Describing the participants in a study.

This paper reviews the use of descriptive statistics to describe the participants included in a study. It discusses the practicalities of incorporating statistics in papers for publication in Age and Aging, concisely and in ways that are easy for readers to understand and interpret.

A randomized controlled feasibility trial exploring partnered ballroom dancing for people with Parkinson's disease.

OBJECTIVE: To determine the feasibility of a Dance Centre delivering a programme of mixed dances to people with Parkinson's and identify suitable outcomes for a future definitive trial. DESIGN: A two-group randomized controlled feasibility trial. METHODS: People with Parkinson's were randomized to a control or experimental group (ratio 15:35), alongside usual care. In addition, participants in the experimental group danced with a partner for one hour, twice-a-week for 10 weeks; professional dance teachers led the classes and field-notes were kept. Control-group participants were given dance class vouchers at the end of the study. Blinded assessments of balance, mobility and function were completed in the home. Qualitative interviews were conducted with a subsample to explore the acceptability of dance. RESULTS: A total of 51 people with Parkinson's (25 male) with Hoehn and Yahr scores of 1-3 and mean age of 71 years (range 49-85 years), were recruited to the study. Dance partners were of similar age (mean 68, range 56-91 years). Feasibility findings focused on recruitment (target achieved); retention (five people dropped out of dancing); outcome measures (three measures were considered feasible, changes were recommended). Proposed sample size for a Phase III trial, based on the 6-minute walk test at six months was 220. Participants described dance as extremely enjoyable and the instructors were skilled in instilling confidence and motivation. The main organizational challenges for a future trial were transport and identifying suitable dance partners. CONCLUSION: We have demonstrated the feasibility of conducting the study through a Dance Centre and recommend a Phase III trial.

Test-retest reliability of the oxygen uptake efficiency slope in surgical patients.

The oxygen uptake efficiency slope is a measure of cardiopulmonary fitness, that can be obtained from a sub-maximal cardiopulmonary exercise test. It has been evaluated in medical patients but its reliability in surgical populations remains uncertain. We conducted a test-retest study with the aim of establishing the reliability of the oxygen uptake efficiency slope in relation to that of the anaerobic threshold and peak oxygen uptake, in general surgical patients. Twenty-six patients over 60 years old completed two symptom-limited, incremental cycle ergometry tests within 7 days. The mean (SD) anaerobic threshold was 13.0 (3.0) mlO(2) .kg(-1) .min(-1) . There were no significant differences between mean test and retest values of anaerobic threshold (p = 0.50), peak oxygen uptake (p = 0.76) or oxygen uptake efficiency slope (p = 0.42). Reliability coefficients (95% CI) for the anaerobic threshold, oxygen uptake efficiency slope and peak oxygen uptake were 66.7% (45.3-87.9%), 89.0% (81.0-96.9%) and 91.7% (85.7-97.8%), respectively. The oxygen uptake efficiency slope was determined easily in all patients and found to have excellent reliability. Its clinical utility in determining pre-operative fitness warrants further evaluation.

An open randomized comparison of clinical effectiveness of protocol-driven opioid analgesia, celiac plexus block or thoracoscopic splanchnicectomy for pain management in patients with pancreatic and other abdominal malignancies.

UNLABELLED: In inoperable malignancy, pain relief with opioids is often inadequate. Nerve block procedures may improve symptom control. Our aim was to assess celiac plexus block (CPB) and thoracoscopic splanchnicectomy (TS) in patients receiving appropriate medical management (MM). METHODS: Patients with confirmed irresectable malignancy of the pancreas or upper abdominal viscera who required opioid analgesia were randomized to MM alone, MM+CPB, or MM+TS. Randomization was stratified by treatment centre, tumour type and previous opioid medication. The primary endpoint was pain relief at 2 months. RESULTS: 65 patients (58 pancreas cancer) were randomized, 18 withdrew or died within 2 months. Effective pain relief was achieved in only one third of subjects at 2 weeks, and just under half at 2 months (MM: 6/19 and 5/12 evaluable patients; CPB: 5/14 and 5/9; TS 4/14 and 4/11). There were no significant differences between the groups in pain scores or opioid consumption, and there was no correlation between continued use of opioids and effective pain relief. DISCUSSION: Previous randomized studies have shown small differences in pain scores, but no difference in opioid consumption and quality of life. The absence of any benefit from interventions in the present study questions their value.

Consequence of Abeta immunization on the vasculature of human Alzheimer's disease brain.

A major feature of Alzheimer's disease is the accumulation of amyloid-beta peptide (Abeta) in the brain both in the form of plaques in the cerebral cortex and in blood vessel as cerebral amyloid angiopathy (CAA). Experimental models and human clinical trials have shown that accumulation of Abeta plaques can be reversed by immunotherapy. In this study, we hypothesized that Abeta in plaques is solubilized by antibodies generated by immunization and drains via the perivascular pathway, detectable as an increase in cerebrovascular Abeta. We have performed a follow up study of Alzheimer's disease patients immunized against Abeta42. Neuropathological examination was performed on nine patients who died between four months and five years after their first immunization. Immunostaining for Abeta40 and Abeta42 was quantified and compared with that in unimmunized Alzheimer's disease controls (n = 11). Overall, compared with these controls, the group of immunized patients had approximately 14 times as many blood vessels containing Abeta42 in the cerebral cortex (P<0.001) and seven times more in the leptomeninges (P = 0.013); among the affected blood vessels in the immunized cases, most of them had full thickness and full circumference involvement of the vessel wall in the cortex (P = 0.001), and in the leptomeninges (P = 0.015). There was also a significantly higher level of cerebrovascular Abeta40 in the immunized cases than in the unimmunized cases (cortex: P = 0.009 and leptomeninges: P = 0.002). In addition, the immunized patients showed a higher density of cortical microhaemorrhages and microvascular lesions than the unimmunized controls, though none had major CAA-related intracerebral haemorrhages. The changes in cerebral vascular Abeta load did not appear to substantially influence the structural proteins of the blood vessels. Unlike most of the immunized patients, two of the longest survivors, four to five years after first immunization, had virtually complete absence of both plaques and CAA, raising the possibility that, given time, Abeta is eventually cleared from the cerebral vasculature. The findings are consistent with the hypothesis that Abeta immunization results in solubilization of plaque Abeta42 which, at least in part, exits the brain via the perivascular pathway, causing a transient increase in the severity of CAA. The extent to which these vascular alterations following Abeta immunization in Alzheimer's disease are reflected in changes in cognitive function remains to be determined.

The influence of attention deficits on functional recovery post stroke during the first 12 months after discharge from hospital.

BACKGROUND: Attention deficits have been linked to poor recovery after stroke and may predict outcome. We explored the influence of attention on functional recovery post stroke in the first 12 months after discharge from hospital. METHODS: People with stroke completed measures of attention, balance, mobility and activities of daily living (ADL) ability at the point of discharge from hospital, and 6 and 12 months later. We used correlational analysis and stepwise linear regression to explore potential predictors of outcome. RESULTS: We recruited 122 men and women, mean age 70 years. At discharge, 56 (51%) had deficits of divided attention, 45 (37%) of sustained attention, 43 (36%) of auditory selective attention and 41 (37%) had visual selective attention deficits. Attention at discharge correlated with mobility, balance and ADL outcomes 12 months later. After controlling for the level of the outcome at discharge, correlations remained significant in only five of the 12 relationships. Stepwise linear regression revealed that the outcome measured at discharge, days until discharge and number of medications were better predictors of outcome: in no case was an attention variable at discharge selected as a predictor of outcome at 12 months. CONCLUSIONS: Although attention and function correlated significantly, this correlation was reduced after controlling for functional ability at discharge. Furthermore, side of lesion and the attention variables were not demonstrated as important predictors of outcome 12 months later.

Invasiveness of cutaneous malignant melanoma is influenced by matrix metalloproteinase 1 gene polymorphism.

The matrix metalloproteinases (MMPs) are implicated in connective tissue destruction during cancer invasion and metastasis. A naturally occurring variant arising from the insertion or deletion of a guanine in the promoter of the MMP-1 gene has recently been reported and shown to influence its transcriptional activity in melanoma cells. In this study, MMP-1 genotype was determined in 139 Caucasian patients with cutaneous malignant melanoma. The insertion allele was associated with deep invasive, and therefore poorer-prognosis, primary tumors [(34% of patients with vertical growth phase tumor were homozygous for the insertion allele compared with 17% of patients with horizontal growth phase tumor (P = 0.0333; odds ratio = 2.51)]. These data suggest that the invasiveness of cutaneous malignant melanoma is influenced by variation in the MMP-1 gene promoter that affects MMP-1 expression.

Multiple sessions of transcranial direct current stimulation and upper extremity rehabilitation in stroke: A review and meta-analysis.

OBJECTIVE: To systematically review the methodology in particular treatment options and outcomes and the effect of multiple sessions of transcranial direct current stimulation (tDCS) with rehabilitation programmes for upper extremity recovery post stroke. METHODS: A search was conducted for randomised controlled trials involving tDCS and rehabilitation for the upper extremity in stroke. Quality of included studies was analysed using the Modified Downs and Black form. The extent of, and effect of variation in treatment parameters such as anodal, cathodal and bi-hemispheric tDCS on upper extremity outcome measures of impairment and activity were analysed using meta-analysis. RESULTS: Nine studies (371 participants with acute, sub-acute and chronic stroke) were included. Different methodologies of tDCS and upper extremity intervention, outcome measures and timing of assessments were identified. Real tDCS combined with rehabilitation had a small non-significant effect of +0.11 (p=0.44) and +0.24 (p=0.11) on upper extremity impairments and activities at post-intervention respectively. CONCLUSION: Various tDCS methods have been used in stroke rehabilitation. The evidence so far is not statistically significant, but is suggestive of, at best, a small beneficial effect on upper extremity impairment. SIGNIFICANCE: Future research should focus on which patients and rehabilitation programmes are likely to respond to different tDCS regimes.

Risks of delivery during the 20th to the 36th week of gestation.

Using routinely collected maternity discharge data from 250,000 women in Scotland, we examined the risks of late spontaneous abortion and preterm delivery during the period 20 up to 36 weeks of gestation. Gestational age is treated as a fetal survival time and the risks of delivery associated with a history of spontaneous abortion, induced abortion and perinatal death are examined in a survival model controlling for several demographic and socioeconomic variables. The main objective of the study is to identify factors which are associated with high relative hazard of delivery early in the period, but with decreasing relative hazard of delivery as pregnancy progresses. The factor most clearly associated with converging hazards is a history of two or more spontaneous abortions, and this may reflect the tendency to repeat pregnancy outcome.

Orthotopic heart transplantation in children with congenital heart disease.

The early experience (February 1982 to June 1988) with transplantation for the treatment of congenital heart disease at the University of Pittsburgh was disappointing due to an excessively high perioperative mortality. From July 1988 to June 1992, a further 21 children with congenital heart disease underwent orthotopic transplantation. Thirteen had undergone multiple prior palliative procedures (mean, 2.8 per patient). In 12 of these patients, prior procedures involved the pulmonary arteries on one or more occasions. In contrast to our earlier experience, there were no deaths stemming from inadequate surgical reconstruction or pulmonary hypertension. The actuarial survival was 71% at both 1 and 3 years. This did not differ significantly from the survival among 18 patients who underwent transplantation for the management of cardiomyopathy over the same period (1-year and 3-year survival, 83%). The perioperative mortality and short-term survival are now similar for children undergoing transplantation for the treatment of either congenital heart disease or cardiomyopathy. These improved results probably reflect more careful patient selection and an increasing surgical experience with complex reconstructive procedures.

Relative risks of low birthweight in Scotland 1980-2.

Routinely collected data for 187,000 Scottish singleton livebirths in 1980-2 were used to relate the risk of birthweight below 2500 g, 2000 g, 1500 g, and 1000 g to sex of infant and nine maternal factors. Maternal height was a major predictor of birthweight below 2500g but was less important in predicting birthweight in the lower intervals. A history of prenatal death and spontaneous abortion was important for all four intervals and was associated with most extreme risks for birthweight below 1000 g. The analysis confirms that the patterns of risk of birthweight below 2500g and 2000 g associated with social class, marital status, and maternal age and height found among the women of the 1958 cohort of British births are still applicable in the early 1980s.

Importance of district of residence and known primary site for bowel cancer survival: analysis of data from Wessex Cancer Registry.

STUDY OBJECTIVE: The aim was to compare survival with colon and rectal cancer across the 10 districts of Wessex taking into account the age and sex of the individual. DESIGN: The study was based on registrations on the Wessex Cancer Registry between 1979 and 1984 with colon and rectal cancer. Survival up to 31 December 1986 was examined using a Cox regression model; individuals surviving to the end of the follow up period were treated as censored in the analysis. Survival was examined in the first fortnight, the first month, and the first six months after registration separately. PARTICIPANTS: The data comprised 6239 residents of the Wessex Region who had been diagnosed with colon cancer and 3203 residents diagnosed with rectal cancer. For 140 cases survival data or age were missing and these cases were excluded. MEASUREMENTS AND MAIN RESULTS: Results are presented in the format of a league table giving the order of districts from lowest to highest survival rates. No significant differences in survival are found between districts in relation to rectal cancer. We find that one or two districts have consistently high or low survival rates with colon cancer in various periods of follow up, but cannot differentiate between the districts in the centre of the list. Site unspecified is considered as an explanatory variable; it is more predictive than district, and it approaches the importance of age in explaining survival with colon cancer. CONCLUSIONS: There are significant differences in survival with colon cancer between districts; however data on stage at registration are not available and we are unable to say whether the differences in survival are due to differences in stage at diagnosis or differences in survival with similar stage at diagnosis. We found that cases where the site of the cancer within the colon was not recorded on the register have significantly lower survival, and we suggest that site unspecified may be related to stage at diagnosis.

Comparative study of mortality rates and cardiac dysrhythmias in post-marketing surveillance studies of sertindole and two other atypical antipsychotic drugs, risperidone and olanzapine.

Sertindole (Serdolect), an atypical antipsychotic, was voluntarily suspended in the European Union in 1998 following regulatory concerns over reports of serious cardiac dysrhythmias and sudden unexpected deaths. The reported causes of death, their frequency, prolongation of the rate corrected QT interval (QTc) and cardiac dysrhythmias in patients prescribed sertindole were compared with those for patients treated with two other atypical antipsychotics. All patients in England, prescribed atypical antipsychotics by general practitioners during each drug's immediate post-marketing period, were identified using an observational cohort technique, prescription-event monitoring. Mortality rates in the sertindole cohort were compared with those in a comparator cohort using standardized mortality ratios and incidence rate ratios. Cardiovascular events were reviewed and followed up to identify cases of prolongation of QTc interval. There was no statistically significant difference in mortality rates between sertindole and the comparator cohort, although confidence intervals (CI) were wide due to small numbers in the sertindole cohort. A much smaller number of patients were prescribed sertindole than the other antipsychotics. Six cases of prolongation of QTc interval were identified in 462 patients (1.3%, 95% CI 0.5-2.8) treated with sertindole and one with unspecified electrocardiogram changes in the comparator cohort of 16,542 patients. This study contributes to the understanding of the occurrence of prolongation of QTc interval during clinical use of sertindole, the incidence of which was similar to that in clinical trials. Although no statistically significant difference was shown in mortality rates between sertindole and comparator cohort, the sertindole cohort was too small to rule out an association between the use of this drug and cardiovascular deaths.

A randomized trial to assess the efficacy of 5-aminosalicylic acid for the prevention of radiation enteritis.

Sulphasalazine is an effective treatment for diarrhoea occurring during pelvic radiotherapy. We report the results of a trial to assess the value of its active moiety, 5-aminosalicylic acid, (5-ASA) in a prophylactic setting. Seventy-three patients planned for external beam radiotherapy to the pelvis were randomized on a double-blind basis to receive prophylactic 5-ASA or placebo. The severity of the acute radiation bowel reaction was documented by a weekly questionnaire. Surprisingly, diarrhoea occurred in a higher proportion of patients in the 5-ASA arm than the placebo arm (91.2% versus 73.7%, P = 0.070). The maximum change in both the severity of diarrhoea and the number of days per week on which diarrhoea occurred (from pre-radiotherapy level to the worst level at any time during treatment) were both significantly greater in patients taking 5-ASA than those taking placebo (P = 0.014 and P = 0.026, respectively). The average change (the sum of the weekly scores divided by the number of weeks of treatment, minus the pre-radiotherapy score) for both severity and days per week of diarrhoea were again greater in the 5-ASA than the placebo arm, but failed to reach statistical significance (P = 0.095 and P = 0.079, respectively). The use of anti-diarrhoeal medicines was significantly greater in the 5-ASA arm (P = 0.011). Constipation was more common in the placebo arm but this did not reach significance (P = 0.20). 5-ASA thus has no protective effect against acute radiation enteritis and appears to worsen it. Possible reasons for this surprising finding are discussed.

Indices of apoptosis and proliferation as potential prognostic markers in non-functioning pituitary adenomas.

OBJECTIVE: Non-functioning pituitary adenomas (NFAs) are a distinct group of pituitary adenomas, which comprise approximately 20% of pituitary adenomas. Although most pituitary adenomas are benign, there is a subset of adenomas that behaves in an aggressive fashion, with either invasion of the surrounding structures or recurrence. The aim of this study was to investigate whether the behaviour of NFAs can be predicted using immunohistochemical markers that label proliferating and apoptotic cells, including a new marker for apoptosis (M30 CytoDEATH). This is the first study to analyse both the proliferation labelling index (LI) and the apoptotic index (AI) in NFAs and to correlate the labelling indices of these histological markers with tumor growth rate as measured by 2 postoperative MRI scans. MATERIAL AND METHODS: 40 patients in total were included in the study. 20 patients with high growth rate and percentage change in the pituitary adenoma volume as assessed on 2 postoperative MRI scans were age/sex matched to 20 patients with low growth rate or percentage change. RESULTS: There is no significant statistical difference of the histological and immunohistochemical indices assessed between cases and controls. CONCLUSION: The routine assessment of the proliferation and the apoptotic markers used in this study in NFAs has no prognostic value.

What is the normal pattern of uterine involution? An investigation of postpartum uterine involution measured by the distance between the symphysis pubis and the uterine fundus using a paper tape measure.

OBJECTIVE: To describe normal postnatal uterine involution in a small sample of healthy primiparous women, and estimate the proportion who have a decline in the distance between the symphysis pubis and the uterine fundus (S-FD) slow enough to have the potentiality to trigger further clinical action, using currently accepted criteria for intervention. SETTING: A maternity unit in the south of England that has approximately 6000 deliveries per annum and the related community areas. METHODS: Daily measurement of the S-FD was carried out in 28 healthy women from within 18 hours of delivery until the uterine fundus was no longer palpable abdominally. Graphs showing the daily measurements and correlation coefficients were used to describe involution. The proportion of healthy women who would have been identified as healthy by the screening method was estimated (its specificity). FINDINGS: Considerable variability was found in the pattern of uterine involution that was experienced by the women who had a normal puerperium. The measurement of the S-FD has a low specificity with only 6 of the 28 women (21.4%; 95% CI 8.3% to 40.9% having had no episodes of the S-FD declining slowly (less than 1 cm over three days). There was a weak, positive correlation between the S-FD measurement on day one and the day on which the uterus ceased to be palpable (r = 0.426, P = 0.03). No relationship was found between method of baby feeding and the day on which the uterus ceased to be palpable. IMPLICATIONS FOR PRACTICE: The measurement of S-FD using a paper tape measure should not form part of routine postpartum assessment.

Is measuring postnatal symphysis-fundal distance worthwhile?

OBJECTIVE: to assess levels of intra-observer and inter-observer variability in the measurement of postnatal symphysis-fundal distance and establish whether the measurement is sufficiently precise for it to be of use in clinical practice. SETTING: a consultant obstetric maternity unit in the south of England which caters for approximately 6000 deliveries per annum. METHODS: in the intra-observer study 15 midwives took repeated readings of symphysis-fundal distance on 30 postnatal women. In the inter-observer study 13 midwives took readings of symphysis-fundal distances on 24 postnatal women. Repeatability coefficients (the variability to be expected in the change between two measurements) were calculated. FINDINGS: the repeatability coefficient, that is the maximum difference that is likely to occur, 95% of the time, for the difference between two measurements obtained by the same midwife on the same woman is 2.94 cm (intra-observer study). Where measurements are obtained by different midwives on the same mother the repeatability coefficient is 5.01 cm (inter-observer study). In everyday clinical practice variability is likely to be greater than that found in this study. IMPLICATIONS FOR PRACTICE: the daily measurement of the postnatal symphysis-fundal distance with a tape measure cannot be obtained with enough precision to be useful in making clinical judgements and therefore should be discontinued. Further research is required to assess the value of routine palpation of the uterine fundus to assess involution during the postnatal period.

An investigation into the feasibility of comparing three management options (augmentation, conservative and water) for nulliparae with dystocia in the first stage of labour.

OBJECTIVE: to evaluate the feasibility of a randomised controlled trial (RCT) examining the effect of three options (augmentation, conservative and water) for the management of dystocia in nulliparae. The main objectives were to explore the feasibility of trial procedures in the clinical environment, consent rates and acceptability of the management options to women, local incidence of dystocia in nulliparae and the size of the subsequent study. DESIGN: a two part study: a pilot, RCT with follow-up through to delivery with postnatal maternal surveys, and a case review of nulliparae with dystocia. SETTING: a large maternity unit in the South of England in May-July 1997 inclusive. PARTICIPANTS: nulliparae with dystocia in the first stage of labour who had an otherwise uncomplicated obstetric background. INTERVENTIONS: women in the pilot RCT received one of three management options: labouring in a waterbirth pool, conservative management or augmentation of labour, which is the standard management of women with dystocia condition in the Unit. FINDINGS: it is feasible to conduct an RCT of management of dystocia in the Unit. Seventy per cent (95% confidence interval 47% to 87%) of women approached agreed to participate. Conservative management was the least acceptable option to women and has been dropped from the subsequent trial. The audit provided some idea of possible differences in operative delivery and epidural rates depending on augmentation or not. A sample of 220 women should be large enough to detect moderate changes and will require a 2-year recruitment period. CONCLUSIONS: a subsequent trial is feasible and is now underway. It has the potential to provide information enabling women and practitioners to have a greater choice of care options in the presence of dystocia, or provide a good basis for an even larger trial.

Thromboembolic deterrent stockings fail to prevent hypotension associated with spinal anaesthesia for elective caesarean section.

This study was carried out to determine whether the use of thrombo-embolic deterrent (TED) stockings, in combination with an intravenous crystalloid preload, would prevent hypotension following spinal anaesthesia for caesarean section. Fifty parturients undergoing elective caesarean section under spinal anaesthesia were randomly allocated into two groups. TED stockings were applied to the study group 1 h before spinal anaesthesia but none were applied to the control group. Both groups received a crystalloid preload of 15 ml kg(-1) over 15 min before spinal injection. Significant hypotension, defined as an absolute value of systolic arterial pressure (SAP) of less than 90 mmHg and a decrease of more than 20% from baseline SAP was treated with 3 mg bolus of ephedrine as required. The difference in SAO between the two groups was not statistically significant. In the control group, 80% of parturients required ephedrine as opposed to 56% in the TED group; a difference that was also not statistically significant.

Biochemical diagnosis of ventricular dysfunction in elderly patients in general practice: observational study.

OBJECTIVE: To investigate the usefulness of measuring plasma concentrations of B type natriuretic peptide in the diagnosis of left ventricular systolic dysfunction in an unselected group of elderly people. DESIGN: Observational study. SETTING: General practice with four centres in Poole, Dorset. PARTICIPANTS: 155 elderly patients aged 70 to 84 years. MAIN OUTCOME MEASURES: Diagnostic characteristics of plasma B type natriuretic peptide measured by radioimmunoassay as a test for left ventricular systolic dysfunction assessed by echocardiography. RESULTS: The median plasma concentration of B type natriuretic peptide was 39.3 pmol/l in patients with left ventricular systolic dysfunction and 15.8 pmol/l in those with normal function. The proportional area under the receiver operator curve was 0.85. At a cut-off point of 18.7 pmol/l the test sensitivity was 92% and the predictive value 18%. CONCLUSIONS: Plasma concentration of B type natriuretic peptide could be used effectively as an initial test in a community screening programme and, possibly, using a low cut-off point, as a means of ruling out left ventricular systolic dysfunction. It is, however, not a good test to "rule in" the diagnosis, and access to echocardiography remains essential for general practitioners to diagnose heart failure early.