bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relevance of Sample Size Determination in Medical Research
Authors: Sathian Brijesh , Sreedharan Jayadevan , Baboo Suresh N , Sharan Krishna , Abhilash E S , Rajesh E 
Published: December 2010

Sample size determination is one of the central tenets of medical research. If the sample size is inadequate, then the study will fail to detect a real difference between the effects of two clinical approaches. On the contrary, if the sample size is larger than what is needed, the study will become cumbersome and ethically prohibitive. Apart from this, the study will become expensive, time consuming and will have no added advantages. A study which needs a large sample size to prove any significant difference in two treatments must ensure the appropriate sample size. It is better to terminate such a study when the required sample size cannot be attained so that the funds and manpower can be conserved. When dealing with multiple sub-groups in a population the sample size should be increased the adequate level for each sub-group. To ensure the reliability of final comparison of the result, the significant level and power must be fixed before the sample size determination. Sample size determination is very important and always a difficult process to handle. It requires the collaboration of a specialist who has good scientific knowledge in the art and practice of medical statistics. A few suggestions are made in this paper regarding the methods to determine an optimum sample size in descriptive and analytical studies.Key Words: Sample size; Power analysis; Medical researchDOI: 10.3126/nje.v1i1.4100Nepal Journal of Epidemiology 2010;1 (1):4-10
Diabetes mellitus as a Potential Risk Factor for Renal Disease among Nepalese: A Hospital Based Case Control Study
Authors: Mittal Ankush , Sathian Brijesh , Kumar Arun , Chandrasekharan Nishida , Sunka Aditya 
Published: December 2010

BackgroundDiabetes mellitus is a well recognized public health concern and projections of its future effect are alarming. It is one of the leading causes of end stage renal disease in both developed and emerging nations. The objective of the present study was to assess the progressive deterioration of renal function in Diabetes mellitus among Nepalese.Materials and Methods It was a hospital based case control study carried out in the Department of Biochemistry of Manipal Teaching Hospital, Pokhara, Nepal between 1st January 2010 and 31st August 2010. The variables collected were age, gender, random blood glucose, serum urea and creatinine levels of the patients. ResultsOut of 440 patients, there was a slight predominance of males (54.1%) as compared to females (45.8%). Patients in between 41-100 years were 2.8 times more at risk of developing kidney disease as compared to age group (0-40 years)(Odds Ratio=2.8, p=0.0001). Diabetic patients were twice at risk of developing kidney disease than non diabetics (Odds Ratio=1.97, p=0.001). There was a significant increase in mean values of serum creatinine (CI 4.3 to 4.8) and urea (CI 118.55 to 153.50) in kidney disease patients with Diabetes mellitus. In non diabetic kidney disease patients, mean values of serum creatinine (CI 3.29 to 3.70) and urea (CI 98.88 to 116.92) were also moderately raised as compared to controls.ConclusionDiabetic renal lesions are not only preventable but also reversible. In summary, glycemic control significantly influences the rate of progression from microalbuminuria to proteinuria and from overt nephropathy to end stage renal disease. The best modality of treatment includes strict control over blood glucose levels and its evaluation at frequent intervals.Key Words: Diabetic Mellitus; Kidney Disease; Case Control Study; NepalDOI: 10.3126/nje.v1i1.4108Nepal Journal of Epidemiology 2010;1 (1):22-25
Epidemiologic Analysis of Gastric Carcinoma in the Western Region of Nepal
Authors: Ghosh Arnab , Sathian Brijesh , Ghartimagar Dilasma , Narasimhan Raghavan , Talwar Om Prakash 
Published: December 2010

BackgroundGastric cancer is among the most common malignancies in Asia, comprising 74% of all global cases. Identifying the environmental risk factors may possibly shed more light on effective treatment and the prevention of this disease. The aim of our study is to document different histologic types of gastric cancer as per age, sex and ethnic groups in the patients in Nepal, to know the frequency of different gross and microscopic subtypes (according to Lauren's classification) of tumor and to find out the association of H. pylori and other major risk factors with gastric cancer.Materials and Methods The present study is a hospital based retrospective study done in the Department of Pathology, Manipal Teaching Hospital, Pokhara, Nepal, from Jan 1999 to July 2010. All the endoscopic biopsies and gastrectomy specimens from patients with diagnosed gastric carcinoma were reviewed and the clinical and other data were analyzed.ResultsIn this study period, a total of 1223 cases related to stomach were received in Department of Pathology. Considering the inclusion and exclusion criteria, a total of 397 cases - 315 cases of endoscopic biopsy and 82 cases of gastrectomy - were included in the study. In our study, the most affected age group and caste were 61-70 years ( 47.36%, CI 42.44% to 52.27%) and Gurungs (32%, CI 27.16% to 36.32%). The commonest gross and microscopic types were Borrmann's type IV (40%, CI 29.63% to 50.86%) and intestinal type (53%, CI 47.99% to 57.81%). Gastric antrum was the most affected site (70%, CI 65.26% to 74.29%). Among the cases with H pylori, antrum (62.5% CI 45.73% to 79.27%) was found to be the commonest site. Among all cases in Gurung, Chhetri and Brahmin communities, we retrieved data regarding risk factors in 93, 65 and 50 cases respectively. Significant relationship was found between the three risk factors studied and the ethnic groups. Smoked meat and alcohol were found to be associated with gastric carcinoma more in Gurungs and Chhetris than in Brahmins (p= 0.0001). On the contrary, cases among Brahmins are found to more associated with smoking than Gurungs and Chhetris (p= 0.0001).ConclusionGastric carcinoma is a common malignancy in this part of world. The most high risk group includes elderly males with history of alcoholism and smoked meat consumption in Gurung community and with history of smoking from Brahmin family. We advise that regular endoscopic surveillance should be done at least in high risk group for the early detection of cancer.Key Words: Gastric Carcinoma; Ethnicity; Risk Factors; Epidemiology; Helicobacter pylori; NepalDOI: 10.3126/nje.v1i1.4109Nepal Journal of Epidemiology 2010;1 (1):27-32
The Significance of Transaminases and Deritis Ratio for Predicting Alcoholic Liver Disease: A Hospital Based Comparative Study in Western Nepal
Authors: Mittal Ankush , Sathian Brijesh , Kumar Arun , Chandrasekharan Nishida , Yadav Shambhu Kumar 
Published: December 2010

BackgroundIn Nepal, alcoholic liver disease (ALD) is a major public health problem. In testing for biochemical abnormalities in ALD, Deritis ratio (AST/ALT) is more sensitive than other conventional parameters, at any stage of the disease. The aim of our study was to assess closely the significance of transaminases and deritis ratio and their predictive implications among the patients of alcoholic liver disease in Pokhara valley.Materials and Methods It was a hospital based retrospective study carried out from the data maintained in the Department of Biochemistry of the Manipal Teaching Hospital, Pokhara, Nepal between 1st January 2009 and 31st July 2010. The variables collected were age, gender, total protein, albumin, AST, ALT and AST/ALT ratio. Descriptive statistics and testing of hypothesis were used for the analysis. Data was analyzed using EPI INFO and SPSS 16 software.ResultsOf the four hundred forty-five patients, there was a slight preponderance of males (55.5%) towards ALD as compared to females (44.5%), projecting the percentage of ALD to around 28.8. Males were 2.3 times more at risk of developing alcoholic liver disease than females (Odds Ratio=2.3, p=0.0001). Patients over 40 years of age had 3.2 times greater propensity of developing alcoholic liver disease (Odds Ratio=3.2, p=0.0001). In ALD patients, mean value of AST (131.5 ± SD94.46 IU/L) was markedly increased in comparison to ALT (85.12 ± SD58.24 IU/L) leading to significantly higher AST/ALT ratio (1.59 ± SD0.58). In cases, mean value of Deritis ratio was 1.59 with CI (1.49, 1.69) which was significantly increased as compared to the ratio in controls which was 1.04 with CI (1.02, 1.06) (p=0.001). 96.9% of patients with alcoholic liver disease had an AST:ALT ratio of >1.0 with CI (93.9%,99.9%). The mean value of each variable in cases was significantly elevated as compared to controls (p=0.001).ConclusionEthanol consumption leads to a spectrum of liver diseases, the importance of which is magnified by its widespread use. Laboratory tests play an important role in this endeavor. Equally important is the fact that once complications of alcoholism are identified, it is imperative to be able to accurately determine their magnitude. Therefore, the estimation of deritis ratio is useful for the rational understanding of the extent of damage in alcoholic liver disease.Key Words: Transaminase; Deritis ratio; Alcohol Liver Disease; NepalDOI: 10.3126/nje.v1i1.4110Nepal Journal of Epidemiology 2010;1 (1): 33-37
Statistical Modelling Technique in Forecasting of Palliative Oncotherapy Load in Hospitals
Authors: Sathian Brijesh , Sreedharan Jayadevan , Sharan Krishna , Baboo Suresh N , Chawla Rachit , Chandrasekharan Nishida , Rajesh E , Shah Ravi Kumar , Baniya Ramkaji , Dixit Shyam B 
Published: December 2010

BackgroundAn increase in cancer incidence in developing countries is expected due to the possible decline of mortality from infectious diseases, improved healthcare, population growth and increasing life expectancy. It can therefore be anticipated that the number of cancer patients requiring palliative treatment will also rise in Nepal, creating a discrepancy between the requirement and delivery of health care. Estimation of trends is very essential for the planning of future requirements in any such programme.Method This retrospective study analysed the records from the Radiotherapy Department at Manipal Teaching Hospital, Pokhara, Nepal to calculate the number of cancer patients who received palliative treatment with radiotherapy between September 2000 and December 2008. Descriptive statistics was used for the analysis and subsequently, statistical modelling techniques were applied for forecasting of future trends.ResultsOf 1001 cancer cases, 363 patients received radiotherapy with palliative intent during the study period. Excluding the constant term from the equation, the Logarithmic model was the best fitted, with R2 = 0.727, p = 0.002 for the forecasting of cancer patients receiving palliative treatment. Using this model, the number of cancer cases receiving palliative radiotherapy at the hospital in the year 2015 was estimated to be 68. Thus, the number of patients requiring radiotherapy with palliative intent shows a pattern of increasing trend over the coming years.ConclusionThe data analysed in the present study indicates an increasing future trend of patients requiring palliative therapy at the centre. In the future, a discrepancy may arise between the requirement and capacity of care available to these patients. Government and healthcare agencies of Nepal must ready themselves to promote better strategies for adequate provision to the cancer patients receiving palliative treatment in the coming years.Key WordsStatistical Modelling; Palliative Oncotherapy; ForecastingDOI: 10.3126/nje.v1i1.4111Nepal Journal of Epidemiology 2010;1 (1):38-43
Scoliosis and Chiari malformation Type I in children
Authors: Krieger Mark D. , Falkinstein Yuri , Bowen Ira E. , Tolo Vernon T. , McComb J. Gordon 
Published: December 2010

Object
The identification of Chiari malformations Type I (CM-Is) has increased in recent years, commonly during MR imaging for evaluation of a possible cause of scoliosis. The treatment of this abnormality remains controversial, and the expected success of treatment is unclear. The goal of the present study is to evaluate the effects of a craniotomy for CM-I decompression on scoliosis in children and adolescents.

Methods
The authors conducted a 10-year retrospective review of pediatric patients who were found to have a CM-I during evaluation for scoliosis. Seventy-nine patients were identified, ranging in age from 6 months to 18 years (median 12 years). There were 42 girls (54%) and 37 boys (46%). All were noted on MR imaging to have hydrosyringomyelia of the spinal cord. Forty-nine patients had curvatures less than 20° prior to treatment. The other 30 patients had curves ranging from 25° to 80° and underwent orthopedic follow-up and treatment. None of these patients were referred for specific neurological complaints, but 12 (16%) had neurological signs on physical examination. All were treated with a craniocervical decompression in a standard fashion. Follow-up ranged from 6 to 93 months with a median of 35 months. Magnetic resonance images obtained at 6 months postoperatively and serial standing anteroposterior spine radiographs were used to evaluate outcomes.

Results
On the MR images obtained 6 months postoperatively, 70 patients (89%) had a significant reduction in the syrinx with an associated ascent of the cerebellar tonsils. Persistent large syringes were treated with reoperation in 6 patients, and shunts were inserted for hydrocephalus in 2 patients. None of the 49 patients with curves less than 20° had progression of their curvature postoperatively. Of the 30 patients with curves greater than 25°, 9 had no change in the scoliosis or had a reduction in curve magnitude after Chiari decompression. This group required no further therapy and was effectively treated by Chiari decompression alone. Twenty-one patients required further scoliosis treatment after Chiari decompression; 12 required orthotic treatment, 11 received spinal instrumentation and fusion surgery, and 2 received orthoses followed by fusion and instrumentation. The severity of the curvature beyond 20° did not predict the need for spinal surgery.

Conclusions
This large series reports on the efficacy of treatment for scoliosis associated with a CM-I and syrinx in children. A CM-I decompression alone was adequate treatment for mild scoliosis of less than 20°. Patients with scoliosis greater than 20° required bracing and/or spinal fusion surgery 70% of the time in addition to the CM-I decompression.
Morbidity and mortality associated with spinal surgery in children: a review of the Scoliosis Research Society morbidity and mortality database
Authors: Fu Kai-Ming G. , Smith Justin S. , Polly David W. , Ames Christopher P. , Berven Sigurd H. , Perra Joseph H. , Glassman Steven D. , McCarthy Richard E. , Knapp D. Raymond , Shaffrey Christopher I. , _ _ 
Published: December 2010

Object
Currently, few studies regarding morbidity and mortality associated with operative treatment of spinal disorders in children are available to guide the surgeon. This study provides more detailed morbidity and mortality data with an analysis of 23,918 pediatric cases reported in the multicenter, multisurgeon Scoliosis Research Society morbidity and mortality database.

Methods
The Scoliosis Research Society morbidity and mortality database was queried for the years from 2004 to 2007. The inclusion criterion was age 18 years or younger. Cases were categorized by operation type and diagnosis. Details on the surgical approach, use of neurophysiological monitoring, and type of instrumentation were recorded. Major perioperative complications and deaths were evaluated. Statistical analysis was performed with chi-square testing, with a p value < 0.05 considered significant.

Results
A total of 23,918 patients were included. The mean age was 13 ± 3.6 years (± SD). Spinal pathology included the following: scoliosis (in 19,642 patients), kyphosis (in 1455), spondylolisthesis (in 748), trauma (in 478), and other (in 1595 patients). The overall complication rate was 8.5%. Major complications included wound infections (2.7%), new neurological deficits (1.4%), implant-related complications (1.6%), and hematomas (0.4%). The most common medical complications were respiratory related (0.9%). Morbidity rates differed based on pathology, with patients undergoing treatment for kyphosis and spondylolisthesis having higher overall rates of morbidity (14.7% and 9.6%, respectively). Patients undergoing revision procedures (2034) or corrective osteotomies (2787) were more likely to suffer a complication or new neurological deficit. The majority of these deficits improved at least partially. Thirty-one deaths were reported for an overall rate of 1.3 per 1000. Respiratory complications were the most common cause of mortality (13 cases). Twenty-six of the deaths occurred in children undergoing scoliosis correction.

Conclusions
Spinal surgery in children is associated with a range of complications depending on the type of operation. Mortality rates for all indications and operations were low. Patients undergoing more aggressive corrective procedures for deformity are more likely to suffer complications and new neurological deficits.
Small-ventricle neuroendoscopy for pediatric brain tumor management
Authors: Naftel Robert P. , Shannon Chevis N. , Reed Gavin T. , Martin Richard , Blount Jeffrey P. , Tubbs R. Shane , Wellons John C. 
Published: December 2010

Object
The use of intraventricular endoscopy to achieve diagnosis or to resect accessible intraventricular or paraventricular tumors has been described in the literature in both adults and children. Traditionally, these techniques have not been used in patients with small ventricles due to the perceived risk of greater morbidity. The authors review their experience with the effectiveness and safety of endoscopic brain tumor management in children with small ventricles.

Methods
Between July 2002 and December 2009, 24 children with endoscopically managed brain tumors were identified. Radiological images were reviewed by a radiologist blinded to study goals and clinical setting. Patients were categorized into small-ventricle and ventriculomegaly groups based on frontal and occipital horn ratio. Surgical success was defined a priori and analyzed between groups. Trends were identified in selected subgroups, including complications related to pathological diagnosis and surgeon experience.

Results
Six children had small ventricles and 18 had ventriculomegaly. The ability to accomplish surgical goals was statistically equivalent in children with small ventricles and those with ventriculomegaly (83% vs 89%, respectively, p = 1.00). There were no complications in the small-ventricle cohort, but in the ventriculomegaly cohort there were 2 cases of postoperative hemorrhages and 1 case of infection. All hemorrhagic complications occurred in patients with high-grade tumor histopathological type and were early in the surgeon's endoscopic career.

Conclusions
Based on our experience, endoscopy should not be withheld in children with intraventricular tumors and small ventricles. Complications appear to be more dependent on tumor histopathological type and surgeon experience than ventricular size.
The effectiveness of ventriculocystocisternostomy for suprasellar arachnoid cysts
Authors: Maher Cormac O. , Goumnerova Liliana 
Published: December 2010

Object
The aim of this study was to report the long-term outcomes of patients receiving endoscopic ventriculocystocisternostomy (VCC) for suprasellar arachnoid cysts (SACs), and to analyze all published reports on outcomes of ventriculocystostomy (VC) versus VCC to compare the effectiveness of the 2 techniques.

Methods
Eleven consecutive patients with previously untreated SACs were surgically treated using endoscopic VCC. Another 2 patients were treated with VCC following ventriculoperitoneal shunt placement. Clinical imaging data were recorded. An analysis was performed of all published patient outcomes following endoscopic VC or VCC for an SAC.

Results
Developmental delay and progressive macrocephaly were the most common preoperative symptoms. At a mean clinical follow-up interval of 63 months, 10 of 11 patients undergoing primary VCC did not require reoperation. An analysis of the literature suggests that VCC may be more effective than VC. Of the 44 reported patients that underwent VC as a first treatment, 7 (16%) required reoperation, and 7 (8%) of 86 patients who underwent VCC as a first treatment required reoperation. When VC or VCC was performed following a prior surgical procedure, 4 of 11 patients undergoing VC had a treatment failure requiring reoperation. In contrast, only 2 of the 17 reported cases of VCC following a prior procedure required further treatment. The difference in reoperation rates following either primary or secondary VC was significantly higher than following primary or secondary VCC (p = 0.04).

Conclusions
The authors conclude that VCC is an effective and durable treatment for symptomatic SACs in most cases.
Idiopathic syrinx in the pediatric population: a combined center experience
Authors: Magge Suresh N. , Smyth Matthew D. , Governale Lance S. , Goumnerova Liliana , Madsen Joseph , Munro Becca , Nalbach Stephen V. , Proctor Mark R. , Scott R. Michael , Smith Edward R. 
Published: December 2010

Object
Discovery of a syrinx in a child, without a readily identifiable proximate cause such as a Chiari malformation, tumor, or site of tethering, is often a cause of concern for families and a source of consternation for clinicians. There is a paucity of data describing the natural history of an idiopathic syrinx in the pediatric population. The authors present the combined data of 2 major pediatric neurosurgical centers to describe their experience with this condition.

Methods
Data were collected at Children's Hospital Boston and St. Louis Children's Hospital according to institutional review board–approved protocols and captured visits over a 2.5-year interval (October 2006–March 2009), with records reviewed if the patient had a preexisting diagnosis of syrinx. Patients were identified by ICD-9 codes derived from departmental databases. All pediatric patients (age < 19 years) in whom idiopathic syrinx had been diagnosed, as defined by MR imaging findings (dilated central canal in the spinal cord of ≥ 1 mm in axial dimension and extending over at least 2 vertebral levels), were included.

Results
Forty-eight patients met the criteria for idiopathic syrinx during this period, and in 32 of them detailed follow-up imaging was available. Discovery of a syrinx was incidental in 6 patients, whereas the others were referred for imaging because of the presence of pain, neurological symptoms, scoliosis, or skin markings. The average age at the first MR imaging session was 9.7 years, with a mean syrinx size of 4 mm (range 1.2–9.4 mm). The majority (52%) of patients had a thoracic syrinx, with the average lesion spanning 7.1 vertebral levels. The average follow-up was 23.8 months (range 2–64 months), and subgroups of patients with < 3 years and ≥ 3 years of follow-up were independently reviewed. Overall, symptoms improved in 34% and worsened in 9%; 57% of the patients remained asymptomatic or stable. Radiographically (in the subgroup of 32 patients with detailed follow-up imaging), syrinx size decreased in 25% of patients, increased in 12.5%, and remained unchanged in 62.5%, with no apparent correlation between change in syrinx size and clinical symptoms.

Conclusions
Clinically, children with an idiopathic syrinx remained asymptomatic, stable, or improved in 91% of cases. The majority of syringes (87.5%) remained stable or shrank over time, with no apparent correlation between changes in size and changes in symptoms. Although longer follow-up is needed, these data suggest that the natural history of an idiopathic syrinx in children is benign, and that repeated imaging may not be necessary.