtDNA were sequenced from 189 people of diverse geographic origin, including 121 native Africans. Geographic specificity was observed in that identical mtDNA types are shared within but not between populations. A tree relating these mtDNA sequences to one another and to a chimpanzee sequence has many deep branches leading exclusively to African mtDNAs. An African origin for human mtDNA is supported by two statistical tests. With the use of the chimpanzee and human sequences to calibrate the rate of mtDNA evolution, the age of the common human mtDNA ancestor is placed between 166,000 and 249,000 years. These results thus support and extend the African origin hypothesis of human mtDNA evolution.

Hadza meat sharing.

In most human foraging societies, the meat of large animals is widely shared. Many assume that people follow this practice because it helps to reduce the risk inherent in big game hunting. In principle, a hunter can offset the chance of many hungry days by exchanging some of the meat earned from a successful strike for shares in future kills made by other hunters. If hunting and its associated risks of failure have great antiquity, then meat sharing might have been the evolutionary foundation for many other distinctively human patterns of social exchange. Here we use previously unpublished data from the Tanzanian Hadza to test hypotheses drawn from a simple version of this argument. Results indicate that Hadza meat sharing does not fit the expectations of risk-reduction reciprocity. We comment on some variations of the "sharing as exchange" argument; then elaborate an alternative based partly on the observation that a successful hunter does not control the distribution of his kill. Instead of family provisioning, his goal may be to enhance his status as a desirable neighbor. If correct, this alternative argument has implications for the evolution of men's work.

A third explanation for female infanticide.

PIP: The author presents a critique of some explanations for the distribution of female infanticide across cultures. An alternative hypothesis is proposed that includes elements of sexual selection incorporated into a cultural evolutionary framework^ieng

Language style and evaluation of a female speaker.

This study examined the effect of style of speech ("tentative" vs assertive) used by a female speaker upon the evaluations made by college students. Both men and women evaluated the assertive speaker more favorably than the tentative speaker. The hypothesis that men would devaluate the assertive woman was not supported.

Development of adrenal cortical zonation and expression of key elements of adrenal androgen production in the chimpanzee (Pan troglodytes) from birth to adulthood.

The basis for the pattern of adrenal androgen production in the chimpanzee, which resembles that of humans, is poorly defined. We characterized the developmental zonation and expression of elements of the androgen biosynthetic pathway in the chimpanzee adrenal. The newborn adrenal contained a broad fetal zone (FZ) expressing CYP17, SULT2A1, and Cytochrome B5 (CB5) but not HSD3B; the outer cortex expressed HSD3B but not SULT2A1 or CB5. During infancy, the FZ involuted and the HSD3B-expressing outer cortex broadened. By 3years of age, a thin layer of cells that expressed CB5, SULT2A1, and CYP17 adjoined the medulla and likely represented the zona reticularis; the outer cortex consisted of distinct zonae fasiculata and glomerulosa. Thereafter, the zona reticularis broadened as also occurs in the human. The adult chimpanzee adrenal displayed other human-like characteristics: intramedullary clusters of reticularis-like cells and also a cortical cuff of zona fasiculata-like cells adjoining the central vein.

Depletion of ovarian follicles with age in chimpanzees: similarities to humans.

We retrieved ovarian sections taken from necropsies of 19 captive chimpanzees (Pan troglodytes) aged 0-47 yr, counted the number of primordial follicles in each, and compared the rate of decline in numbers to declines previously documented in humans. The follicular depletion rate in this sample was indistinguishable from that shown across the same ages in classic human data sets. This result supports earlier suggestions that ovarian senescence occurs at the same ages in chimpanzees and humans, implying that the influence of declining ovarian function on other physiologic systems may be distinctively buffered in humans.

The behavioral ecology of modern hunter-gatherers, and human evolution.

Modern day hunter-gatherers are an obvious source of information about human life in the past. But can modern people really tell us anything about other hominids, those represented only in the fossil record? In a world of state governments and a global economy, can present-day foragers even tell us much about life before agriculture? Some behavioral ecologists think so. Their findings show (1) that foraging practices are closely related to the character and distribution of local resources, (2) that men, women and children react to foraging opportunities quite differently, and (3) that sex and age difference in these reactions have important social causes and consequences. Some results directly challenge long-held views about hunter-gatherer economics and social organization, and the scenarios of human evolution based on them.

Hunting income patterns among the Hadza: big game, common goods, foraging goals and the evolution of the human diet.

The assumption that large mammal hunting and scavenging are economically advantageous to hominid foragers is examined in the light of data collected among the Hadza of northern Tanzania. Hadza hunters disregard small prey in favour of larger forms (mean adult mass greater than or equal to 40 kg). Here we report experimental data showing that hunters would reduce their mean rates if they included small animals in the array they target. Still, daily variance in large animal hunting returns is high, and the risk of failure correspondingly great, significantly greater than that associated with small game hunting and trapping. Sharing large kills reduces the risk of meatless days for big game hunters, and obviates the problem of storing large amounts of meat. It may be unavoidable if large carcasses cannot be defended economically against the demands of other consumers. If so, then large prey are common goods. A hunter may gain no consumption advantage from his own big game acquisition efforts. We use Hadza data to model this 'collective action' problem, and find that an exclusive focus on large game with extensive sharing is not the optimal strategy for hunters concerned with maximizing their own chances of eating meat. Other explanations for the emergence and persistence of this practice must be considered.

Male strategies and Plio-Pleistocene archaeology.

Archaeological data are frequently cited in support of the idea that big game hunting drove the evolution of early Homo, mainly through its role in offspring provisioning. This argument has been disputed on two grounds: (1) ethnographic observations on modern foragers show that although hunting may contribute a large fraction of the overall diet, it is an unreliable day-to-day food source, pursued more for status than subsistence; (2) archaeological evidence from the Plio-Pleistocene, coincident with the emergence of Homo can be read to reflect low-yield scavenging, not hunting. Our review of the archaeology yields results consistent with these critiques: (1) early humans acquired large-bodied ungulates primarily by aggressive scavenging, not hunting; (2) meat was consumed at or near the point of acquisition, not at home bases, as the hunting hypothesis requires; (3) carcasses were taken at highly variable rates and in varying degrees of completeness, making meat from big game an even less reliable food source than it is among modern foragers. Collectively, Plio-Pleistocene site location and assemblage composition are consistent with the hypothesis that large carcasses were taken not for purposes of provisioning, but in the context of competitive male displays. Even if meat were acquired more reliably than the archaeology indicates, its consumption cannot account for the significant changes in life history now seen to distinguish early humans from ancestral australopiths. The coincidence between the earliest dates for Homo ergaster and an increase in the archaeological visibility of meat eating that many find so provocative instead reflects: (1) changes in the structure of the environment that concentrated scavenging opportunities in space, making evidence of their pursuit more obvious to archaeologists; (2) H. ergaster's larger body size (itself a consequence of other factors), which improved its ability at interference competition.

Grandmothering, menopause, and the evolution of human life histories.

Long postmenopausal lifespans distinguish humans from all other primates. This pattern may have evolved with mother-child food sharing, a practice that allowed aging females to enhance their daughters' fertility, thereby increasing selection against senescence. Combined with Charnov's dimensionless assembly rules for mammalian life histories, this hypothesis also accounts for our late maturity, small size at weaning, and high fertility. It has implications for past human habitat choice and social organization and for ideas about the importance of extended learning and paternal provisioning in human evolution.

Grandmothering and the evolution of homo erectus.

Despite recent, compelling challenge, the evolution of Homo erectus is still commonly attributed to big game hunting and/or scavenging and family provisioning by men. Here we use a version of the "grandmother" hypothesis to develop an alternative scenario, that climate-driven adjustments in female foraging and food sharing practices, possibly involving tubers, favored significant changes in ancestral life history, morphology, and ecology leading to the appearance, spread and persistence of H. erectus. Available paleoclimatic, environmental, fossil and archaeological data are consistent with this proposition; avenues for further critical research are readily identified. This argument has important implications for widely-held ideas about the recent evolution of long human lifespans, the prevalence of male philopatry among ancestral hominids, and the catalytic role of big game hunting and scavenging in early human evolution.

Demography of the Hadza, an increasing and high density population of Savanna foragers.

This is a report on the demography of the Hadza, a population of East African hunter-gatherers. In it, we describe the results of a census, and our estimation of age structure, survivorship, mean age of women at childbearing, number of live children, total population size and density, and rate of change since 1967. We show that relevant measures fit closely the stable population model North 6 chosen by Dyson to represent Hadza demography in the 1960s. We compare aspects of Hadza demography with surrounding non-Hadza and with the !Kung. Among other things, we find that the Hadza have a higher population density, higher fertility, and a faster population growth rate than do the !Kung. These demographic differences are consistent with our expectations, which were based on differences in the costs and benefits of foraging in the two regions. We also show that Hadza demographic parameters display remarkable consistency over the past 20 years. Since neighboring populations have been encroaching on the area used by the Hadza, and Hadza foragers have been subject to interludes of externally imposed settlement, this consistency is surprising. We discuss some of the implications.

PIP: The research objective was to obtain demographic information of the Hadza, hunter-gatherers from the Eastern Rift Valley, southeast of Lake Eyasi in eastern Africa, in 1985. The aim was to gain insight into their reproductive strategies and how local ecology affects the population. Fertility is assumed to increase where it is more difficult to feed offspring. Comparisons are made to the ]Kung reproductive model. Demographic data were obtained in a 1985 census among 36 camps plus 2 villages in eastern-Hadza-occupied territory in the Eastern Rift Valley. Previous demographic surveys in 1966-67 and 1977 and the Tanzanian Census of 1978 for neighboring populations were important as independent checks on the accuracy of family compositions and age structure. Null hypotheses were tested: that the 1985 data fit the model chosen by Dyson in 1967, or that the data fit the model chosen by Howell for the ]Kung. Data were collected on 1) the age structure of the population, 2) survivorship of people counted in the 1967 census, 3) the mean age of childbearing for mothers of small babies in 1985 and previous censuses, 4) the number of live children/women by age, and 5) calculation of the total population in 1967. 719 eastern Hadza were recorded for 1985 and density was calculated as .30/km squared of .74/sq mile. Density varies locally and with the seasons. With villagers excluded, the density is .24/km squared or .61/sq mile. The methods for constructing the age structure involved fitting a 3-term polynomial regression of individuals of known age against the distribution of all individuals by age rank, and estimating ages of reach rank with a regression equation. The results were not different from the 1967 data; age structure does vary with location. Mortality was closer to Dyson's North 6 stable population model, but very close to Howell's estimates for the ]Kung. The mean age of childbearing was 30.9 years which is later than the ]Kung. The findings support Dyson's conclusions, and reflect higher density, higher fertility (6.15 vs. 4.7), and higher rates of growth than the ]Kung. Bush-living Hadza were even more different from the bush-living ]Kung. A number of explanations for the differences are explored.