Kinetics of committed and primitive blood progenitor mobilization after chemotherapy and growth factor treatment and their use in autotransplants

Peripheral blood cells (PBCs) collected by leukapheresis after progenitor mobilization with chemotherapy and growth factors have been used successfully to replace marrow autografts in protocols requiring stem-cell support. Moreover, such transplants are often associated with more rapid recovery of blood cell counts than is routinely achieved with bone marrow. While conditions that mobilize colony-forming cells (CFCs) into the circulation are becoming increasingly well characterized, little information is available as to how these or other mobilizing treatments may influence the release of more primitive cells into the peripheral blood. To quantitate the peripheral blood content of such cells, we used the long-term culture-initiating cell (LTC-IC) assay, which detects a cell type that is able to produce progeny CFCs after a minimum of 5 weeks in cultures containing marrow fibroblasts. In this report, we present the findings on 21 patients who were transplanted over a 7-year period at our institution with PBCs alone. PBCs were collected in steady-state (n = 6) or during the recovery phase after high-dose cyclophosphamide (Cy; n = 15, nine with and six without additional growth factor administration). PBCs collected from another 11 patients given granulocyte colony-stimulating factor (G-CSF) were transplanted together with autologous marrow. Time-course studies of nine patients after Cy +/- granulocyte-macrophage CSF (GM-CSF) showed that CD34+ cells, CFCs, and LTC-ICs fell from normal to undetectable levels after Cy, and increased at the time of white blood cell (WBC) recovery: LTC-ICs to a mean of sixfold and CFCs to a mean of 26-fold higher than normal. The mean number of CD34+ cells, CFCs, and LTC-ICs present in the PBC harvest was twofold to 10-fold higher after mobilization than in steady-state collections; however, more than 2-log interpatient variability was observed. After PBC transplantation, the median time to a WBC count more than 10(9)/L was 12 days; polymorphonuclear leukocyte (PMN) count more than 0.5 x 10(9)/L, 15 days; and platelet count more than 20 x 10(9)/L, 17 days, although patients who received fewer than 1.5 x 10(5) CFCs/kg had a more than 50% chance of delayed count recovery (> 28 days). Patients who received Cy + GM-CSF-stimulated PBCs had more rapid and consistent platelet recoveries as compared with other groups receiving Cy mobilized or steady-state PBCs alone, and a rapid WBC recovery after Cy predicted a rapid WBC recovery after transplantation.(ABSTRACT TRUNCATED AT 400 WORDS)

Opinion polling and decision making: a critical appraisal of quality of life assessment

The relationship between quality of life (QOL) assessments and decision making, in relation to the delivery of health services, is subjected to critical appraisal. Three levels of decision making in the health care system are taken into account in the analysis. Criticisms of opinion polling provide the basis for the appraisal. Examples of criticisms considered are: Might the use of QOL information be manipulative? Could the interviews or questionnaires used to obtain QOL data influence personal opinions? Are the methods used sometimes defective and/or superficial? Will QOL information always be used in decision making in ways that are ascertainable and justifiable? It is concluded that the time has come for the main focus of critical appraisal in QOL research to shift, from an emphasis on evaluation of the quality of methods used for assessments of QOL, toward an emphasis on the practical usefulness of QOL data.

Cytokines acting early in human haematopoiesis

In long-term cultures (LTC) of human haematopoietic cells, primitive progenitors termed LTC-initiating cells can be maintained for several months and will differentiate to produce clonogenic cells and mature granulocytes and macrophages when provided with a supportive feeder layer of adherent mesenchymal cells. Primitive haematopoietic cells become associated with this feeder layer and their proliferative status and differentiation are regulated by their interaction with these feeder cells and the growth factors they produce. Both positive and negative regulators are generated in LTC and the balance between these diverse factors is readily manipulated by both direct and indirect mechanisms which appear to operate in a localized fashion. These features parallel those believed to characterize the mechanisms that regulate haematopoiesis in the bone marrow microenvironment in vivo and suggest that further analysis of the LTC system will be useful in delineating the full mystery of this process.

Intensive therapy with cyclophosphamide, carmustine, etoposide +/- cisplatin, and autologous bone marrow transplantation for Hodgkin's disease in first relapse after combination chemotherapy

The optimal timing in which to use intensive chemotherapy and autologous bone marrow transplantation (BMT) in Hodgkin's disease (HD) is uncertain. In 1985, we initiated a program in which this modality was used as the initial salvage therapy in patients relapsing after combination chemotherapy. Fifty-eight patients with HD in first relapse after primary chemotherapy received conditioning with high-dose cyclophosphamide, carmustine, etoposide (VP16-213) +/- cisplatin (CBV +/- P) followed by autologous BMT. All but six of these patients were given a median of two cycles of conventional chemotherapy +/- involved field radiation therapy before CBV +/- P and autologous BMT. These measures were not used as a means for patients selection; all patients receiving such therapy ultimately were transplanted. The probability of nonrelapse mortality, progression of HD, and progression-free survival post-BMT were calculated, and prognostic factors for progression-free survival were evaluated using the Cox proportional hazards method. Treatment-related deaths occurred in only three patients. Thirteen patients have relapsed at a median 0.7 years (range 0.1 to 3.5) post-BMT. At a median follow-up of 2.3 years (range 0.4 to 7.2), the actuarial progression-free survival is 64% (95% confidence interval, 46% to 78%). In the statistical analysis, three similarly weighted but independent prognostic factors were identified: "B" symptoms at relapse, extranodal disease at relapse, and initial remission duration of less than 1 year. Patients with no risk factors had a 3-year progression-free survival of 100%, compared with 81% in patients with one factor, 40% in those with two factors, and 0% in patients with all three factors. CBV +/- P and autologous BMT is highly effective salvage therapy for HD patients in a first relapse, particularly in the subset of patients with less than two adverse factors. Therapy must be improved in the future for patients with > or = 2 adverse factors.

Judging clinical research questions: what criteria are used?

The research question is a crucial aspect of every study. Criteria for the evaluation of the merit of the study question or hypothesis have received surprisingly little attention. A set of non-methodological criteria derived from interviews with 40 researchers (clinical investigators and laboratory scientists) is presented. For both types of researcher, the terms that best described the nature of the criteria included potential impact, justification, feasibility, track record, innovation, intuitive response, aesthetics and politics. The latter three criteria are notably subjective; however all the criteria have an element of non-objectivity. There may well be a reluctance to openly acknowledge that crucial choices about what scientific questions should be explored involve criteria which are themselves not 'objective', and indeed, not even 'scientific'.

Allogeneic bone marrow transplantation for poor-prognosis non-Hodgkin's lymphoma

Twenty-one patients with non-Hodgkin's lymphoma (NHL) felt to be incurable with conventional chemotherapy underwent high-dose chemo +/- radiotherapy and allogeneic sibling donor transplant. The median patient age was 27 years (range 6-47 years); 13 were male and 8 female. By the working formulation, 6 patients at diagnosis had low-grade NHL, 8 intermediate-grade, and 7 high-grade disease. Three patients were in first remission at transplant, 3 in an advanced remission, 5 had failed to respond to initial therapy while 4 had a partial response to initial therapy, and 6 were in relapse (first or beyond). Sixteen patients were conditioned with cyclophosphamide, etoposide and total body irradiation (TBI), 4 with cyclophosphamide and TBI, and one with a combination of busulfan, melphalan and cyclophosphamide. GVHD prophylaxis was variable. At last follow-up, 8 of 21 patients remain alive and progression-free at a median of 37.5 months (range 6-58 months); actuarial event-free survival is 38% (95% confidence interval 17-58%). Thirteen patients died at a median of 2 (range 0.5-8) months post-BMT, 5 from regimen-related toxicity, 3 from acute GVHD, 2 from infections related to chronic GVHD and 3 from disease progression. Factors which were adverse predictors of progression-free survival included low-grade disease, presence of B symptoms at BMT, Karnofsky performance status at BMT and female sex. We concur with previous workers in concluding that allogeneic BMT may offer effective therapy for selected patients with incurable NHL. Major issues to be considered include timing of BMT and disease status at BMT.

Do patients' evaluations of a future health state change when they actually enter that state?

Fundamental to using utilities for future health states for clinical decision analysis is the assumption that the utilities are stable. The purpose of this study was to determine if cancer patients' prior evaluations of a treatment-induced health state remain stable when they later experience that state. Before a four-week course of radiation therapy, 66 laryngeal cancer patients evaluated three common treatment-induced outcome scenarios (mild/moderate/severe) using rating scales and the time trade-off, and provided self-assessments of voice symptoms, voice function, and general health. Evaluations and self-assessments were repeated at the end of therapy, and respondents indicated which outcome scenario described their actual end-of-therapy state. Twenty-four patients identified the mild scenario as their outcome state, 36 the moderate, and 6 the severe. No across-time differences in evaluations were detected, although significant (P < .0001) downward shifts in scores for voice symptoms (t = 5.67), voice function (t = 5.10), and general health (t = 6.69) indicated that actual change in health status had occurred. These results imply that patients' evaluations of imagined short-term health states encountered during radiation therapy for laryngeal cancer remain consistent when those states are experienced at a later time. The design of this project provides a model for determining if this consistency appears in other clinical situations.

A study of diet and breast cancer prevention in Canada: why healthy women participate in controlled trials

Little research has been undertaken to determine why healthy people agree to enroll in randomized controlled trials of cancer prevention. This study describes the beliefs of Canadian women participating in a trial designed to determine the effect of reducing dietary fat on the development of breast cancer. Healthier eating, nutritional counseling, contributing to science, and helping others were the most frequently cited advantages of participation. Weight control and general better health were specifically associated with the dietary regimens. Attending appointments and difficulties when eating out were the main disadvantages of participation. Suggestions that would promote adherence to the trial protocol also were elicited. Responses cited most often included opportunities to meet other participants, more nutritional counseling (particularly psychological tips), updates about the trial, and more recipes. Attention should be paid to these suggestions as they characterize some of the major determinants of adherence behavior.

The elusive peripheral blood hemopoietic stem cell

Long-term culture initiating cells (LTC-IC) are primitive hemopoietic progenitors that give rise to clonogenic cells when provided with a supportive feeder layer of mesenchymal cells. These LTC-IC possess many of the characteristics expected of marrow-repopulating "stem cells" including high proliferative and multilineage-differentiative capacity and resistance to 4-hydroperoxy-cyclophosphamide (4-HC) killing. In addition, stem cells are known to persist and may proliferate in murine LTC, and human marrow grown in LTC has been successfully used as hemopoietic support for myeloablative therapy. LTC-IC, as well as clonogenic precursors, circulate in normal peripheral blood, and the concentration of both progenitor types can be increased by cytotoxic chemotherapy and/or growth factors. When mobilized peripheral blood cells are used as hemopoietic support for high-dose chemo/radiotherapy, engraftment has often been more rapid than that achieved with autologous marrow. Thus, primitive hemopoietic cells circulate in human blood, which can enable hemopoietic reconstitution following aggressive therapy for malignant disease.

Autografting in chronic myeloid leukemia with cultured marrow: update of the Vancouver Study

When chronic myeloid leukemia (CML) marrow is set up in long-term culture (LTC), Philadelphia chromosome (Ph)-positive (Ph+) cells typically decline and Ph-negative (Ph-) hematopoietic cells often become detectable. In 1987, we initiated a study to evaluate the feasibility of using 10-day cultured marrow autografts to allow intensive treatment of CML. Patients were selected on the basis of a previous assessment of the frequencies of normal and leukemic LTC-initiating cells (LTC-IC) remaining in their marrow after 10 days of LTC. Of the 87 patients evaluated, 36 (41%) were considered eligible, and 22 (15 in first chronic phase [CP], Group 1; and 7 with more advanced disease, Group 2) were autografted with 10-day cultured marrow after intensive therapy. Satisfactory hematological recovery occurred in 16 patients, and of these, only Ph- cells were detected in 13 (nine in Group 1), with 76-94% Ph- cells in the other three (two in Group 1). Ph+ cells reappeared between 4 and 36 months post-autograft in all but one of the 13 patients in whom complete (morphological and cytogenetic) remission had been achieved; the remaining patient died in remission. Nine of these twelve patients were then treated with alpha-interferon (IFN-alpha) 1-3 x 10(6) units/m2, 3-7 days/week; four returned to complete remission, three developed increasing numbers of Ph+ cells, and two are still too early to evaluate. Fifteen patients (12 in Group 1) remain alive and well, nine in hematological remission (eight in Group 1), 9 to 64 months (median 28) post-autograft.(ABSTRACT TRUNCATED AT 250 WORDS)

High-dose chemotherapy and autologous bone marrow transplantation for patients with poor prognosis nonseminomatous germ cell tumours

Twenty-one patients with poor prognosis nonseminomatous germ cell tumours (six with extreme burden disease at presentation in whom partial remission had been achieved with initial induction therapy, and 15 with recurrent disease after induction therapy) were treated with high-dose chemotherapy and autologous bone marrow transplantation (BMT). The first six received etoposide 3.0 g m-2, ifosfamide 6.0 g m-2 and carboplatin 1.2 g m-2 (Regimen 1), and the subsequent 15 received etoposide 2.4 g m2 (continuous infusion), cyclophosphamide 7.2 g m-2 and carboplatin 0.8 g m-2 (Regimen 2) followed by infusion of previously stored autologous marrow. Regimen 1 was associated with considerable renal toxicity and mucositis, whereas Regimen 2 was relatively well tolerated. Two patients died as a consequence of the treatment: one of candidemia and one of interstitial pulmonary fibrosis. Only one of 17 patients who were autografted in or approaching marker remission subsequently developed disease progression (event-free survival 82%, 95% confidence interval [CI] 55% to 94%), whereas all four patients who had progressive disease at autografting subsequently developed further disease progression and died. Fourteen patients remain well and free of disease 0.5 to 6.5 years (median 3.3) post-BMT (event-free survival 67%, 95% CI 43% to 83%). A strategy of prompt reinduction followed by high-dose chemotherapy and autologous BMT at the first sign of failure of standard therapy may allow cure to be a realistic expectation.

Quality of life assessments and levels of decision making: differentiating objectives

The purpose of this paper is to examine uses of quality of life (QOL) measurements at different levels of decision making within the health care system, ranging from the micro (clinical) level, through the meso (agency, institutional or regional) level to the macro and meta (governmental) levels. We use individualized, group and population-based QOL and preference assessments as illustrative examples of ways in which QOL information and decision making level interact. We conclude that the meso and macro levels pose particularly challenging problems, and suggest that, if the primary emphasis is placed on applications of QOL assessments at the micro (clinical) level of decision making, a research agenda that is much too limited may be adopted.

Growth factor regulation of the maintenance and differentiation of human long-term culture-initiating cells (LTC-IC)

Current evidence suggests that the most primitive of hematopoietic progenitors detectable in adult human marrow are cells that can give rise to clonogenic cells for > 5 weeks in vitro when co-cultured with certain stromal cells. Procedures developed to isolate these so-called long-term culture-initiating cells (LTC-IC) in highly purified form allow their separation from most other hematopoietic cells as well as from stromal cells and their precursors also present in the marrow. We have used such procedures in conjunction with the LTC system to identify specific growth factors that support human LTC-IC maintenance and differentiation and to make comparisons with effects on later events in hematopoiesis. In some studies, soluble growth factors were added exogenously to the study cultures. In others, marrow-derived fibroblasts were genetically engineered to allow increased levels of specific human growth factors to be endogenously produced. In both of these ways, the influence of granulocyte--macrophage colony-stimulating factor (GM-CSF), G-CSF, Interleukin-3 (IL-3), IL-6, and Steel factor were investigated. Increased provision of GM-CSF alone (or in combination with other factors) enhanced terminal cell differentiation (production of granulocytes and macrophages), although the same conditions had no influence on LTC-IC differentiation (production of clonogenic cells) or on LTC-IC maintenance. In contrast, G-CSF, IL-3 and IL-6 alone (and more so when combined) in the presence of feeders effectively enhanced LTC-IC differentiation and was less active on later stages of granulopoiesis. Provision of additional exogenous Steel factor also enhanced LTC-IC differentiation, although Steel factor alone, without feeders or other growth factors, did not support either the initial differentiation of LTC-IC into clonogenic cells or their subsequent differentiation into mature granulocytes and macrophages. No combination of exogenously added growth factors was found that enhanced LTC-IC maintenance over that achieved with primary marrow feeders. However, some murine fibroblasts (including those of SI/SI origin), as well as certain exogenous growth factors (including Steel factor), were able to substitute for feeders in this regard. These observations highlight the likelihood of redundancy in factors that can elicit similar biological responses at the earliest as well as later stages of hematopoietic cell development. Nevertheless, it appears that the responses of hematopoietic cells at different stages of differentiation to any particular factor may differ markedly and that the nature of any particular response is not yet predictable from a knowledge of effects on earlier or later cell types.

Alternative mechanisms with and without steel factor support primitive human hematopoiesis

As a first approach to defining the molecular requirements for supporting human hematopoietic stem cell maintenance and differentiation in vitro, we have analyzed and compared the ability of various factors to support the maintenance and initial differentiation of human long-term culture-initiating cells (LTC-ICs), a distinct, rare primitive hematopoietic cell type whose progeny after 5 weeks include cells detectable as colony-forming cells. Normal human marrow cells highly enriched in LTC-ICs (approximately 1% pure) were placed in cultures containing either preestablished, irradiated human marrow adherent feeder layers, or feeders consisting of Steel factor-deficient SI/SI, or normal +/+ murine fibroblasts, or no feeders. In some groups, either Steel factor alone, granulocyte colony-stimulating factor (G-CSF) and interleukin-3 (IL-3), or all three factors combined were also added repeatedly. SI/SI murine fibroblasts were equivalent to +/+ controls and to normal human marrow feeders in supporting both LTC-IC maintenance and clonogenic cell output over a 5-week period. Soluble Steel factor alone could, however, effectively substitute for human marrow feeders to support LTC-IC maintenance, although clonogenic cell output was markedly reduced under these conditions. Conversely, soluble Steel factor with G-CSF and IL-3 or with feeders (or all together) did not further enhance (or depress) LTC-IC maintenance, although under these conditions clonogenic cell output was markedly increased. These findings confirm previous evidence that LTC-IC maintenance and clonogenic cell production are differentially regulated and show for the first time that LTC-IC maintenance can be supported by different nonsynergizing factors that may, but need not, include Steel factor.

Induction therapy for acute myelogenous leukemia in patients over 60 years with intermediate-dose cytosine arabinoside, mitoxantrone and etoposide

Twenty-three patients greater than age 60 years with acute myelogenous leukemia (AML) received induction therapy with continuous infusion cytosine arabinoside (1.5 g/m2/day, day 1-3), mitoxantrone (10 mg/m2/day, day 1-3) and etoposide (800 mg/m2, day 4). Patients entering complete remission (CR) were eligible to receive an identical consolidation cycle. Eighteen of the 23 patients (78%; 95% confidence interval 56% to 93%) entered CR. Twelve of these received consolidation therapy and 4 of these remain in remission at 3 to 20 months. Hematologic toxicity of the regimen was acceptable; only 1 patient died following therapy (having attained a CR). Non-hematologic toxicity was mostly mild (grade 2 or less) with one episode of grade 3 cerebellar toxicity. While this regimen induces a high CR rate in patients > age 60 years, relapses remain common and overall survival is too early to assess.

Treatment of multiple myeloma with intensive chemotherapy followed by autologous BMT using marrow purged with 4-hydroperoxycyclophosphamide

In August 1988 we began a program in which multiple myeloma patients achieving < or = 10% marrow plasma cells and > or = 50% reduction in paraprotein levels after the VAD (vincristine, doxorubicin, dexamethasone) regimen underwent bone marrow harvest, ex vivo marrow purging with 4-hydroperoxycyclophosphamide (4-HC) and marrow cryopreservation. Conditioning with a regimen of high-dose busulfan (total dose 16 mg/kg), cyclophosphamide (120 mg/kg) and melphalan (90 mg/m2) (BU + CY + MEL) followed by autologous BMT was then carried out. Seventeen of the 24 patients who received VAD (71%, 95% confidence interval [CI] 49 to 87%) were eligible for bone marrow harvest. One patient was not harvested because of non-medical reasons; two patients who underwent marrow harvest had gross plasmacytosis present in biopsies performed intraoperatively and did not undergo BMT. Fourteen patients (58%, 95% CI 37 to 78%) received BU + CY + MEL and 4-HC-purged autologous BMT. The median time to recovery of 0.5 x 10(9)/l neutrophils was 19 days (range 14 to 26) while the last platelet transfusion was given on a median of day 32 (range 10 to 46) post-BMT in the evaluable patients. The major non-hematologic toxicity was hepatic; two patients in complete remission died of hepatic veno-occlusive disease. Another patient succumbed to fungal infection despite neutrophil recovery. The remaining 11 patients achieved responses (complete in six and partial in five) associated with a normal performance status.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of nonmedical factors on family physicians' decisions about referral for consultation

OBJECTIVES

To identify nonmedical factors perceived by family physicians (FPs) and consultants as important influences on decisions about referral for consultation, to determine the relative frequency with which such factors are cited and to identify those factors ranked as most important by the FPs and consultants.

DESIGN

Survey with semistructured interview between July 1989 and April 1990.

PARTICIPANTS

A total of 41 FPs and 20 consultants who were practising or had practised previously in Nova Scotia.

INTERVENTIONS

The questionnaire comprised 10 questions: 4 were nondirective "probes" designed to elicit responses without suggesting possible answers, 2 asked the participants to rank such responses in order of importance, and 4 were "prompts" that asked for comments about a list of factors based on a review of the literature.

RESULTS

A total of 4845 discrete items were mentioned as being capable of influencing FPs' decisions about referral for consultation. Aggregation of related items resulted in a list of 35 nonmedical factors, of which 11 were identified by at least half the respondents and 14 by less than half but more than 10. These 25 factors fell into three categories: patient and family factors (e.g., patient's wishes), FP and consultant factors (e.g., FP's capabilities), and other influences (e.g., style of practice). On the basis of both frequency of identification and priority scores "patient's wishes" emerged as the most important factor. Two medical factors that were consistently cited--type of problem and age of patient--were thought to interact with the other factors.

CONCLUSION

Certain nonmedical considerations may substantially affect physicians' referral practices.

Retroviral gene transfer to primitive normal and leukemic hematopoietic cells using clinically applicable procedures

Clinical uses of gene transfer to bone marrow transplants require the establishment of a reproducible method for infecting large numbers of very primitive hematopoietic cells at high efficiency using cell-free retrovirus-containing media. In this study we report the results of experiments with preparations of a high-titer (2-5 x 10(7)/ml) helper-free recombinant neo(r) retrovirus that indicate this goal can now be achieved based on measurements of gene transfer efficiencies to cells referred to as long-term culture initiating cells (LTC-IC) because they give rise to clonogenic cells after greater than or equal to 5 wk in long-term culture (LTC). Intermittent, repeated exposure of normal human marrow mononuclear cells to virus-containing supernatant over a 3-d period of cell maintenance on an IL-3/granulocyte colony-stimulating factor (G-CSF) producing stromal layer resulted in gene transfer efficiencies to LTC-IC of 41%; a level previously obtainable only using co-cultivation infection techniques. Marrow cells enriched greater than or equal to 500-fold for LTC-IC (1-2% pure) by flow cytometry showed gene transfer efficiencies of 27% when infected in a similar fashion over a shorter period (24 h), but in the presence of added soluble IL-3 and G-CSF without stromal feeders, and this increased to 61% when Steel factor was also present during the infection period. By using a less highly enriched population of LTC-IC obtained by a bulk immunoselection technique applicable to large-scale clinical marrow harvests, gene transfer efficiencies to LTC-IC of 40% were achieved and this was increased to 60% by short-term preselection in G418. Southern analysis of DNA from the nonadherent cells produced by these LTC over a 6-wk period provided evidence of clonal evolution of LTC-IC in vitro. Leukemic chronic myelogenous leukemia LTC-IC were also infected at high efficiency using the same supernatant infection strategy with growth factor supplementation. These data demonstrate the feasibility of using cell-free virus preparations for infecting clinical marrow samples suitable for transplantation, as well as for further analysis of human marrow stem cell dynamics in vitro.

Is there a role for preference assessments in research on quality of life in oncology?

The development of ways to evaluate interventions that may have an impact on quality of life is a rapidly-developing area of research in clinical oncology, especially within the context of randomized controlled trials. We propose a role for assessments of preferences in such evaluations, including preference studies designed to assess attitudes toward the clinical acceptability of interventions, and preference trials designed to assess choice behaviour in relation to interventions. We suggest that such preference assessments represent a specific case of a more general issue: the need to develop an 'ethics of evidence', that is, standards for the creation, assessment and communication of evidence. We then outline a framework within which an 'ethics of evidence' might be developed, and suggest that the framework also may provide a useful model for the processes involved in the transfer of research results into clinical practice. As an illustration, we consider the problem of decision making in circumstances where the choice of therapy depends primarily on the patient's own preferences, as, for example, in the choice of mastectomy or breast-conserving treatment in early-stage breast cancer. The long-term goal is to develop criteria which might be used to foster shared rational decision making in such circumstances.

Collection of peripheral blood mononuclear cells as a byproduct of plateletpheresis with two different blood cell separators

Peripheral blood mononuclear cells (PBMC) were collected as a byproduct of plateletpheresis of normal blood cell donors using modifications to standard automated protocols on either the CS-3000 or Spectra blood cell separator machine. Comparison of the PBMC products obtained showed X +/- SD WBC yields of 5.3 +/- 3.4 vs. 3.8 +/- 2.0 x 10(9) with the CS-3000 and Spectra, respectively (P < .0001). The majority of the cells were lymphocytes, with 13-15% monocytes with both machines. Sixteen percent of the WBC collected with the Spectra, but only 1% of those collected with the CS-3000, were granulocytes. The CS-3000 PBMC product contained fewer RBC (0.2 +/- 0.1 x 10(11) vs. 2.4 +/- 0.6 x 10(11)) and more platelets (1.6 +/- 0.6 x 10(11) vs. 0.35 +/- 0.39 x 10(11)) in a smaller volume (40 +/- 14 ml vs. 229 +/- 37 ml) than the Spectra products. Comparison of the platelet collections harvested when PBMC were also collected to platelets harvested using standard procedures on the same machine showed no change in platelet, WBC, or RBC yields for the Spectra. A significant increase in mean WBC contamination from 40 +/- 56 x 10(7) to 112 +/- 205 x 10(7) and a small, but statistically insignificant, decrease in platelet yield from 4.1 +/- 1.2 x 10(11) to 3.9 +/- 1.8 x 10(11) was observed in the CS-3000 platelet collections when PBMC were harvested. There was no sustained change in donor lymphocyte counts and no change in acute donor side effects or time requirements when PBMC were collected.(ABSTRACT TRUNCATED AT 250 WORDS)

The human hematopoietic stem cell in vitro and in vivo

A quantitative assay for a primitive human hematopoietic cell has been developed. The cell identified has been assigned the operational designation of long-term culture (LTC)-initiating cell based on its ability when cultured on supportive fibroblast monolayers to give rise to daughter cell(s) detectable by standard in vitro colony assays. Three lines of evidence support the view that the LTC-initiating cell assay may allow the relatively specific enumeration of totipotent cells with in vivo reconstituting potential. These involve the demonstration: (1) that conditions in analogous murine long-term cultures stimulate the extensive amplification (self-renewal) of some totipotent long-term repopulating cells, (2) that most of the LTC-initiating cells in normal human bone marrow are phenotypically different from most of the colony-forming cells present in the same cell suspensions in their possession of a number of characteristics specifically associated with transplantable stem cells; and (3) that cultured marrow cells from patients with chronic myeloid leukemia which, after maintenance under LTC conditions for 10 days contain some normal LTC-initiating cells but no detectable leukemic LTC-initiating cells, can after autografting reconstitute the hematopoietic system with normal cells.

Comparison of search strategies on CD Plus/MEDLINE

OBJECTIVE

To compare two strategies for searching MEDLINE using the CD Plus/MEDLINE program on compact disc.

DESIGN

Comparison study.

INTERVENTIONS

Two search strategies were designed and executed for each of two topics (patient recruitment to clinical trials and attitudes of patients, the public and health care professionals toward clinical trials). Strategy A: searches based on key words selected from the medical subject heading (MeSH) tree structure. Strategy B: searches based on MeSH terms most frequently used to index a known set of relevant articles. Defined search restrictions were then applied. The effects of the restrictions on the absolute number of citations retrieved and on the proportion of relevant citations were assessed.

OUTCOME MEASURES

Number of articles retrieved, number of relevant articles, precision and recall of each search strategy and overlap between strategies.

MAIN RESULTS

Strategy A produced more citations than strategy B (recruitment 147 v. 38, attitude 366 v. 57) but had more inappropriate citations (recruitment 75 v. 17, attitude 265 v. 25). Both strategies produced 73 relevant recruitment citations and 101 relevant attitude citations. In the recruitment search although the precision did not differ significantly between strategies A and B the difference in recall was significant (98.6% v. 28.8% respectively, p less than 0.0001). In the attitude search strategy A had a lower precision than strategy B (27.6% v. 56.1%, p less than 0.0001) but a much higher recall (100% v. 31.7%, p less than 0.0001).

CONCLUSIONS

Strategy A would be more valuable to researchers doing extensive reviews, whereas strategy B would be useful for the busy clinician who simply wants a few appropriate references quickly and is willing to sacrifice comprehensive retrieval in the interest of efficiency.

Differential regulation of primitive human hematopoietic cells in long-term cultures maintained on genetically engineered murine stromal cells

Various growth factors are known to stimulate both early and late stages of human hematopoietic cell development in semisolid assay systems, but their role as microenvironmental regulators is poorly understood. To address this problem, we developed a novel coculture system in which highly purified primitive human hematopoietic cells were seeded onto an irradiated feeder layer of cells from a murine marrow-derived stromal cell line (M2-10B4) previously engineered by retroviral-mediated gene transfer to produce specific human factors. Effects on cells at very early, intermediate, and late stages of hematopoiesis were then evaluated by assessing the number of clonogenic cell precursors (long-term culture initiating cells [LTC-IC]), clonogenic cells, and mature granulocyte and macrophage progeny present in the cultures after 5 weeks. In the absence of any feeders, cells at all stages of hematopoiesis decreased to very low levels. In contrast, maintenance of LTC-IC was found to be supported by control murine stromal cells as effectively as by standard human marrow adherent layers. The presence of granulocyte colony-stimulating factor (G-CSF) and interleukin-3-producing M2-10B4 cells in combination was able to further enhance the maintenance and early differentiation of these cells without a decline in their proliferative potential as measured by the clonogenic output per LTC-IC. However, this effect was lost if granulocyte-macrophage CSF (GM-CSF)-producing feeders were also present. On the other hand, in the presence of GM-CSF-producing feeders, the output of mature granulocytes and macrophages increased 20-fold. These findings show that it is possible to selectively improve the maintenance of very primitive human hematopoietic cells in vitro or their output of mature progeny by appropriate manipulation of the long-term marrow culture system. Further exploitation of this approach should facilitate investigation of the mechanisms operative within the human marrow microenvironment in vivo and the design of protocols for in vitro manipulation of human marrow for future therapeutic applications.

Benign and malignant breast disease: the relationship between women's health status and health values

The study purpose was to determine whether differences in the weights assigned to various dimensions of health by 90 women in three subgroups (benign breast disease, breast cancer receiving chemotherapy, and breast cancer receiving other therapies) were associated with differences in self-reported health status in these dimensions. Two methods, one direct and the other indirect, were used to elicit values for mobility, depression, and social support. Two different scales also provided self-reports of health status in each of these dimensions. These measures, in conjunction with sociodemographic variables, were used to test for status-value relationships. No statistically significant association between health values and health status was observed. The absence of any detectable association may have been a result of methodologic difficulties in assessing broadly defined dimensions of health. A possible solution would be to use "individualized" dimensions that are uniquely important to the individual, and to take into account such factors as possible influences of past health status and values, and possible gaps between expected health status and health status actually experienced.

Molecular analysis of primitive hematopoietic cell proliferation control mechanisms

Cells at two distinct early stages in the development of mature human blood cells from primitive totipotent hematopoietic stem cells can now be defined and quantitated by separate in vitro assays. Current evidence suggests that most, if not all, colony-forming cells--that is, cells that give rise to colonies of mature progeny within one to three weeks in semisolid culture systems, represent an intermediate stage of hematopoietic progenitor. These cells are not self-sustaining; if they are used to initiate hematopoiesis on competent marrow stromal layers, they rapidly disappear as they differentiate or die. However, clonogenic cells can be generated in such cultures from another cell type over a period of four to eight weeks. We have, therefore, assigned the term long-term culture initiating cell (LTC-IC) to this latter type of clonogenic precursor cell. The production and differentiation of cells in both of these compartments in LTC are dependent on, and regulated by, nonhematopoietic "stromal" cells that form a heterogeneous adherent layer in which close-range interactions with hematopoietic cells take place. The use of separate endpoints to monitor the maintenance, differentiation, and reversible activation or arrest of cycling of these cells has recently revealed different molecular mechanisms regulating their respective functions. However, an important common feature appears to be the relative local concentration of positive and negative regulators to which the target hematopoietic cell is exposed. Both gene expression and growth factor release measurements as well as results obtained using genetically engineered stroma and repeated soluble growth factor addition implicate G-CSF as an endogenous positive regulator of primitive hematopoietic cells. Similarly, gene expression, factor production, factor addition, and neutralizing antibody experiments implicate TGF-beta as an endogenous inhibitor of primitive hematopoietic cells.

Separation of functionally distinct subpopulations of primitive human hematopoietic cells using rhodamine-123

Normal human bone marrow (BM) contains a small population of cells that can give rise to clonogenic progenitors after 5 weeks in long-term culture (LTC). We have previously shown that these LTC-initiating cells (LTC-IC) differ from the majority of directly clonogenic cells with respect to both light-scattering properties and surface antigen expression. In this paper we show that virtually all LTC-IC (94%) are among the 3%-5% of light-density marrow cells that take up relatively low amounts of rhodamine-123 (Rh-123). In contrast, only 70% of erythroid burst-forming units (BFU-E) and 40% of granulocyte-macrophage colony-forming units (CFU-GM) are recovered in the Rh-123-dull fraction. In addition, we have found that double staining of marrow with Rh-123 and phycoerythrin-labeled anti-CD34 antibodies allows the CD34+ cells to be divided into two subpopulations, of which, on average, 35% are Rh-123-dull. Isolation of these CD34+ Rh-123-dull cells thus provides a single-step enrichment of approximately 240-fold in LTC-IC by comparison to the light-density (less than 1.077 g/cm3) fraction of normal BM. This represents an overall enrichment in LTC-IC of approximately 1000-fold. As expected from the results of staining with Rh-123 only, the majority of directly clonogenic cells are present in the CD34+ Rh-123-bright fraction, where they are enriched approximately 40-fold over their concentration in the light-density fraction. These results indicate marked differences in Rh-123 uptake between subsets of primitive human hematopoietic cells currently defined by different functional assays and suggest that RH-123 staining will be useful for the further purification and analysis of these cells.

Communicating probabilistic information to cancer patients: is there 'noise' on the line?

The objective was to examine the way that cancer patients translate verbal descriptors of probability into numerical estimates. A list of words commonly used on consent forms to describe the likelihood for benefits or risks of therapies was provided to 100 cancer patients. Two formats, paper/pencil or computer, were used to provide the list of words. Two methods, magnitude estimation and linear analogue scaling, were used to obtain probability estimates for each word. In addition, two scenarios were developed to study 'context effects' on numerical interpretations of verbal descriptions of probability. All patients provided numerical values for the words on two occasions, separated by one week, and two interviewers collected the data. Regardless of method or format, each word elicited widely variable numerical interpretations. An ANOVA model, including patient, word, interviewer, time, method and format, indicated that patient and interviewer produced major effects on probability estimates. Agreement between methods and across time was good. Paper/pencil and computer formats yielded similar results. Context effects did not appear to influence the numerical probabilities elicited by the 2 scenarios. It was concluded that, within this group of patients, there was no consensus about numerical meaning of a given word, and that interviewers can systematically influence numerical interpretations. There appears to be a great deal of 'noise' in this particular line of communication between patients and health professionals.

Are we getting informed consent from patients with cancer?

We developed a consent form for a hypothetical trial and asked patients to underline information that was pertinent to their decision to accept or refuse to participate in the proposed trial. We also investigated whether patients correctly interpreted statements describing the probability of certain events occurring. Of the 50 patients, 74% did not indicate that both risks and benefits were pertinent. Of the 20 patients who would not enter the trial, 70% focused on risks of therapy only. In contrast, of the 30 who agreed to enter, only 33% focused entirely on risks, while 10% did not note potential for either benefit or risk. For each of four probability statements, patients chose one of four possible interpretations, only one of which was correct. Depending on the statement, between 26 and 54% of the interpretations were incorrect. It appears that many decisions regarding trial entry may be based upon incomplete or incorrect information.

Selective expression of CD45 isoforms on functional subpopulations of CD34+ hemopoietic cells from human bone marrow

We have found that the small population of cells in human marrow that are characterized by their expression of CD34 can be readily subdivided into two apparently nonoverlapping subpopulations of approximate equal size, one expressing CD45RO and one CD45R. Functional studies of these subpopulations revealed that all of the primitive erythroid colony-forming cells (BFU-E) are CD34+ CD45RO+. Similarly, more primitive cells that give rise to both erythroid and granulopoietic colony-forming cells after being maintained for 5 wk on confluent irradiated long-term marrow culture feeder layers, also show this phenotype. In contrast, most granulopoietic colony-forming cells are CD34+ CD45RO- cells. The differential expression of CD45 isoforms on distinct functional subpopulations of hemopoietic cells is consistent with the concept that these molecules play an important role in the differentiation or activation of primitive, normally quiescent, hemopoietic cells. The presence of CD45RO and the lack of CD45R on human cells capable of initiating hemopoiesis in the long-term marrow culture system correspond to the reported lack of CD45R on transplantable hemopoietic stem cells in rodents and may be a useful addition to strategies for human stem cell purification, or for purging CD45R+ leukemic cells.

Functional characterization of individual human hematopoietic stem cells cultured at limiting dilution on supportive marrow stromal layers

A major goal of current hematopoiesis research is to develop in vitro methods suitable for the measurement and characterization of stem cells with long-term in vivo repopulating potential. Previous studies from several centers have suggested the presence in normal human or murine marrow of a population of very primitive cells that are biologically, physically, and pharmacologically different from cells detectable by short-term colony assays and that can give rise to the latter in long-term cultures (LTCs) containing a competent stromal cell layer. In this report, we show that such cultures can be used to provide a quantitative assay for human "LTC-initiating cells" based on an assessment of the number of clonogenic cells present after 5-8 weeks. Production of derivative clonogenic cells is shown to be absolutely dependent on the presence of a stromal cell feeder. When this requirement is met, the clonogenic cell output (determined by assessment of 5-week-old cultures) is linearly related to the input cell number over a wide range of cell concentrations. Using limiting dilution analysis techniques, we have established the frequency of LTC-initiating cells in normal human marrow to be approximately 1 per 2 X 10(4) cells and in a highly purified CD34-positive subpopulation to be approximately 1 per 50-100 cells. The proliferative capacity exhibited by individual LTC-initiating cells cultured under apparently identical culture conditions was found to be highly variable. Values for the number of clonogenic cells per LTC-initiating cell in 5-week-old cultures ranged from 1 to 30 (the average being 4) with similar levels being detected in positive 8-week-old cultures. Some LTC-initiating cells are multipotent as evidenced by their generation of erythroid as well as granulopoietic progeny. The availability of a system for quantitative analysis of the proliferative and differentiative behavior of this newly defined compartment of primitive human hematopoietic cells should facilitate future studies of specific genetic or microenvironmental parameters involved in the regulation of these cells.

Whose utilities for decision analysis?

The goal of this study was to examine sources of variation in the utilities assigned to health states. The authors selected a common clinical problem, carcinoma of the rectum, and examined the utilities assigned to colostomy, a common outcome of treatment for that disease. After preparing and validating a description of colostomy and its effects on patients' lives, utilities for the state were obtained from five groups of individuals. These comprised two groups of patients who received treatment for rectal cancer, a group of physicians and surgeons specializing in the treatment of this disease, and two groups of healthy subjects, none of whom were health professionals. Of the patients who had been treated for rectal cancer, one group had been treated surgically with the formation of colostomies and the other had been treated with radiotherapy and none had a colostomy. Utilities for colostomy were elicited using the standard gamble, category rating, and a treatment choice questionnaire. The groups differed substantially in the utilities assigned to colostomy. In general, patients with colostomies and physicians assigned significantly higher utilities than did patients who did not themselves have a colostomy. The clinical significance of these differences was examined in a simplified clinical decision problem that compared surgery (with colostomy) and radiotherapy (without colostomy) as primary treatment. The expected clinical value of these treatment alternatives was substantially influenced by the differences observed in utilities for colostomy. These results emphasize the importance of patient utilities in clinical decision making and the need to gain greater understanding of the factors that influence the utilities that patients assign to health states.

Ratings of the importance of quality of life variables: therapeutic implications for patients with metastatic breast cancer

Metastatic breast cancer cannot be cured with currently available therapeutic agents, and the objectives of treatment must, therefore, be directed towards other goals that include the relief of symptoms and the preservation or restoration of function. The main objective of the study reported here was to examine the relative importance of 28 items concerned with general health or with disease and treatment to a group of patients with metastatic breast cancer. All items concerned aspects of quality of life whose relevance and importance to patients with metastatic breast cancer had been shown in previous work. Patients rated items according to importance using two methods, a Q sort and a linear analogue rating. General health items, notably self-care, mobility, and physical activity, appetite, sleep, and family relationships were ranked in the upper quartile of the group of items rated. By contrast, items concerned directly with the common side-effects of chemotherapy were given lower rankings. The ratings were shown to be reproducible. These results emphasize the importance of including in clinical trials of therapy that are palliative in intent, endpoints that include those aspects of quality of life that are of greatest importance to patients.

Characterization and partial purification of human marrow cells capable of initiating long-term hematopoiesis in vitro

To develop a purification strategy for isolating the most primitive hematopoietic stem cells present in normal human marrow we have combined cell separation techniques with an assay for cells that initiate sustained hematopoiesis in vitro in the presence of irradiated human marrow adherent cells. These "feeders" were established by subculturing 2- to 6-week-old primary long-term marrow culture adherent layers at a density of 3 x 10(4) irradiated cells per square centimeter. Test "long-term culture (LTC)-initiating cells" were plated on top of the feeders and the cocultures then maintained as standard long-term marrow cultures with half-media changes and removal of half of the nonadherent cells each week. The total number of myeloid, erythroid, and multilineage clonogenic progenitors present after 5 weeks was used to provide a quantitative assessment of the number of LTC-initiating cells originally added. Using this assay, the density, light scatter, and two cell surface antigen properties of LTC-initiating cells have been defined and compared with cells capable of directly forming colonies in methylcellulose. While the majority of the clonogenic cells were found in the high forward light scatter (FLS) "blast" window, LTC-initiating cells had significantly lower FLS properties and in this respect were more similar to lymphocytes. LTC-initiating cells also expressed less HLA-DR antigen than clonogenic cells. The majority of LTC-initiating cells were found in the top 2% of the CD34 (My10) fluorescence profile, whereas clonogenic cells were found throughout the top 5% of the CD34 fluorescence profile. By combining low FLS, low orthogonal light scatter (OLS), low HLA-DR expression, and high CD34 expression, a population could be obtained that was enriched for LTC-initiating cells approximately 800-fold over unseparated marrow. This population contains only 0.06% of the marrow cells and 2% of the total clonogenic cells, but retains 50% to 60% of the LTC-initiating cells present in the original marrow. The ability to purify these two populations independently shows that the LTC and clonogenic assays identify distinct, although not necessarily nonoverlapping cell types in human marrow. Since clonogenic cells are derived from LTC-initiating cells, the LTC assay clearly detects a more primitive population. The availability of a simple approach that allows the purification of such cells by three orders of magnitude in high yield should be useful for the investigation of early events in hematopoiesis as well as for the definitive isolation of human hematopoietic stem cells with long-term in vivo repopulating potential.

Measuring Perceptions of the Exemplary Nurse

Qualitative and quantitative data identifying and weighting the perceived importance of different attributes of the "exemplary" nurse were collected from nursing respondents at different points in their professional development. Statistically significant differences in the attribute weights reported by fourth-year students and graduate nurses were observed. Because their pool was qualitatively different, quantitative comparisons with first-year students were not possible. The results indicate that these methods may be useful in examining the processes whereby the members of different groups (eg, nursing students and faculty) formulate and modify their assumptions about their own and others' professional values.

Specific binding and release of cells from beads using cleavable tetrameric antibody complexes

A two-step separation procedure is described for the positive selection of cells based on their reactivity with mouse monoclonal antibodies. In the first step cells are specifically cross-linked to hapten-modified glass beads using tetrameric monoclonal antibody complexes. In the second step bound cells are selectively eluted by reductive cleavage of the tetrameric antibody complexes. The latter are comprised of two mouse IgG1 monoclonal antibodies (one recognizing a cell surface antigen on target cells and the other a hapten coupled to the glass beads) bound together by two F(ab')2 fragments of rat anti-mouse IgG1 monoclonal antibody. The complexes provide a specific cleavable cross-link between cell and bead because the disulfide bonds between the two Fab' arms of the F(ab')2 fragments can be broken under relatively mild conditions using dithiothreitol. This specific cleavage of the cross-linker allows elution of the specifically absorbed cells without co-elution of non-specifically bound cells. This is shown in the purification of CD3+ T cells from human peripheral blood, where the removed fractions were over 90% pure and approximately 50% of the positive cells were recovered. Separation of cells labelled with limiting amounts of tetrameric antibody complexes demonstrated that this separation technique was also effective for the purification of cells expressing low amounts of antigens. This was confirmed by the purification of CD34-positive cells from human bone marrow. With this approach, colony-forming cells were enriched 15-24-fold over density separated marrow.

Measuring satisfaction with health care: a comparison of single with paired rating strategies

One of the central problems in studies of patient satisfaction with health care is the development of reliable and valid methods to determine the relative importance of different aspects of health care. Two techniques, paired comparisons and rating on a visual analogue scale, were compared in terms of their consistency with logical assumptions, test-retest reliability, and convergent validity. Thirty women with breast cancer were asked to assess brief hypothetical scenarios describing out-patient clinic visits to a tertiary cancer care centre. Each scenario incorporated three variables related to satisfaction with care: staff attitude, control over treatment decisions, and continuity of medical supervision. The paired choice method showed marginally better reliability and logical consistency than the rating method. Of the three variables assessed, continuity of medical supervision was consistently ranked highest in importance, and control over treatment decisions lowest. These preference assessment techniques appear to be suitable for use in the development of patient satisfaction indices, and for studies designed to examine variations in the priority given to different aspects of satisfaction with care.

Measurement of the clinical status of patients with breast cancer: evidence for the validity of self assessment with linear analogue scales

We have assessed the validity of a method of measurement for describing the clinical status of patients with breast cancer. One hundred and nine patients with breast cancer assigned numerical values to their own state of health using linear analogue scales. We have shown previously that this method of measurement is reliable and corresponds well with other methods of assessment. Validity was assessed in this study by examining the ability of measurements to distinguish between groups of patients who differed either in the presence of metastatic disease or in the treatments they were receiving. All patients completed the same set of 29 linear analogue scales that enquired about the severity of health related problems and symptoms. In general, patients with metastatic disease were clearly distinguished from patients without metastases by their scores on items related to physical function. Patients receiving chemotherapy were distinguished from those not receiving chemotherapy by their scores on treatment related toxicities. Measures of psychological and social health were similar in patients receiving chemotherapy regardless of disease status. These results provide further support for the validity of measurement of clinical status with linear analogue scales scored by patients.

Why are (or are not) patients given the option to enter clinical trials?

Much attention has been paid to the use of ethical principles to guide the conduct of clinical trials. Less has been done to clarify and assess the "weights" assigned by clinicians (and others) to the values that come into conflict when patients are offered entry into trials. Quantitative techniques of value assessment were used to measure the relative importance of variables frequently identified as barriers to the entry of patients into clinical trials. Responses were obtained from 52 oncologists, 26 clinical trials and senior nurses, and 23 family physicians. The group of oncologists identified the scientific design of the trial as the most important factor. In contrast, the groups of nurses and family physicians gave higher weight to effects of the trial on the doctor-patient relationship. The results illustrate ways in which methods of value assessment may be used to clarify and rank values.

Weight gain during adjuvant chemotherapy for breast cancer

Weight gain during adjuvant chemotherapy has been reported by several authors. Because increased body weight at diagnosis is associated with an increased risk of disease recurrence, we have assessed the prevalence of weight gain in a series of patients receiving adjuvant treatment, as well as the association of weight gain with type of treatment and risk of recurrence. We first assembled an inception cohort of 237 patients who had all undergone pretreatment evaluation and treatment at one institution, and had already been followed for at least 12 months. Body weight at the start and completion of treatment was recorded, as was type of treatment and status at last followup. Ninety-six percent of patients gained weight during treatment and none lost weight (mean increase 4.3 kg). Weight gain was strongly associated with treatment, and was least in patients receiving single agent chemotherapy, greatest in patients treated with ovarian ablation and prednisone, and intermediate in those receiving combination chemotherapy. There was no association between weight gain and disease recurrence.

Do patients and physicians agree on the assessment of voice quality in laryngeal cancer?

Information is available regarding tumor control rate and survival for patients with cancer of the larynx. Less well known are the effects of treatment upon the patient's quality of voice and way of life because there is at present no suitable method for the routine clinical assessment of these effects. This paper reports some results of the evaluation of one assessment technique using linear analogue scales, and it examines the agreement between patients' and physicians' assessment of severity of voice related function and sound. Each of 20 patients taped a voice recording and subsequently rated his overall functional ability and the sound of his voice. Twenty physicians rated the sound of the 20 patients' voices from the recording and judged functional ability from a written description. Agreement between the scores of patients and physicians indicated that despite being strongly correlated, they were often not the same. Implications of this technique are discussed.

Describing health states. Methodologic issues in obtaining values for health states

In health status index construction quantitative values for different states of health are frequently obtained by presenting written descriptions to raters whose values are elicited using one or more methods. In this study the authors examined the influence of several aspects of this measurement process upon the quantitative results obtained. They prepared a set of written descriptions of health states, each state being described in both a standard point-form and a narrative format. The narrative format was written in the first person singular, and listed all symptoms or problems associated with the state, whereas the point-form description included only the most severe symptom or problem. Values for these states were elicited from a group of 64 patients using two commonly employed methods, the standard gamble of Von Neumann and Morgenstern and category rating. The results indicate that the type of scenario presented to the rater and the sequence in which the methods of assessment were used had a major influence on the results. This work indicates that there is a need to examine systematically the process of obtaining quantitative values before reliance can be placed upon the results.

The assessment of values in laryngeal cancer: reliability of measurement methods

Although quantitative estimates of patients' attitudes toward the relative importance of different aspects of health are of great potential usefulness in medical decision making, there is little information about the stability of such values over time, particularly in patients whose clinical state is changing. To examine these questions, we selected a group of patients with laryngeal cancer undergoing treatment with radiotherapy. In this group of patients clinical problems are relatively circumscribed and related to the voice, and a temporary deterioration in voice-related symptoms and abilities is expected during treatment. Thirty patients were interviewed at the start and completion of a month's course of treatment. At each interview patients rated the quality of their own voices using a number of visual analogue scales and also provided both holistic and decomposed quantitative values for the importance of different aspects of voice function and sound. Although the analogue scales demonstrated the anticipated deterioration in the quality of the patients' voices, these changes in clinical state were not accompanied by any changes in the values the patients assigned to each aspect of voice sound and function. These results indicate that at least in the short term the values expressed by patients appear to be stable and uninfluenced by changes in their own clinical state. Longer term studies involving more systemic illnesses should now be carried out.

Linear analogue self-assessment of voice quality in laryngeal cancer

This study evaluated the reliability and sensitivity of laryngeal cancer patients' linear analogue self-assessments (LASA) of voice quality. Thirty patients completed LASA scales for a number of voice-related symptoms and abilities several times during a standard treatment programme. The study design allowed evaluation of the scales' reliability, both early and late in treatment, and sensitivity to the changes expected during irradiation. Another 29 post-treatment patients completed the same scales in interviews separated by several weeks. Results indicate that LASA scores were generally reliable, sensitive to clinical change, yet stable when clinical status is unaltered. Though further demonstrations of the validity of these scales are required, their possible use as outcome measures in future clinical trials comparing treatments for laryngeal cancer is feasible.

Measurement of values for states of health with linear analog scales

Medical decisions may be greatly influenced by the values that patients place on different states of health. Previous attempts to obtain quantitative estimates of such values have assumed the numerical values assigned to different levels of health will remain constant regardless of the context in which the measurement is made. To examine this assumption, 64 ambulatory patients ranked five scenarios describing different states of health in order of preference. One of the scenarios was ranked as worse than death by 22 percent of raters, and two scenarios were ranked as worse than death by 31 percent of raters. The states were then rated using linear analog scales, first with the anchors or endpoints of perfect health and death, then with the anchor of perfect health replaced by each of the other health states, in descending order of preference, and finally with the anchor of death replaced by each of the other health states, in ascending order of preference. The numerical values assigned to scenarios were substantially and systematically influenced by the anchors on the scale. Relative to the values assigned to health states when anchors of perfect health and death were employed, the same states were assigned systematically higher values when the anchor of death was replaced by other health states, and systematically lower values when the anchor of perfect health was replaced. These findings persisted when states considered worse than death were excluded from the rating process. These results indicate that the quantitative values assigned health states are strongly influenced by the context in which the measurement is made, and that health cannot be regarded as a continuum with death as its lower boundary.

The measurement of patients' values in medicine

The standard gamble, derived from decision theory, is considered a criterion method for obtaining patients' values for different health states. In this method, a rater's value for a health state is obtained by determining, in a hypothetical setting, his readiness to remain in that state or take a risky choice with different outcomes of known value. According to the expected utility criterion, a rater's utility or value for a particular state should not be influenced by changes in the gamble outcomes. The standard gamble was used to obtain 64 patients' judgments of a set of health states, first with the outcomes of perfect health or death, and subsequently with other health states as outcomes. The changes in gamble outcomes significantly influenced reported values for health states, indicating that the standard gamble is internally inconsistent. This observation poses a major limitation to its use as a value measurement method in medicine.

Attitudes toward quality of survival. The concept of "maximal endurable time"

The purpose of this study was to examine attitudes toward the duration of survival in different health states. Health professionals were asked to consider hypothetical situations in which a specified period of time would be spent in a defined health state. Preferences for these different situations were assessed using two methods--a Preference Questionnaire and a Certainty Equivalence method. The results obtained indicated that attitudes toward duration of survival depended strongly on the amount of time to be spent in a hypothetical health state, and on the quality of the state. As the duration of survival increased, or the state under consideration became more dysfunctional, a higher proportion of raters expressed a preference for immediate death over further survival in the dysfunctional state. These results contradict the view that time preference curves always increase monotonically, independent of the quality of survival. Instead, subjects appeared to identify a variable, the "maximal endurable time" in a given state. When this time was exceeded, attitudes toward additional increments of survival changed dramatically.

Prospective evaluation of physical examination of the breast

The reliability of physical examination of the breast was evaluated by determining the extent of agreement among four experienced breast surgeons who examined the same 100 patients. The consequences of disagreements among surgeons were assessed by determining the diagnostic accuracy of each examiner. Despite differences in the frequency with which each surgeon found abnormalities or masses, or recommended mammography or biopsy, the diagnostic accuracy of the surgeons was very similar, and most disagreements concerned the findings in patients who did not have breast cancer. Breast examination carried out by more than one surgeon may reduce the frequency with which biopsy is performed in patients who do not have breast cancer.