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Biomedical subjects

K McPherson

Publications and source records attributed to K McPherson.

At least 199 records · Page 11Linked to original sources
PubMed1984

Will payment based on diagnosis-related groups control hospital costs?

Previous studies have shown that the admission rates for a few surgical procedures, such as hysterectomy, vary extensively among hospital market areas, apparently because of differences in physicians' practice styles. To see whether such variations occur for most causes of admission, we classified all nonobstetrical medical and surgical hospitalizations in Maine for the years 1980 through 1982 into diagnosis-related groups (DRGs) and measured the variations in admission rates among 30 hospital market areas. Hysterectomy rates varied 3.5-fold, but 90 per cent of medical and surgical admissions fell into DRGs for which admission rates were even more variable, suggesting that professional discretion plays an important part in determining hospitalization for most DRGs. Losses in hospital revenues resulting from the DRG payment system could be offset if physicians modified their admission policies to produce more profit, well within the current limits of medical appropriateness. If this occurred, the net effect of a DRG program would be to exacerbate hospital cost inflation. We conclude that, to be successful, cost-containment programs based on fixed, per-admission hospital prices will need to ensure effective control of hospitalization rates.

Cost Control↗
PubMed1984

A randomized controlled trial of cervical cerclage in women at high risk of spontaneous preterm delivery.

The effect of cervical suture on pregnancy outcome was studied in 194 women with a high risk (approximately 30%) of having a late abortion or a preterm delivery. The women were randomly allocated either to have a cervical suture inserted (n = 96) or to be managed without a suture (n = 98). There was no evidence that cervical cerclage either prolonged gestation or improved survival. Patients allocated to receive cerclage spent significantly longer in hospital, even when the period of admission for insertion was excluded. The patients in the cerclage group were more likely to receive tocolytic drugs, and more of them experienced puerperal pyrexia, although these differences between the groups were not statistically significant.

Adolescent↗
PubMed1984

Long-term follow-up of intraocular lens implants: the first 127 compared with the latest 100 of the same style in a span of 9 years.

The long-term follow up of the first 127 patients (127 eyes) treated by one surgeon with cataract extraction and Federov I lens implantation is reported. The proportion of patients achieving visual acuity of 6/12 or better had decreased since the one year follow-up. Corneal oedema was the most serious long-term complication. This group of patients is compared with the latest 100 patients (100 eyes) operated on by the same surgeon using the same type of implant. There was a reduction of some operative complications, and improvement in surgical techniques had resulted in a lower sample endothelial cell loss at one month.

Aged↗
PubMed1984

Maternal age and breast cancer risk.

Maternal age at time of birth was investigated as a risk factor for breast cancer in a study of 1,176 matched case-control pairs. There was no pattern of increasing adjusted relative risk of breast cancer with increasing maternal age, nor was the mean maternal age of cases older than that of controls. Similar negative results were found among the subset of subjects up to 35 years old, a group previously found to show marked maternal age effects. Thus previous reports of an association between breast cancer and advanced maternal age may have been due to chance, extraneous factors, or a misleading reliance on unadjusted mean maternal ages, rather than on relative risks.

Adult↗
PubMed1983

The use of intrapartum fetal blood lactate measurements for the early diagnosis of fetal distress.

Lactate concentrations were measured during labor and at delivery in blood samples from the fetal presenting part and from the umbilical cord with the use of a rapid electrochemical technique. The value of these measurements to discriminate between normal and distressed fetuses was compared to that of pH, base excess, PCO2 and PO2 measurements in the same blood samples. The fetuses were divided into three groups, normal, prepathologic, and pathologic, according to the presence and severity of fetal distress as evaluated by Apgar score, intrapartum cardiotocography, meconium staining of the amniotic fluid, and cord arterial pH at birth. Lactate and pH provided the best parameters to distinguish between groups, with lactate having the most discriminating power at least in early labor and midlabor. The prospective value of discriminant functions derived from lactate and pH data was good when the fetuses were allocated into the normal group but poor when an attempt was made to allocate the fetuses into prepathologic and pathologic groups, with a high false negative rate. However, the discriminating ability was improved when prepathologic and pathologic fetuses were included into one single abnormal group. These results confirm the potential use of rapid fetal blood lactate measurements for the early diagnosis of intrapartum fetal distress.

Acid-Base Equilibrium↗
PubMed1983

Neoplasia of the cervix uteri and contraception: a possible adverse effect of the pill.

The incidence of biopsy-proven cervical neoplasia during a 10-year follow-up was determined in 6838 parous women who entered the Oxford-Family Planning Association contraceptive study while using oral contraceptives and 3154 parous women who entered the study while using an intrauterine device (IUD). Risk factors for cervical neoplasia, continuation of attendance at family planning clinics, and frequency of examination by cervical cytology were similar in the two groups. All 13 cases of invasive cancer occurred in women in the oral contraceptive group; 9 had more than 6 years' use of the pill. Both carcinoma-in-situ and dysplasia also occurred more frequently in the oral contraceptive group than in the IUD group, and when the two conditions were considered together there was a trend in incidence with duration of oral contraceptive use. The incidence for all three forms of neoplasia combined rose from 0.9 per 1000 woman-years in those with up to 2 years' pill use to 2.2 per 1000 woman-years in those with more than 8 years' pill use. Amongst IUD users, there was no such trend in incidence with duration of use: the rate fluctuated around 1.0 per 1000 woman-years. The great majority of cases of invasive cancer were detected by means of cervical smears and were treated while the disease was still curable. Long-term users of oral contraceptives should have regular cervical cytological examination.

Adult↗
PubMed1983

Prevention of deterioration of renal and sensory-nerve function by more intensive management of insulin-dependent diabetic patients. A two-year randomised prospective study.

74 insulin-dependent diabetic patients with background retinopathy were randomised to continue with usual diabetic care (group U) or to a more intensive programme (group A) using ultralente insulin as basal cover and soluble insulin at mealtimes. Group A attended the clinic more frequently, received closer dietary supervision, and were taught home blood glucose monitoring. Group A had a significantly lower mean glycosylated haemoglobin level during the study, although the mean level also fell in group U towards the end of year 2. Renal and sensory-nerve function were significantly better preserved in group A than in group U. Significant improvements were also seen in low-density-lipoprotein-cholesterol and whole-blood low-shear viscosity. The rate of progression of retinopathy was similar in both groups. It appears that a modest improvement in diabetic control, obtainable in most clinics, has been associated with a reduction in the progression of diabetic tissue damage.

Blood Glucose↗
PubMed1983

Oral contraceptives and breast cancer: final report of an epidemiological study.

During 1968-1980, 1176 women aged 16-50 years with newly diagnosed breast cancer and a like number of matched controls were interviewed at 9 teaching hospitals in London and Oxford and asked about their use of oral contraceptives. The results were reassuring. A few statistically significant differences in oral contraceptive use were found between the breast cancer and control groups, but the data were subdivided in many ways so that some "significant" differences would have been expected through the play of chance alone. Certainly no patterns of risk emerged which would suggest that any of the associations were causal. It must be stressed, however, that the data are still sparse in some important subcategories--for example, only small numbers of both cases and controls had prolonged oral contraceptive use before their first term pregnancy. For this reason, it is important that information on the possible relationship between pill use and breast cancer should continue to be collected. Women who had never used oral contraceptives presented with appreciably more advanced tumours than those who had been using oral contraceptives during the year before detection of cancer, while past users were in an intermediate position. These differences in staging were reflected in the pattern of survival. Possible explanations for these observations include "surveillance bias" among oral contraceptive users leading to earlier diagnosis and a beneficial biological effect of oral contraceptives on tumour growth and spread. Women with breast cancer reported never having used any method of contraception and heavy cigarette smoking (greater than or equal to 15 per day) significantly less often than controls. We could find no obvious explanation for the former observation, but suspect that the latter reflects the unrepresentative smoking habits of our hospital controls rather than a protective effect of smoking against breast cancer.

Adolescent↗
PubMed1983

Tubal sterilization: findings in a large prospective study.

Of the 17032 women taking part in a large prospective study of the beneficial and harmful effects of different contraceptive methods, 2243 (13%) had undergone tubal sterilization by the end of 1981 while another 3551 (21%) had husbands who had undergone vasectomy. The most commonly used female sterilization procedure was laparoscopic tubal diathermy. About 19% of all operations were carried out at the time of a delivery or during the subsequent 4 weeks. In total, 16 accidental pregnancies have occurred in the sterilized women, the failure rate during the 12 months after surgery being 0.37 per 100 woman-years and the rate during the subsequent months being 0.10 per 100 woman-years. Of the 16 accidental pregnancies, seven were ectopic. In an analysis comparing women who had undergone tubal sterilization with those whose husbands had undergone vasectomy, there was little evidence of any excess occurrence of gynaecological or psychiatric disorders in the former group.

Adult↗