Biomedical subjects

Jonathan A C Sterne

Publications and source records attributed to Jonathan A C Sterne.

At least 19 recordsLinked to original sources

PubMed2006

A modified test for small-study effects in meta-analyses of controlled trials with binary endpoints.

Publication bias and related bias in meta-analysis is often examined by visually checking for asymmetry in funnel plots of treatment effect against its standard error. Formal statistical tests of funnel plot asymmetry have been proposed, but when applied to binary outcome data these can give false-positive rates that are higher than the nominal level in some situations (large treatment effects, or few events per trial, or all trials of similar sizes). We develop a modified linear regression test for funnel plot asymmetry based on the efficient score and its variance, Fisher's information. The performance of this test is compared to the other proposed tests in simulation analyses based on the characteristics of published controlled trials. When there is little or no between-trial heterogeneity, this modified test has a false-positive rate close to the nominal level while maintaining similar power to the original linear regression test ('Egger' test). When the degree of between-trial heterogeneity is large, none of the tests that have been proposed has uniformly good properties.

Endpoint Determination↗

PubMed2006

Vulvovaginal-swab or first-catch urine specimen to detect Chlamydia trachomatis in women in a community setting?

Screening for chlamydia in women is widely recommended. We evaluated the performance of two nucleic acid amplification tests for detecting Chlamydia trachomatis in self-collected vulvovaginal-swab and first-catch urine specimens from women in a community setting and a strategy for optimizing the sensitivity of an amplified enzyme immunoassay on vulvovaginal-swab specimens. We tested 2,745 paired vulvovaginal-swab and urine specimens by PCR (Roche Cobas) or strand displacement amplification (SDA; Becton Dickinson). There were 146 women infected with chlamydia. The assays detected 97.3% (95% confidence interval [CI], 93.1 to 99.2%) of infected patients with vulvovaginal-swab specimens and 91.8% (86.1 to 95.7%) with urine specimens. We tested 2,749 vulvovaginal-swab specimens with both a nucleic acid amplification test and a polymer conjugate-enhanced enzyme immunoassay with negative-gray-zone testing. The relative sensitivities obtained after retesting specimens in the negative gray zone were 74.3% (95% CI, 62.8 to 83.8%) with PCR and 58.3% (95% CI, 46.1 to 69.8%) with SDA. In community settings, both vulvovaginal-swab and first-catch urine specimens from women are suitable substrates for nucleic acid amplification tests, but enzyme immunoassays, even after negative-gray-zone testing, should not be used in screening programs.

Adolescent↗

PubMed2006

Combining individual and ecological data to determine compositional and contextual socio-economic risk factors for suicide.

The social and economic characteristics of geographic areas are associated with their suicide rates. The extent to which these ecological associations are due to the characteristics of the people living in the areas (compositional effects) or the influence of the areas themselves on risk (contextual effects) is uncertain. Denmark's Medical Register on Vital Statistics and its Integrated Database for Longitudinal Labour Market Research were used to identify suicides and 20 matched controls per case in 25-60-year-old men and women between 1982 and 1997. Individual and area (municipality) measures of income, marital and employment status were obtained. There were 9011 suicides and 180,220 controls. Individual-level associations with these risk factors were little changed when controlling for contextual effects. In contrast, ecological associations of increased suicide risk with declining area levels of employment and income and increasing proportions of people living alone were much attenuated after controlling for compositional effects. We found no consistent evidence that associations with individual-level risk factors differed depending on the areas' characteristics (cross-level interactions). This analysis suggests the ecological associations to be attributed to characteristics of the residents rather than area influences on risk.

Adult↗

PubMed2006

Association of childhood socioeconomic position with cause-specific mortality in a prospective record linkage study of 1,839,384 individuals.

Previous studies have lacked sufficient power to assess associations between early-life socioeconomic position and adult cause-specific mortality. The authors examined associations of parental social class at age 0-16 years with mortality among 1,824,064 Swedes born in 1944-1960. Females and males from manual compared with nonmanual childhood social classes were more likely to die from smoking-related cancers, stomach cancer, respiratory disease, cardiovascular disease, and diabetes. Males from manual compared with nonmanual social classes were more likely to die from unintentional injury, homicide, and alcoholic cirrhosis. The association with stomach cancer was little affected by adjustment for parental later-life and own adult social class or education. For other outcomes, educational attainment resulted in greater attenuation of associations than did adjustment for adult social class. Early-life social class was not related to suicide or to melanoma, colon, breast, brain, or lymphatic cancers or to leukemia. With the exception of stomach cancer, caused by Helicobacter pylori infection acquired in childhood, poorer social class in early life was associated with diseases largely caused by behavioral risk factors such as smoking, physical inactivity, and an unhealthy diet. Educational attainment may be important in reducing the health inequalities associated with early-life disadvantage.

Cause of Death↗

PubMed2006

The publication process itself was the major cause of publication bias in genetic epidemiology.

OBJECTIVES: How do scientists in the field of genetic epidemiology see the problem of publication bias, what are the possible solutions and what particular pressures are they under that might either promote or prevent publication and other biases? STUDY DESIGN AND SETTING: An exploratory study of beliefs and practices among scientists working in the field of genetic epidemiology. A purposive sample of senior, genetic scientists was selected (N=6) and informants were interviewed face to face. RESULTS: There was some consensus that the issue of nonreplication might be particularly problematic in genetic epidemiology, and that publication bias could contribute to this. The informants suggested that the problem lay mainly with the publication process. Publication of negative results was seen as important but fraught with difficulties. CONCLUSION: Possible solutions included education of editors, and reviewers, dissemination of negative findings through Web sites or accessible data archives and pooling of data. However, none of these were perceived to be straightforward given the current pressures on the research industry.

Culture↗

PubMed2006

HIV treatment response and prognosis in Europe and North America in the first decade of highly active antiretroviral therapy: a collaborative analysis.

BACKGROUND: Highly active antiretroviral therapy (HAART) for the treatment of HIV infection was introduced a decade ago. We aimed to examine trends in the characteristics of patients starting HAART in Europe and North America, and their treatment response and short-term prognosis. METHODS: We analysed data from 22,217 treatment-naive HIV-1-infected adults who had started HAART and were followed up in one of 12 cohort studies. The probability of reaching 500 or less HIV-1 RNA copies per mL by 6 months, and the change in CD4 cell counts, were analysed for patients starting HAART in 1995-96, 1997, 1998, 1999, 2000, 2001, and 2002-03. The primary endpoints were the hazard ratios for AIDS and for death from all causes in the first year of HAART, which were estimated using Cox regression. RESULTS: The proportion of heterosexually infected patients increased from 20% in 1995-96 to 47% in 2002-03, and the proportion of women from 16% to 32%. The median CD4 cell count when starting HAART increased from 170 cells per muL in 1995-96 to 269 cells per muL in 1998 but then decreased to around 200 cells per muL. In 1995-96, 58% achieved HIV-1 RNA of 500 copies per mL or less by 6 months compared with 83% in 2002-03. Compared with 1998, adjusted hazard ratios for AIDS were 1.07 (95% CI 0.84-1.36) in 1995-96 and 1.35 (1.06-1.71) in 2002-03. Corresponding figures for death were 0.87 (0.56-1.36) and 0.96 (0.61-1.51). INTERPRETATION: Virological response after starting HAART improved over calendar years, but such improvement has not translated into a decrease in mortality.

Adolescent↗

PubMed2006

Nutritional interventions and outcome in patients with cancer or preinvasive lesions: systematic review.

BACKGROUND: Dietary modifications and supplements are used widely by patients with cancer and preinvasive lesions as an adjunct to standard treatment. Given the widespread use of nutritional modifications and supplements by such patients and concerns about the lack of benefit and possible harm, we conducted a systematic review of randomized controlled trials to examine the effect of nutritional interventions on patients with cancer or preinvasive lesions. METHODS: We searched electronic databases and reference lists to locate all eligible trials and analyzed trial quality. Outcome measures were all-cause and cancer mortality, disease-free survival, cancer recurrence, second primary cancer, recurrence of a preinvasive lesion, or progression to cancer. Results of individual trials were combined by use of random-effects meta-analyses. RESULTS: We identified 59 eligible trials, 25 in patients with cancer and 34 in patients with preinvasive lesions, respectively. Trial quality was generally low; only three trials (two of cancer and one of preinvasive lesions) had adequate methods for generating the allocation sequence, allocation concealment, and masking both outcome assessors and participants. The combined odds ratio (OR) for the effect of a healthy diet-given alone or with dietary supplements, weight loss, or exercise-on all-cause mortality was 0.90 (95% confidence interval [CI] = 0.46 to 1.77). There was no evidence of an association between the use of antioxidant (OR = 1.01, 95% CI = 0.88 to 1.15) or retinol (OR = 0.97, 95% CI = 0.83 to 1.13) supplements and all-cause mortality. Meta-analyses of all other outcomes did not show clear evidence of benefit or harm. CONCLUSIONS: The impact of most nutritional interventions cannot be reliably estimated because of the limited number of trials, many of which were of low quality. There is no evidence that dietary modification by cancer patients improves survival and benefits disease prognosis.

Antioxidants↗

PubMed2006

A unification of models for meta-analysis of diagnostic accuracy studies.

Studies of diagnostic accuracy require more sophisticated methods for their meta-analysis than studies of therapeutic interventions. A number of different, and apparently divergent, methods for meta-analysis of diagnostic studies have been proposed, including two alternative approaches that are statistically rigorous and allow for between-study variability: the hierarchical summary receiver operating characteristic (ROC) model (Rutter and Gatsonis, 2001) and bivariate random-effects meta-analysis (van Houwelingen and others, 1993), (van Houwelingen and others, 2002), (Reitsma and others, 2005). We show that these two models are very closely related, and define the circumstances in which they are identical. We discuss the different forms of summary model output suggested by the two approaches, including summary ROC curves, summary points, confidence regions, and prediction regions.

Diagnostic Tests, Routine↗

PubMed2006

A comparison of socio-demographic and psychological factors between patients consenting to randomisation and those selecting treatment (the ProtecT study).

BACKGROUND: Patient preferences for treatment can pose problems for the conduct of randomised controlled trials: patients with a preference may refuse participation and thereby potentially compromise external validity. Moreover, randomising patients with a preference may affect treatment efficacy and threaten internal validity. AIMS: This study compared baseline characteristics and short-term psychological outcomes of patients who selected their treatment and those who agreed to random allocation. METHODS: Men participating in the prostate testing for cancer and treatment (ProtecT) study and who were randomised to active monitoring (n=138) were compared with those who had refused randomisation and selected this management (n=180). Socio-demographic data were collected at baseline, and anxiety and depression data were collected at baseline and six month follow-up. Socio-demographic characteristics were compared across these two groups in univariable analyses, and then linear regression was used to compare levels of anxiety and depression at follow-up with adjustments for confounders. RESULTS: Participants who selected active monitoring were more affluent (based on occupation details) and had less anxiety at baseline than those who were randomised. There were no differences with respect to age and marital status. Levels of anxiety and depression at six months follow-up were similar across the two groups of men. CONCLUSIONS: This study found some differences at baseline between the socio-demographic and psychological status of those randomised and self-selecting treatment, but no psychological differences at short-term follow-up. Further empirical evidence is required to assess whether preferences impact upon the process and outcome of randomised controlled trials.

Aged↗

PubMed2006

Oxycodone for cancer-related pain: meta-analysis of randomized controlled trials.

To evaluate the efficacy and tolerability of oxycodone in cancer-related pain, we conducted a systematic review of randomized controlled trials. Four studies, comparing oral oxycodone with either oral morphine (n = 3) or oral hydromorphone (n = 1), were suitable for meta-analysis. Standardized mean differences in pain scores comparing oxycodone with control groups were pooled using random-effects models. Overall, there was no evidence that mean pain scores differed between oxycodone and control drugs (pooled standardized mean difference, 0.04; 95% confidence interval [CI], -0.29 to 0.36; P = .8; I(2) = 62%). In meta-regression analyses, pain scores were higher for oxycodone compared with morphine (0.20; 95% CI, -0.04 to 0.44) and lower compared with hydromorphone (-0.36; 95% CI, -0.71 to 0.00), although these effect sizes were small. The efficacy and tolerability of oxycodone are similar to morphine, supporting its use as an opioid for cancer-related pain.

Analgesics, Opioid↗

PubMed2006

Accuracy of magnetic resonance imaging for the diagnosis of multiple sclerosis: systematic review.

OBJECTIVE: To determine the accuracy of magnetic resonance imaging criteria for the early diagnosis of multiple sclerosis in patients with suspected disease. DESIGN: Systematic review. DATA SOURCES: 12 electronic databases, citation searches, and reference lists of included studies. Review methods Studies on accuracy of diagnosis that compared magnetic resonance imaging, or diagnostic criteria incorporating such imaging, to a reference standard for the diagnosis of multiple sclerosis. RESULTS: 29 studies (18 cohort studies, 11 other designs) were included. On average, studies of other designs (mainly diagnostic case-control studies) produced higher estimated diagnostic odds ratios than did cohort studies. Among 15 studies of higher methodological quality (cohort design, clinical follow-up as reference standard), those with longer follow-up produced higher estimates of specificity and lower estimates of sensitivity. Only two such studies followed patients for more than 10 years. Even in the presence of many lesions (> 10 or > 8), magnetic resonance imaging could not accurately rule multiple sclerosis in (likelihood ratio of a positive test result 3.0 and 2.0, respectively). Similarly, the absence of lesions was of limited utility in ruling out a diagnosis of multiple sclerosis (likelihood ratio of a negative test result 0.1 and 0.5). CONCLUSIONS: Many evaluations of the accuracy of magnetic resonance imaging for the early detection of multiple sclerosis have produced inflated estimates of test performance owing to methodological weaknesses. Use of magnetic resonance imaging to confirm multiple sclerosis on the basis of a single attack of neurological dysfunction may lead to over-diagnosis and over-treatment.

Case-Control Studies↗

PubMed2006

Mortality of HIV-1-infected patients in the first year of antiretroviral therapy: comparison between low-income and high-income countries.

BACKGROUND: Highly active antiretroviral therapy (HAART) is being scaled up in developing countries. We compared baseline characteristics and outcomes during the first year of HAART between HIV-1-infected patients in low-income and high-income settings. METHODS: 18 HAART programmes in Africa, Asia, and South America (low-income settings) and 12 HIV cohort studies from Europe and North America (high-income settings) provided data for 4810 and 22,217, respectively, treatment-naïve adult patients starting HAART. All patients from high-income settings and 2725 (57%) patients from low-income settings were actively followed-up and included in survival analyses. FINDINGS: Compared with high-income countries, patients starting HAART in low-income settings had lower CD4 cell counts (median 108 cells per muL vs 234 cells per muL), were more likely to be female (51%vs 25%), and more likely to start treatment with a non-nucleoside reverse transcriptase inhibitor (NNRTI) (70%vs 23%). At 6 months, the median number of CD4 cells gained (106 cells per muL vs 103 cells per muL) and the percentage of patients reaching HIV-1 RNA levels lower than 500 copies/mL (76%vs 77%) were similar. Mortality was higher in low-income settings (124 deaths during 2236 person-years of follow-up) than in high-income settings (414 deaths during 20,532 person-years). The adjusted hazard ratio (HR) of mortality comparing low-income with high-income settings fell from 4.3 (95% CI 1.6-11.8) during the first month to 1.5 (0.7-3.0) during months 7-12. The provision of treatment free of charge in low-income settings was associated with lower mortality (adjusted HR 0.23; 95% CI 0.08-0.61). INTERPRETATION: Patients starting HAART in resource-poor settings have increased mortality rates in the first months on therapy, compared with those in developed countries. Timely diagnosis and assessment of treatment eligibility, coupled with free provision of HAART, might reduce this excess mortality.

Adolescent↗

PubMed2006

Using bivariate models to understand between- and within-cluster regression coefficients, with application to twin data.

In the regression analysis of clustered data it is important to allow for the possibility of distinct between- and within-cluster exposure effects on the outcome measure, represented, respectively, by regression coefficients for the cluster mean and the deviation of the individual-level exposure value from this mean. In twin data, the within-pair regression effect represents association conditional on exposures shared within pairs, including any common genetic or environmental influences on the outcome measure. It has therefore been proposed that a comparison of the within-pair regression effects between monozygous (MZ) and dizygous (DZ) twins can be used to examine whether the association between exposure and outcome has a genetic origin. We address this issue by proposing a bivariate model for exposure and outcome measurements in twin-pair data. The between- and within-pair regression coefficients are shown to be weighted averages of ratios of the exposure and outcome variances and covariances, from which it is straightforward to determine the conditions under which the within-pair regression effect in MZ pairs will be different from that in DZ pairs. In particular, we show that a correlation structure in twin pairs for exposure and outcome that appears to be due to genetic factors will not necessarily be reflected in distinct MZ and DZ values for the within-pair regression coefficients. We illustrate these results in a study of female twin pairs from Australia and North America relating mammographic breast density to weight and body mass index.

Australia↗

PubMed2006

The geography of despair among 15-44-year-old men in England and Wales: putting suicide on the map.

OBJECTIVE: To investigate the spatial patterning and possible contributors to the geographical distribution of suicide among 15-44- year-old men. DESIGN: Small-area analysis and mapping of geo-coded 1988-94 suicide mortality data and 1991 census data using random-effects smoothing. SETTING: 9265 electoral wards in England and Wales (mean population of men aged 15-44- years: about 1220). MAIN RESULTS: Two main patterns emerged: (a) in all of the 10 most densely populated cities studied, suicide showed a "bull's-eye" pattern with rates highest in the inner-city areas and, in some cases, low rates in the peripheries, and (b) suicide rates were high in coastal areas, particularly those in more remote regions. Possible indicators of social fragmentation, such as the proportion of single-person households in an area, were most strongly and consistently associated with rates of suicide in both urban and rural areas. Levels of unemployment and long-term illness accounted for some of the coastal patterning. Although characteristics of areas accounted for more than half of the observed variability, substantial between-area variability in rates remained unexplained. CONCLUSIONS: The area characteristics investigated here did not fully account for the higher suicide rates observed in the most rural or remote areas. Alongside social and economic aspects, rural life itself may have an independent effect on the risk of suicide. A greater understanding of local geographies of suicide, and particularly the possible interactions between characteristics of people and their environments, might assist the design of prevention strategies that target those areas (and their characteristics) where risk is concentrated.

Adolescent↗

PubMed2006

Opportunistic and systematic screening for chlamydia: a study of consultations by young adults in general practice.

BACKGROUND: Opportunistic screening for genital chlamydia infection is being introduced in England, but evidence for the effectiveness of this approach is lacking. There are insufficient data about young peoples' use of primary care services to determine the potential coverage of opportunistic screening in comparison with a systematic population-based approach. AIM: To estimate use of primary care services by young men and women; to compare potential coverage of opportunistic chlamydia screening with a systematic postal approach. DESIGN OF STUDY: Population based cross-sectional study. SETTING: Twenty-seven general practices around Bristol and Birmingham. METHOD: A random sample of patients aged 16-24 years were posted a chlamydia screening pack. We collected details of face-to-face consultations from general practice records. Survival and person-time methods were used to estimate the cumulative probability of attending general practice in 1 year and the coverage achieved by opportunistic and systematic postal chlamydia screening. RESULTS: Of 12 973 eligible patients, an estimated 60.4% (95% confidence interval [CI] = 58.3 to 62.5%) of men and 75.3% (73.7 to 76.9%) of women aged 16-24 years attended their practice at least once in a 1-year period. During this period, an estimated 21.3% of patients would not attend their general practice but would be reached by postal screening, 9.2% would not receive a postal invitation but would attend their practice, and 11.8% would be missed by both methods. CONCLUSIONS: Opportunistic and population-based approaches to chlamydia screening would both fail to contact a substantial minority of the target group, if used alone. A pragmatic approach combining both strategies might achieve higher coverage.

Adolescent↗

PubMed2005

Partner notification of chlamydia infection in primary care: randomised controlled trial and analysis of resource use.

OBJECTIVE: To evaluate the effectiveness of a practice nurse led strategy to improve the notification and treatment of partners of people with chlamydia infection. DESIGN: Randomised controlled trial. SETTING: 27 general practices in the Bristol and Birmingham areas. PARTICIPANTS: 140 men and women with chlamydia (index cases) diagnosed by screening of a home collected urine sample or vulval swab specimen. INTERVENTIONS: Partner notification at the general practice immediately after diagnosis by trained practice nurses, with telephone follow up by a health adviser; or referral to a specialist health adviser at a genitourinary medicine clinic. MAIN OUTCOME MEASURES: Primary outcome was the proportion of index cases with at least one treated sexual partner. Specified secondary outcomes included the number of sexual contacts elicited during a sexual history, positive test result for chlamydia six weeks after treatment, and the cost of each strategy in 2003 sterling prices. RESULTS: 65.3% (47/72) of participants receiving practice nurse led partner notification had at least one partner treated compared with 52.9% (39/68) of those referred to a genitourinary medicine clinic (risk difference 12.4%, 95% confidence interval -1.8% to 26.5%). Of 68 participants referred to the clinic, 21 (31%) did not attend. The costs per index case were 32.55 pounds sterling for the practice nurse led strategy and 32.62 pounds sterling for the specialist referral strategy. CONCLUSION: Practice based partner notification by trained nurses with telephone follow up by health advisers is at least as effective as referral to a specialist health adviser at a genitourinary medicine clinic, and costs the same. Trial registration Clinical trials: NCT00112255.

Chlamydia Infections↗

PubMed2005

Incidence of Tuberculosis among HIV-infected patients receiving highly active antiretroviral therapy in Europe and North America.

BACKGROUND: We obtained estimates of the incidence of tuberculosis (TB) among patients receiving HAART and identified determinants of the incidence. METHODS: We analyzed the incidence of TB during the first 3 years after initiation of HAART among 17,142 treatment-naive, AIDS-free persons starting HAART who were enrolled in 12 cohorts from Europe and North America. We used univariable and multivariable Poisson regression models to identify factors associated with the incidence. RESULTS: During the first 3 years (36,906 person-years), 173 patients developed TB (incidence, 4.69 cases per 1000 person-years). In multivariable analysis, the incidence rate was lower for men who have sex with men, compared with injection drug users (relative rate, 2.46; 95% confidence interval [CI], 1.51-4.01), heterosexuals (relative rate, 2.42; 95% CI, 1.64-3.59), those with other suspected modes of transmission (relative rate, 1.66; 95% CI, 0.91-3.06), and those with a higher CD4+ count at the time of HAART initiation (relative rate per log2 cells/microL, 0.87; 95% CI, 0.84-0.91). During 28,846 person-years of follow-up after the first 6 months of HAART, 88 patients developed TB (incidence, 3.1 cases per 1000 person-years of follow-up). In multivariable analyses, a low baseline CD4+ count (relative rate per log2 cells/microL, 0.89; 95% CI, 0.83-0.96), 6-month CD4+ count (relative rate per log2 cells/microL, 0.90; 95% CI, 0.81-0.99), and a 6-month HIV RNA level >400 copies/mL (relative rate, 2.21; 95% CI, 1.33-3.67) were significantly associated with the risk of acquiring TB after 6 months of HAART. CONCLUSION: The level of immunodeficiency at which HAART is initiated and the response to HAART are important determinants of the risk of TB. However, this risk remains appreciable even among those with a good response to HAART, suggesting that other interventions may be needed to control the TB epidemic in the HIV-infected population.

Adult↗

PubMed2005

Stent-related ureteric obstruction in paediatric renal transplantation.

The rates of ureteric obstruction and complications for use of externally draining uretero-vesico-cutaneous (external) stents (Group 1: n=39) and the use of internal uretero-vesical (double-J) stents (Group 2: n=16), in 55 of 64 consecutive paediatric renal-transplant recipients, performed at our institution between January 1996 and December 2003, have been compared. Serum creatinine levels pre and post-operatively and pre and post-stent removal were recorded. The diagnosis of ureteric obstruction was based on an increase in serum creatinine of >or=20%, in conjunction with ultrasound evidence of hydronephrosis or hydroureter, where other causes of renal dysfunction were excluded. Ureteric obstruction occurred in 13 of the 39 patients (33.3%) in Group 1, compared with only one case of ureteric obstruction in the 16 patients (6.25%) in Group 2 (OR=7.5, 95% CI=0.8-70, P=0.038). There was no evidence of a difference in the number of urinary tract infections (9/39 in Group 1, 6/16 in Group 2, OR=0.5, 95% CI=0.14 to 1.8, P=0.275) or the mean length of hospital stay (10.9 days in Group 1, 10.1 days in Group 2, 95% CI=-2.3 to 4 days, P=0.565) between the two groups. Glomerular filtration rate (GFR) improved in the week after stent removal in Group 2, but deteriorated in Group 1 (P=0.07). This non-randomised comparison of stent types supports the use of prophylactic double-J stents in paediatric renal transplantation- in terms of decreased ureteric complications and improved renal function post-stent removal.

Adolescent↗