Survival ratio plots with permutation envelopes in survival data problems.

A new method is proposed, based on a simple ratio plot, which is useful for identifying time intervals or regions in which survival prospects differ between two distinct populations or treatments. In order to investigate whether any observed difference or trend is due to sampling variation or is due to a possible real effect, resampling techniques are used to generate permutation envelopes as reference bands. The method is applicable to the comparison of survival in two populations for both independent and paired survival problems and also to the assessment of the symmetry of a bivariate survival function.

The effect of towing a range of relative resistances on sprint performance.

The aim of this study was to compare sprint performance over 10 and 20 m when participants ran while towing resistances, weighing between 0 and 30% of body mass. The sample of 33 participants consisted of male rugby and soccer players (age 21.1 +/- 1.8 years, body mass 83.6 +/- 13.1 kg, height 1.82 +/- 0.1 m; mean +/- s). Each participant performed two sets of seven sprints over 20 m using a Latin rectangular design. The times were recorded at 10 and 20 m using electronic speed gates. The sprints of 13 players were video-recorded to allow calculation of stride length and frequency. For both sprints, a quadratic relationship was observed between sprint time and resistance as sprint time increased from 2.94 s to 3.80 s from 0 to 30% resistance. This relationship was statistically significant but considered not to be meaningful for performance because, over the range of resistances used in this study, the quadratic model was never more than 1% (in terms of sprint time) from the linear model. As resistance increased, the stride length shortened, with mean values of 1.63 +/- 0.13 m at 0% body mass and 1.33 +/- 0.13 m at 30% of body mass. There was no significant change in stride frequency with increasing resistance. The results show that in general there is an increase in sprint time with an increase in resistance. No particular resistance in the range tested (0 - 30%) can be recommended for practice.

Is it possible to predict the blood volume of a sick preterm infant?

OBJECTIVE: To investigate the relation between the measured intravascular blood volume (BV) and current methods of indirectly assessing BV status in sick preterm infants on the first day of life. METHODS: Thirty eight preterm infants of gestation 24-32 weeks (median 30) and weight 480-2060 g (median 1220) were studied. Red cell volume was measured by the fetal haemoglobin dilution method in six infants and by the biotin labelled autologous red cell dilution method in the remaining 32. Total BV was calculated by dividing red cell volume by packed cell volume. Indirect assessments of BV status using heart rate (HR), core-peripheral temperature difference, mean arterial pressure, base excess, and packed cell volume were recorded. RESULTS: The mean (SD) initial measured BV was 71 (12) ml/kg (range 53-105). The mean HR was 148 beats/min (range 130-180), which correlated positively (r = 0.39, p = 0.02) with BV (higher HR was associated with higher BV). The mean base excess was -3.19 mmol/l (range -18 to +6.2). The negative base excess correlated significantly positively (r = 0.41, p < 0.01) with BV (more acidotic babies tended to have higher BV). There was no significant correlation between core-peripheral temperature difference, mean arterial pressure, or packed cell volume and BV. Regression analysis showed that base excess and HR were significantly related to BV; base excess alone can predict variability in BV only to 17%, and base excess with HR can predict variability in BV to 29%. CONCLUSION: The conventional clinical and laboratory indices are poor predictors of measured blood volume.

The effects of a 12-week group exercise programme on physiological and psychological variables and function in overweight women.

OBJECTIVES: The aim of this study was to investigate the effect of a 12-week functional exercise programme on overweight women. METHODS: Twenty-six subjects (n=13 exercisers, n=13 controls) aged (mean+/-SD) 63 (+/-4) years completed the study. The exercise sessions were carried out twice each week for 12 weeks. The variables measured were body mass, body mass index, skin-fold thickness, resting blood pressure, total blood cholesterol, chair rise, timed 'up and go' test, 20-m walk,lifting a 1- and a 2-kg bag on to a shelf, stair walking, 'sit and reach' flexibility test, Life Satisfaction Index and Physical Self-perception Profile for Older Adults. The exercise sessions consisted of 40-min sessions during which the subjects performed aerobic and strength exercises. RESULTS: Paired analyses showed that body mass, body mass index, blood pressure (systolic and diastolic values), 'up and go' time, time to complete a 20-m walk, time to lift a 1- and a 2-kg bag with both the right and left arms onto a shelf, and stair climbing-total time and ascent time-decreased significantly in the exercise group. Also, the exercise group improved their Life Satisfaction Index score significantly compared with the control group. CONCLUSIONS: The results indicate that a functional exercise programme has the potential to improve performance in a number of physiological variables and functional activities in overweight women. The exercise programme enhanced life satisfaction.

Assessing restorative dental materials: 2. Questions for a dental sales representative.

Many methodologies are used during the testing of dental materials, although different tests are suitable for different materials and clinical situations. This paper discusses factors relevant to the choice of a dental material, and suggests questions that a practitioner would find helpful to ask a dental sales representative, such as ease of use, effect on the environment and the relevance of fluoride release.

Assessing restorative dental materials: I. Test methods and assessment of results.

Many methodologies are used during the testing of dental materials. Among these are compressive, tensile and flexural strengths, and fracture toughness. However, different tests are relevant to different materials and clinical situations. This paper describes different test methodologies and discusses the substantiation of research claims in publications and advertising.

A comparison of the anthropometric, strength, endurance and flexibility characteristics of female elite and recreational climbers and non-climbers.

There is limited information on the anthropometry, strength, endurance and flexibility of female rock climbers. The aim of this study was to compare these characteristics in three groups of females: Group 1 comprised 10 elite climbers aged 31.3 +/- 5.0 years (mean +/- s) who had led to a standard of 'hard very severe'; Group 2 consisted of 10 recreational climbers aged 24.1 +/- 4.0 years who had led to a standard of 'severe'; and Group 3 comprised 10 physically active individuals aged 28.5 +/- 5.0 years who had not previously rock-climbed. The tests included finger strength (grip strength, finger strength measured on climbing-specific apparatus), flexibility, bent arm hang and pull-ups. Regression procedures (analysis of covariance) were used to examine the influence of body mass, leg length, height and age. For finger strength, the elite climbers recorded significantly higher values (P < 0.05) than the recreational climbers and non-climbers (four fingers, right hand: elite 321 +/- 18 N, recreational 251 +/- 14 N, non-climbers 256 +/- 15 N; four fingers, left hand: elite 307 +/- 14 N, recreational 248 +/- 12 N, non-climbers 243 +/- 11 N). For grip strength of the right hand, the elite climbers recorded significantly higher values than the recreational climbers only (elite 338 +/- 12 N, recreational 289 +/- 10 N, non-climbers 307 +/- 11 N). The results suggest that elite climbers have greater finger strength than recreational climbers and non-climbers.

A comparison of mobility assessments in a geriatric day hospital.

OBJECTIVE: To assess the sensitivity of the Elderly Mobility Scale (EMS) to detect improvements in mobility after physiotherapy in comparison with the Barthel Index (BI) and Functional Ambulation Category (FAC) in routine clinical day hospital practice. SUBJECTS: Eighty-three patients who completed a course of physiotherapy were studied. METHODS: Each was assessed by an independent physiotherapist before and after a programme of physiotherapy, using the EMS, BI and FAC. RESULTS: The mean age was 79 years (SD 7.7). Fifty-three out of 83 (64%) patients were female and 92% were community dwelling. The median number of physiotherapy sessions undergone by each patient was 9 (range 3-51). All three scales detected an improvement in mobility with physiotherapy (p < 0.001). However, using the EMS, 68 out of 82 (83%) patients had a detectable improvement in mobility compared with only 34 out of 80 (42%) using the BI and 28 out of 81 (35%) using the FAC. Using a matched-pairs comparison, the EMS was significantly more likely to detect an improvement in mobility following physiotherapy within the study group than the BI (p < 0.001) or the FAC (p < 0.001). CONCLUSION: Although all three scales detected improvements in mobility, the EMS detected mobility improvements in a significantly greater number of patients.

Randomised controlled trial of homoeopathy versus placebo in perennial allergic rhinitis with overview of four trial series.

OBJECTIVE: To test the hypothesis that homoeopathy is a placebo by examining its effect in patients with allergic rhinitis and so contest the evidence from three previous trials in this series. DESIGN: Randomised, double blind, placebo controlled, parallel group, multicentre study. SETTING: Four general practices and a hospital ear, nose, and throat outpatient department. PARTICIPANTS: 51 patients with perennial allergic rhinitis. INTERVENTION: Random assignment to an oral 30c homoeopathic preparation of principal inhalant allergen or to placebo. MAIN OUTCOME MEASURES: Changes from baseline in nasal inspiratory peak flow and symptom visual analogue scale score over third and fourth weeks after randomisation. RESULTS: Fifty patients completed the study. The homoeopathy group had a significant objective improvement in nasal airflow compared with the placebo group (mean difference 19.8 l/min, 95% confidence interval 10.4 to 29.1, P=0.0001). Both groups reported improvement in symptoms, with patients taking homoeopathy reporting more improvement in all but one of the centres, which had more patients with aggravations. On average no significant difference between the groups was seen on visual analogue scale scores. Initial aggravations of rhinitis symptoms were more common with homoeopathy than placebo (7 (30%) v 2 (7%), P=0.04). Addition of these results to those of three previous trials (n=253) showed a mean symptom reduction on visual analogue scores of 28% (10.9 mm) for homoeopathy compared with 3% (1.1 mm) for placebo (95% confidence interval 4.2 to 15.4, P=0.0007). CONCLUSION: The objective results reinforce earlier evidence that homoeopathic dilutions differ from placebo.

Nutritional intake of an undernourished infant population receiving an energy and micronutrient supplement in Indonesia.

OBJECTIVES: This paper reports the dietary intake (home, day care centers, supplement and breast milk) of the children in the clinical trial in Pangalengan. DESIGN: Two cohorts of children were randomly assigned to three treatments: E = 1171 kJ + 12 mg iron; M = 209 kJ + 12 mg iron; S = 104 kJ. Supplementation was given for 12 months. SETTING: The sites were six tea plantations in Pangalengan, West Java. SUBJECTS: A 12-month-old (n = 53) and an 18-month-old (n = 83) cohort were recruited from day-care-centers. Twenty children who received S belong to the 12- and 18-month-old cohorts. Inclusion criteria were: no chronic disease; length-for-age < or = -1 standard deviation (s.d.) and weight-for-length between -1 and -2 s.d. of the median of the reference of the World Health Organization. METHODS: E = 1171 kJ + 12 mg iron; M = 209 kJ + 12 mg iron; S = 104 kJ. Supplementation was given for 12 months. Evaluations of intake were made at baseline and every 2 months thereafter. RESULTS: For the 12-month-old cohort the mean increase in daily energy intake approximately 2931 kJ for E, approximately 1675 kJ for M, and approximately 837 kJ increase over the 6 months for the S group. For the 18-month-old cohort the changes were approximately 2512 kJ for E approximately 1675 for the M group and approximately 1047 for the S group.

Effects of an energy and micronutrient supplement on growth and activity, correcting for non-supplemental sources of energy input in undernourished children in Indonesia.

OBJECTIVES: This paper investigates simultaneously the growth and activity of children that received an early energy and micronutrient supplement, adjusting for all non-supplemental energy intakes. Any additional change in growth and activity after this adjustment was then compared across supplements at three points felt to be representative of the study. DESIGN: Two cohorts of children were randomly assigned to three treatments: E = 1171 kJ + 12 mg iron; M = 209 kJ + 12 mg iron; S = 104 kJ. Supplementation was given for 12 months. SETTING: The sites were six tea plantations in Pangalengan, West Java. SUBJECTS: A 12-month-old (n = 53) and an 18-month-old (n = 83) cohort were recruited from day-care-centers. Twenty children that received S belonged to the 12- and 18-month-old cohorts. Inclusion criteria were: no chronic disease; length-for-age < or = -1 standard deviation (s.d.) and weight-for-length between -1 and -2 s.d. of the median of the reference of the World Health Organization. METHODS: Length was measured with a portable measuring board; a Detecto scale with an accuracy of 0.1 kg was used for the measurement of body weight. Arm and head circumferences were measured using similar fiberglass tapes. Motor activity was assessed through continuous 4 h observations at home and at day care centers. Anthropometry and activity were measured every two months over 12 months. RESULTS: After correcting for non-supplemental sources of energy intake, the effects of the supplement on weight and activity were observed at 2 months; effects on length and activity were observed at 6 months; and effects on weight alone were observed at 12 months.

Effects of an energy and micronutrient supplement on anthropometry in undernourished children in Indonesia.

OBJECTIVES: This paper reports the effects of early supplementary feeding on body weight, length, head circumference and arm circumference among the children in the Pangalengan study. DESIGN: Two cohorts of children were randomly assigned to three treatments: E = 1171 kJ + 12 mg iron; M = 209 kJ + 12 mg iron; S = 104 kJ. Supplementation was given for 12 months. SETTING: The sites were six tea plantations in Pangalengan, West Java. SUBJECTS: A 12-month-old (n = 53) and an 18-month-old (n = 83) cohort were recruited from day-care centers. Twenty children that received S belonged to the 12- and 18-month cohorts. Inclusion criteria were: no chronic disease; length-for-age < or = -1 standard deviation (s.d.) and weight-for-length between -1 and -2 s.d. of the median of the reference of the World Health Organization. METHODS: Length was measured with a portable measuring board; a Detecto scale with an accuracy of 0.1 kg was used for the measurement of body weight. Arm and head circumferences were measured using similar fiberglass tapes. RESULTS: Body weight showed effects on both cohorts at 2, 8 and 12 months; head circumference showed effects at 4 months in the 12-month-old cohort and at 10 months among the females of the 18-month-old cohort; and arm circumference showed effects across cohorts at 2, 8 and 12 months. In general the benefits are clearer for females and for the 12-month-old cohort.

Efficacy of the cyclodextrin liquid preparation of itraconazole in treatment of denture stomatitis: comparison with itraconazole capsules.

This study investigated the efficacy of a cyclodextrin solution of itraconazole in the treatment of Candida-associated denture stomatitis. It was found that the liquid and capsule preparations of itraconazole were equally effective adjuncts in the treatment of this condition. However, the side effect profile indicates that capsules are the preferred formulation.

False positive ECG reports of anterior myocardial infarction in women.

The prevalence of electrocardiographic poor R-wave progression was estimated by reviewing all electrocardiograms recorded in Glasgow Royal Infirmary over a 2-week period. It was found to be higher in women (19% vs. 11%) than in men. To investigate one possible reason, the effect of chest electrode positioning in women was thereafter examined. Eighty four women were recruited to a study in which chest electrodes were placed strictly in adherence with recommendations of using the 4th and 5th intercostal spaces as references and also using the more widely adopted technique of placing electrodes V3 to V6 under the left breast. R wave amplitudes were compared in V3 to V6 from both sets of recordings. It was found that measurements recorded on the breast by electrode V3 have a significantly smaller R wave magnitude compared to corresponding measurements below the breast, the mean difference being 34 (95% confidence interval [CI] of 7 to 60) microvolts. For V5 and V6, the reverse is true with measurements taken on the breast being larger, on average, than those taken below the breast by 119 (95% CI of 87 to 152) and 134 (95% CI of 108 to 160) microvolts respectively. For V4, there was no significant difference. Seventeen women with poor R wave progression suggestive of old anterior myocardial infarction had clinical data examined from which it was determined that 11 had a history suggestive of myocardial infarction, ie, the positive predictive value was 65% (95% CI of 42% to 87%). It was concluded that positioning of electrodes beneath rather than on top of the breast was not responsible for the increased prevalence of poor R wave progression in women and that the criterion of isolated poor R wave progression was too nonspecific to be of clinical value.

Traumatic wound rupture after penetrating keratoplasty in Africa.

AIM: To investigate risk factors, visual outcome, and graft survival for traumatic wound rupture after penetrating keratoplasty. METHODS: A retrospective analysis of 336 patients who underwent penetrating keratoplasty from 1988 to 1995. RESULTS: 19 patients (5.7%) suffered traumatic postoperative wound rupture requiring surgical repair. They were younger (mean age 16.6 years, 95% CI 13.2-20.6) and more frequently keratoconic (p = 0.01) than other patients (mean age 28.9 years, 95% CI 26.-31.0). Mean postoperative follow up was 37.7 (SD 22.9) months and 24.5 (18.9) months for the rupture and non-rupture patients. Mean interval between keratoplasty and rupture was 18 (21) weeks. The lens was damaged and removed in 37% of ruptured eyes. For keratoconics, the probability of graft survival at 5 years was lower (p = 0.03) in the ruptured eyes (75%) than in the non-ruptured eyes (90%). Endothelial failure was a more common (p <0.05) cause of graft opacification in ruptured grafts than in intact grafts. Of the ruptured eyes, 53% achieved a final corrected acuity of at least 6/18 and 63% achieved at least 6/60 compared with 48% and 71% of the intact eyes respectively (both p >0.1). The proportion of keratoconic eyes which achieved at least 6/60 was lower (p = 0.02) in the ruptured eyes (67%) than the non-ruptured eyes (87%). Eyes with wound ruptures of 5 clock hours or greater were less likely (p <0.05) to achieve an acuity of 6/18 and were more likely (p <0.05) to have an associated lens injury. CONCLUSIONS: Graft rupture is relatively common in African practice, particularly in young keratoconics. Visual outcome and graft survival are not significantly worse than for other grafted eyes, but are significantly worse than for other grafted keratoconic eyes.

Extrafacial lentigo maligna melanoma: analysis of 71 cases and comparison with lentigo maligna melanoma of the head and neck.

We report a retrospective analysis of extrafacial lentigo maligna melanoma (LMM), and a comparison with patients with LMM of the head and neck. Seventy-one patients (22 men, 49 women) with extrafacial LMM were identified from the Scottish Melanoma Group database for January 1979-March 1996. Their mean age (63 years) was significantly less than that of 335 patients with head and neck LMM (mean 72 years, P < 0.001), with a significantly greater difference among women than men. Extrafacial sites comprised 17.5% of LMMs. There was a marked body site distribution difference between the sexes (P = 0. 001): 68% of extrafacial LMMs in men were on the trunk while 80% in women were on the limbs, particularly the lower leg. Extrafacial LMMs were thinner at presentation than head and neck LMMs (P < 0.05) in both sexes, but this was not simply explained by the younger age of these patients as there was no significant correlation between age and tumour thickness at either extrafacial or at head and neck sites. Although the female lower leg is a site of chronic solar exposure in older women, the other extrafacial sites are habitually covered in the temperate Scottish climate. The significantly younger age group of patients with LMM at extrafacial compared with head and neck sites therefore suggests that the relationship between LMM and sunlight is not simply related to cumulative solar exposure. The demonstration that head and neck LMMs were thicker at presentation compared with extrafacial sites, despite being at a more routinely visible part of the body, suggests that there are still opportunities for targeted pigmented lesion public education.

An inner city preschool visual screening programme: long-term visual results.

AIMS: The aim of this study was to investigate the long-term outcome of the treatment of amblyopia as a sequel to preschool screening, which has not hither-to been described. METHODS: All patients originally referred from a preschool screening programme were recalled for examination by letter. 255 patients were reviewed at least 4 years after discharge of which 88 were definitely amblyopic at presentation and 107 were not amblyopic at presentation and were used as controls. RESULTS: 79% of the amblyopes improved or maintained visual acuity after discharge but this was reduced to 42% after an age induced increase (estimated from the controls) was compensated for. The mean drop in visual acuity in the amblyopic eyes which deteriorated was 0.23 (SD 0.15) logMAR units. Stepwise multiple linear regression showed that the best single predictor of post-discharge deterioration in visual acuity was the improvement in visual acuity seen during treatment (R2 = 19%). Eccentric fixation at time of follow up (increasing R2 to 47%) and good presenting acuity (further raising R2 to 57%) contributed additional information, and were both associated with greater post-discharge deterioration in visual acuity. CONCLUSIONS: The majority of amblyopes who attended for follow up maintained or improved their visual acuities after discharge. Those patients who demonstrated deterioration of their amblyopia had usually improved well during the programme and were often fixating eccentrically at follow up.

Oral disease in terminally ill cancer patients with xerostomia.

Xerostomia is common among patients with advanced cancer and is likely to contribute to oral disease. This study determined the prevalence of oral signs and symptoms among a group of 70 terminally ill cancer patients [25 male, 45 female; age range 42-88 (mean 66) years] complaining of oral dryness, and examined the associated oral microflora. Imprint cultures for yeasts, coliforms and staphylococci were collected from the tongue and, in denture wearers, from the plate and denture fitting surface. A swab was collected for culture of herpes simplex virus. 68 patients (97%) complained of oral dryness during the day and 59 patients (84%) complained of oral dryness at night. Oral soreness was reported by 22 patients (31%). 46 patients (66%) had difficulty talking and 36 (51%) reported difficulty eating. Of the 56 denture wearers, 40% complained of denture problems. On examination, 63 (90%) of the patients had clinically dry mouths. Oral mucosal abnormalities were detected in 45 patients (65%), most commonly erythema (20%), coated tongue (20%), atrophic glossitis (17%), angular cheilitis (11%) and pseudomembraneous candidosis (9%). 47 (67%) of the patients carried yeasts, 18 (26%) were carriers of Staphylococcus aureus and 13 (19%) carried coliforms. Herpes simplex virus was isolated from 5 patients, of whom 2 had herpetic stomatitis. Oral complications and abnormalities of the oral microflora can be detected among significant numbers of terminally ill cancer patients with xerostomia.

The value of the coefficient of variation in assessing repeat variation in ECG measurements.

AIMS: The coefficient of variation is a popular measure for describing the amount of repeat variability present in ECG measurements from recording to recording. However, it can be misleading. The aim of the present study was to assess repeat variation (reclassification) in computer measured ECG criteria, i.e. positive to negative or vice versa, and compare this with the coefficient of variability. METHODS AND RESULTS: Two ECGs were obtained from each of 295 patients, one day apart, and separately from a further 364 patients, several minutes apart. All patients were considered to be in a stable condition. Estimates of the coefficients of variation were obtained for a number of ECG parameters used in the diagnosis of left ventricular hypertrophy. Corresponding reclassification rates of relevant ECG criteria were also calculated. Large coefficients of variation were observed in voltage parameters, e.g. R in V5 (20% for day-to-day recordings and 6% for minute-to-minute recordings) while the corresponding reclassification rates were 8% and 0% respectively. The repeat variation in the diagnosis of left ventricular hypertrophy was up to 5% for day-to-day recordings and up to 3% for minute-to-minute recordings based on several different criteria. CONCLUSION: A large coefficient of variation in a particular variable does not necessarily correspond to a high reclassification rate. A better measure of the impact of ECG variability for a particular measurement is obtained from its reclassification rate. In turn, this may have a minimal effect on the overall diagnosis of a particular abnormality.

Clinical trial of a mucin-containing oral spray for treatment of xerostomia in hospice patients.

Thirty-five hospice patients complaining of dry mouth entered a double-blind, single-phase placebo-controlled trial of a mucin-containing oral spray (Saliva Orthana) for the relief of xerostomia. The sprays were administered ad libitum for two weeks by the patients themselves, with nursing help as necessary. A detailed history and examination were undertaken, together with collection of microbiological specimens, at entry and after seven and 14 days of spray usage, respectively. Thirty-one patients were available for follow-up at seven days and 26 patients after 14 days. Relief of oral dryness during the day was reported by 9/15 patients on Saliva Orthana and 10/16 patients on placebo by day 7, with a similar degree of improvement maintained to day 14. The corresponding figures by day 7 for relief of dryness at night were 8/15 for Saliva Orthana and 8/16 for placebo. There were no statistically significant differences between those on active and those on placebo spray for any of the oral symptoms recorded. Neither spray had any major impact on the oral microflora. However, the majority of patients in both treatment groups wished to continue using a mouth spray at the end of their involvement in the trial. Whilst the data from this study provide no evidence for increased benefit of a mucin-containing spray over a mucin-free placebo among xerostomic hospice patients, it is clear that both sprays provided worthwhile symptomatic relief of oral dryness for many of the participants.