Explaining breast cancer mortality in England: the effect of socioeconomic factors and health care services.

England has the worst mortality rate for breast cancer in the developed world. Using area-level data for 145 health districts in England, this study seeks to explain variations in breast cancer mortality among women aged 50-64 years in the period before the National Breast Screening Programme became operational. It is found that socioeconomic and behavioural factors had a larger effect on mortality than did health care inputs. This might be explained both by inadequacies in the data, and by the fact that, in the absence of screening, cancers tend to be detected at a later stage, by which time the chances of a successful outcome are reduced. It is suggested that the impact of health care services in reducing mortality will increase in the future as screening becomes widespread and results in earlier detection and treatment. The prioritization of screening is central to achieving the reductions in mortality from breast cancer specified in the Health of the Nation targets.

Role of screening in reducing invasive cervical cancer registrations in England.

OBJECTIVE: To estimate the effect of screening on invasive cervical cancer registrations in England. SETTING: The Health of the Nation target for cervical cancer seeks to reduce the incidence of invasive cases (ICD 180) by at least 20% between 1986 and 2000. METHOD: The available area-level statistics on invasive cervical cancer registrations, screening activity, and socioeconomic and behavioural characteristics for 145 district health authorities in England over the period 1985-91 were collected. A multiple regression analysis sought to explain variations in incidence rates by relating screening and socioeconomic and behavioural variables to registration rates. RESULTS: Districts with higher unemployment levels and higher numbers of pregnancies in young women had higher registration rates for invasive cervical cancer. The cervical smear rate for women aged 35-64 in a district was positively related to registrations, whereas the relation was negative for the 20-34 age group. CONCLUSIONS: The higher registration rates for invasive cervical cancer in districts with higher cervical smear rates for women aged 35-64 may reflect historically lower screening cover. The negative relation between the cervical smear rate and invasive cervical cancer registrations in women aged 20-34 is accompanied by high registration rates for preinvasive (CIN III) cervical cancer (ICD 233.1). For the advantages of the Pap test to be fully realised, and for invasive cervical cancer registrations to fall in line with the Health of the Nation targets, a comprehensive screening programme, with a high take up rate is required. The various changes to the screening programme introduced since 1988 should help to achieve this. Public health policy should focus on educating the population about the risk factors for cervical cancer and the significance of screening.

Use of the force-velocity test to determine the optimal braking force for a sprint exercise on a friction-loaded cycle ergometer.

A group of 15 untrained male subjects pedalled on a friction-loaded cycle ergometer as fast as possible for 5-7 s to reach the maximal velocity (vmax) against different braking forces (FB). Power was averaged during a complete crank rotation by adding the power dissipated against FB to the power necessary to accelerate the flywheel. For each sprint, determinations were made of peak power output (Wpeak), power output attained at vmax (Wvmax) calculated as the product of vmax and FB and the work performed to reach vmax expressed in mean power output (Wvmax). The relationships between these parameters and FB were examined. A biopsy taken from the vastus lateralis muscle and tomodensitometric radiographs of both thighs were taken at rest to identify muscle metabolic and morphometric properties. The Wpeak value was similar for all FB. Therefore, the average of values was defined as corrected maximal power (Wmax). This value was 11% higher than the maximal power output uncorrected for the acceleration. Whereas the Wmax determination did not require high loads, the highest Wvmax value (Wmax) was produced when loading was heavy, as evidenced by the Wvmax-FB parabolic relationship. For each subject, the braking force (FB,Wmax) giving Wmax was defined as optimal. The FB,Wmax, equal to 0.844 (SD 0.108) N.kg-1 bodymass, was related to thigh muscle area (r = 0.78, P < 0.05). The maximal velocity (vm,Wmax) reached against this force seemed to be related more to intrinsic fibre properties (% fast twitch b fibre area and adenylate kinase activity). Thus, from the Wmax determination, it is suggested that it should be possible to predict the conditions for optimal exercise on a cycle ergometer.

Effect of 40 weeks of endurance training on the anaerobic threshold.

The effect of a 40-week training program on the anaerobic threshold (AT) was studied in five subjects (35 +/- 5 yrs). The training program consisted of a bicycle ergometer exercise 1 h per day 3 days a week at a work load corresponding to 80%-85% of VO2 max. Before training (S0) and at the 10th, 20th, 30th, 40th weeks (S10, S20, S30, S40) of the training program, ventilatory AT (AT vent), lactate AT (AT lact), and 4 mmol AT were estimated using a graded exercise test. In the same period, another test (1) to determine VO2 max, maximal work load (MWL), and net efficiency (2) and a 1-h endurance exercise requiring 85%-90% of VO2 max were performed. After training, AT increased significantly by 10%, 11%, and 18% in AT vent, AT lact, and AT 4 mmol, respectively. MWL and net efficiency increased by 22% and 14% respectively, and there was no significant increase in VO2 max. The AT increase at S20 was delayed as compared to the change in MWL (S10). It is hypothesized that an AT increase provides good evidence for modifications of the muscular oxidative capacities during an endurance training program. A part of this paper is devoted to (1) the study of the reproducibility of AT estimation, (2) a comparison to other methods for determining the definition of AT, and (3) the correlations between the three methods utilized for AT estimation.