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Biomedical subjects

H Ortiz

Publications and source records attributed to H Ortiz.

At least 19 recordsLinked to original sources

Global and regional volume changes in the brains of patients with phenylketonuria.

BACKGROUND: Although phenylketonuria is a treatable disease, patients with late or nonoptimal phenylalanine-restricted diet may experience brain damage. The authors used tridimensional MRI and a voxelwise analysis method to investigate possible volume changes in the brain parenchyma of patients with phenylketonuria. METHODS: The authors assessed 27 treated patients (mean age +/- SD, 20 +/- 7 years) and 27 matched control subjects. Global tissue volumes were compared, and statistical parametric maps of between-group regional volume differences were obtained for gray and white matter. Anatomic data were correlated with relevant clinical and biochemical variables. RESULTS: Patients with phenylketonuria showed smaller gray matter volumes that were associated with lower IQ and older age at diagnosis. Voxel-based maps revealed that significant gray matter volume reduction occurred in motor and premotor cortex and thalamus. A relative increase in gray matter volume was observed in the ventral part of the striatum. The authors found no group differences for global white matter measurements. Higher recent phenylalanine levels, however, were associated with larger global white matter volume in early-treated patients. Voxel-based maps showed a relative volume reduction in periventricular white matter and a relative increase in the region of the internal capsule, extending to the adjacent thalamus and striatum. CONCLUSIONS: Treated patients may show significant gray and white matter volume changes related to the duration and strict observation of dietary treatment. Further studies are needed to investigate whether the presence of neurologic symptoms may be explained by specific anatomic alterations.

Adolescent↗

Myelination of language-related areas in the developing brain.

BACKGROUND: The rapid development of language abilities in early childhood coincides with a similarly accelerated progression in brain maturation. OBJECTIVE: To quantitate myelination in the lateral part of the verbal left hemisphere from birth to 3 years in the living human brain. METHODS: One hundred children (mean age 16.6 months) were examined using three-dimensional MRI, and a subgroup of 40 children were also evaluated behaviorally. The volume of myelinated white matter was measured in language-related temporal and frontal regions and in the central sensorimotor region. A method was developed to compose a movie sequence for all the myelination process using volumetric data. RESULTS: A plot of age against relative volume of myelinated white matter graphically detailed the myelination progress in the lateral brain. The changes started in sensorimotor white matter and the Heschl gyrus and ultimately extended to the language-related areas. Both comprehension and production regions showed a very similar myelination course, suggesting simultaneous maturation of the temporofrontal language network. The movie sequence of white matter images dynamically displayed the anatomic details of myelin deposition in this part of the brain. The analysis of language performance showed acceleration in children's vocabulary after 18 months, once a rapid myelination phase was attained in the language brain. CONCLUSIONS: This volumetric study may contribute to further characterize the early stages of brain maturation by showing the fine progression of myelin deposition in the language domains and illustrating its relationship to children's vocabulary acquisition.

Brain↗

Gastroesophageal reflux: prevalence of psychopathological disorders and quality of life implications.

There is evidence in the literature that psychosocial aspects affect the symptoms and results of surgery for gastroesophageal reflux. The purpose of this study was to estimate the prevalence of psychopathological disorders measured using the General Health Questionnaire (GHQ-28) in a sample of patients with gastroesophageal reflux, and to assess the influence of such disorders on their quality of life. A prospective study was conducted in 74 consecutive patients before gastroesophageal reflux surgery; patients answered the GHQ-28, the health questionnaire SF-36, and the Gastrointestinal Quality of Life Index (GIQLI). The convergent validity of the GHQ-28 questionnaire as compared to the other two questionnaires and preoperative quality of life was tested. A pathological result of the GHQ-28 questionnaire was found in 38.3% of patients. A correlation was seen between the results of the GHQ-28 questionnaire and all categories of the SF-36 and GIQLI questionnaires. Patients with pathological results in the GHQ-28 questionnaire had poorer results in all dimensions of the SF-36 and GIQLI quality of life questionnaires as compared to patients with a normal result in the GHQ-28 questionnaire. In conclusion, 38.3% of patients with gastroesophageal reflux showed psychopathological disorders when administered the GHQ-28 questionnaire. These patients also had poorer results in quality of life studies.

Adult↗

Quality of life assessment in patients with chronic anal fissure after lateral internal sphincterotomy.

BACKGROUND: The aim of this study was to compare quality of life of patients with chronic anal fissure before and after open lateral internal sphincterotomy. METHODS: A prospective study was undertaken of 108 consecutive patients with a history of chronic anal fissure who underwent lateral internal sphincterotomy. Quality of life was measured before and 6 months after operation with the Short-Form 36 (SF-36) Health Survey. RESULTS: Quality of life improved significantly in six of the eight scales of the SF-36 questionnaire: physical functioning, role physical, bodily pain, energy, social functioning and mental health. There were no significant differences between the 70 patients who had no change in continence after operation and the 38 patients with continence disturbances after sphincterotomy. However, there were significant improvements in four scales in patients without changes in continence compared with improvements in only two scales in those with continence disturbances. CONCLUSION: Patients with chronic anal fissure showed an improvement in quality of life 6 months after internal lateral sphincterotomy. Patients with postoperative continence disturbances showed improvement in fewer scales of the SF-36 questionnaire than those without changes in continence.

Adult↗

Prospective study of artificial anal sphincter and dynamic graciloplasty for severe anal incontinence.

BACKGROUND AND AIMS: Dynamic graciloplasty and artificial anal sphincter are two options for refractory incontinence, the efficacy of which was compared in a prospective study. PATIENTS AND METHODS: Between November 1966 and June 1998, 16 patients were operated on (artificial anal sphincter 8, dynamic graciloplasty 8). Four consecutive operations with each technique were performed by two colorectal surgeons (one initiated the study with the neosphincter and the other with dynamic graciloplasty). Two independent observers assessed postoperative results at 4-month intervals. Patients were followed up to January 2001, with a median (interquartile range) of 44 (13) months and 39 (15) months for the nesophincter and the dynamic graciloplasty, respectively. RESULTS: Fourteen patients had complications. In the immediate postoperative period; there were eight cases of wound healing-related problems (four in the graciloplasty group). Perineal infection occurred in one patient in the graciloplasty group. At follow-up there were 11 complications (6 in the neosphincter group). Four patients undergoing neosphincter implantation had erosion or pain at the cuff site and had the implant removed (a new device was reimplanted in one). Four patients undergoing dynamic graciloplasty had the stimulator removed. Postoperatively the neosphincter was associated with a significantly lower score on the continence grading scale of the Cleveland Clinic Florida than graciloplasty. CONCLUSION: The artificial anal sphincter is a more convenient technique than dynamic graciloplasty for institutions treating small number of patients. However, technical failures and complications during follow-up that require reoperation are very high in both types of treatments.

Adolescent↗

Complications and functional outcome following artificial anal sphincter implantation.

BACKGROUND: The postoperative complications and functional outcome following 24 consecutive implantations of an artificial anal sphincter were assessed prospectively. METHODS: A total of 24 artificial anal sphincters (Acticon Neosphincter) were implanted in 22 patients (mean age 47 years). The mean follow-up period was 28 (range 6-48) months. Results were assessed prospectively by two independent observers at 4-month intervals. The cumulative probability of artificial anal sphincter removal was analysed by the Kaplan-Meier method. RESULTS: Five patients were free of complications. During the postoperative period, complications occurred in nine patients, two of whom required reoperation. During follow-up, complications developed in ten patients, nine of whom were reoperated. Definitive device explantation was necessary in seven patients. The cumulative probability of device explantation was 44 per cent at 48 months. The 15 patients with functioning implants were followed up for a mean of 26 (range 7-48) months. Continence grading improved from a mean of 18 (range 14-20) in the preoperative period to 4 (range 0-14) after operation (P < 0.001). Resting anal canal pressure in patients with a functioning implant increased from a mean of 35 (range 8-87) mmHg before operation to 54 (range 34-70) mmHg after implantation (P < 0.01). CONCLUSION: An artificial anal sphincter is a useful alternative for refractory faecal incontinence but the incidence of late postoperative complications is high.

Adolescent↗

Randomized clinical trial of stapled haemorrhoidopexy versus conventional diathermy haemorrhoidectomy.

BACKGROUND: The aim of this study was to compare the results of stapled haemorrhoidopexy (commonly called stapled haemorrhoidectomy) with those of conventional diathermy haemorrhoidectomy. METHODS: Fifty-five patients with symptomatic third- and fourth-degree haemorrhoids were randomized to either stapled haemorrhoidopexy (n = 27) or conventional diathermy haemorrhoid ectomy (n = 28). Operating time, postoperative pain, time to return to work, postoperative complications and effectiveness of haemorrhoidal symptom control were recorded. The mean follow-up was 15.9 months in the stapled haemorrhoidopexy group and 15.2 months in the conventional haemorrhoidectomy group. RESULTS: Mean pain intensity was significantly less in the stapled group (P = 0.001). There were no significant differences in the total number of complications, the length of absence from work or control of symptoms. Seven patients in the stapled group re-presented with prolapse compared with none in the conventional haemorrhoidectomy group (P = 0.004). This difference was also observed in the subset of patients with fourth-degree haemorrhoids (P = 0.003). CONCLUSION: The stapled operation was significantly less painful than conventional haemorrhoidectomy. However, the rate of recurrent prolapse was higher after stapled haemorrhoidopexy than after conventional diathermy haemorrhoidectomy.

Diathermy↗

Accuracy of hydrogen peroxide-enhanced ultrasound in the identification of internal openings of anal fistulas.

OBJECTIVE: This prospective study was designed to assess the accuracy of hydrogen peroxide-enhanced ultrasound in the identification of internal openings of anal fistulas, with surgical findings as the golden standard. PATIENTS AND METHODS: A total of 143 consecutive patients (102 men; mean age, 45 years) with fistula-in-ano were assessed by hydrogen peroxide-enhanced ultrasound before surgery involving one radiologist. Ultrasound was performed using a B & K Diagnostic Ultrasound System trade mark with a 10-MHz rotating endoprobe. Hydrogen peroxide (3%) was infused into the fistula. All operations were perfomed by the same surgeon who was unaware of results of anal endosonography. RESULTS: In 128 (89.5%) patients, an internal opening was identified at surgery. Correct identification of an internal opening endosonographically was recorded in 80 (62.5%) patients. The internal opening was correctly identified by ultrasound in 32% (8/25) of patients with intersphincteric fistulas, in 77% (70/91) with transsphincteric fistulas, and in 17% (2/12) with suprasphincteric fistulas. CONCLUSION: The accuracy of hydrogen peroxide-enhanced anal endosonography for the identification of internal openings was still insufficient to justify pre-operative endosonography as a diagnostic method for routine use in patients with fistula-in-ano.

Journal Article↗

Motor vehicle crashes and abnormal driving behaviours in patients with dementia in Mendoza, Argentina.

Studies conducted in industrialized countries have shown that elderly demented subjects have increased risk of car accidents. However, there is no information about the effect of dementia on driving habits in non-industrialized countries. The number of motor vehicle crashes (MVC) and abnormal driving behaviours (ADB) (e.g. not recognizing traffic lights, driving in the middle of the road, etc.) were assessed with a semi-structured interview in 56 demented subjects and 31 elderly controls, all of whom were active drivers, at the Regional Registry of Dementia in Mendoza. Detailed neurological, psychiatric and neuropsychological examinations were also conducted on each subject. The presence of dementia and sex (male) predicted ADB, MVC and number of MVC (two or more). Among demented patients, ADB and MVC were associated with sex (male) and number of MVC was associated with sex (male) and Blessed Dementia Rating Scale for activities of daily living scores. Neither ADB, MCV, or number of MVC were associated with education level, or with cognitive or psychiatric measures. These findings showed that in developing countries, dementia has a significant contribution to MVC and ADB, as occurs in industrialized nations. Consequently, legislation to curb the risk of accidents caused by demented patients should be implemented. Furthermore, physicians must encourage demented patients (or their families) to discontinue driving, even those with mild dementia syndrome.

Accidents, Traffic↗

Anemia is associated with decreased survival and increased locoregional failure in patients with locally advanced head and neck carcinoma: a secondary analysis of RTOG 85-27.

PURPOSE: The purpose of the present study is to investigate the strength of association between anemia and overall survival, locoregional failure, and late radiation therapy (RT) complications in a large prospective study of patients with advanced head and neck cancer treated with conventional radiotherapy with or without a hypoxic cell sensitizer. METHODS AND MATERIALS: Between March 1988 and September 1991, 521 patients with Stage III or IV squamous cell carcinoma of the head and neck were entered into a randomized trial examining the addition of etanidazole (SR 2508) to conventional radiation therapy (RT) (66-74 Gy in 33-37 fractions, 5 days a week). Patients with hemoglobin (Hgb) levels measured and recorded prior to the second week of RT were included in this secondary analysis. Hemoglobin levels were stratified as normal (> or = 14.5 gm% for men, > or = 13 gm% for women) or anemic (< 14.5 gm% for men, < 13 gm% for women). Locoregional failure rates were calculated using the cumulative incidence approach. Overall survival was estimated according to the Kaplan-Meier method. Late RT toxicity was scored according to the RTOG morbidity scale. Differences in rates of overall survival, locoregional failure, and late complications were tested by the Cox proportional hazard model. RESULTS: Of 504 eligible patients, 451 had a Hgb level measured and recorded prior to the second week of RT. One hundred sixty-two patients (35.9%) were considered to have a normal Hgb level and 289 patients (64.1%) were considered to be anemic. The estimated survival rate is 35.7% at 5 years in patients with a normal Hgb, versus 21.7% in anemic patients (p = 0.0016). The estimated locoregional failure rate is 51.6% at 5 years in patients with a normal Hgb, versus 67.8% in anemic patients (p = 0.00028). The estimated rate of grade 3 or greater toxicity is 19.8% at 5 years in patients with a normal Hgb, versus 12.7% in anemic patients (p = 0.063). On multivariate analysis, several variables were found to be independent predictors of survival including: T stage, Karnofsky performance status, N stage, age, total radiation dose to the primary, and Hgb level. Independent predictors of locoregional control included T stage, Karnofsky performance status, N stage, radiation dose, and Hgb level. The only variables which predicted for the development of late RT complications were gender (p = 0.0109) and age (p = 0.0167). These findings were consistent regardless of whether Hgb level was considered a dichotomous or continuous variable. CONCLUSION: Low Hgb levels are associated with a statistically significant reduction in survival and an increase in locoregional failure in this large prospective study of patients with advanced head and neck cancer. Hgb level should be considered as a stratification variable in subsequent studies of head and neck cancer. Strategies to increase Hgb prior to RT in patients with head and neck cancer may lead to improved survival and loco-regional control.

Analysis of Variance↗

Regular production of infective sporozoites of Plasmodium falciparum and P. vivax in laboratory-bred Anopheles albimanus.

One of the major constraints for studies on the sporogonic cycle of the parasites causing human malaria, and on the protective efficacy of pre-erythrocytic vaccines, is the scarcity of laboratory-reared Anopheles mosquitoes as a source of infective sporozoites. The aim of the present study was to reproduce the life-cycles of Plasmodium falciparum and P. vivax in the laboratory and so develop the ability to produce infective sporozoites of these two species regularly under laboratory conditions. Colonized Anopheles albimanus, of Buenaventura and Tecojate strains, were infected by feeding either on Plasmodium-infected blood, from human patients or experimentally inoculated Aotus monkeys, or on gametocytes of the P. falciparum NF-54 isolate grown in vitro. The monkeys were infected with the blood stages of a Colombian P. vivax isolate and then, after recovery, with the Santa Lucia strain of P. falciparum from El Salvador. Although both of the mosquito strains used were successfully infected with both parasite species, the Buenaventura strain of mosquito was generally more susceptible to infection than the Tecojate strain, and particularly to infection with the parasites from the patients, who lived where this strain of mosquitoes was originally isolated. Monkeys injected intravenously with the P. vivax sporozoites produced in the mosquitoes developed patent sexual and asexual parasitaemias; the gametocytes that developed could then be used to infect mosquitoes, allowing the development of more sporozoites. However, experimental infections failed to establish after the P. falciparum sporozoites were used to inoculate monkeys. The ability to reproduce the complete life cycle of P. vivax in the laboratory, from human to mosquito and then to monkey, should greatly facilitate many studies on vivax malaria and on the efficacy of candidate malaria vaccines. The availability of the sporogonic cycles of P. falciparum from three different sources should also permit a variety of biological studies.

Animals↗

Is early postoperative feeding feasible in elective colon and rectal surgery?

UNLABELLED: In reports on earlier non-prospectively randomized trials the authors have claimed that early oral postoperative feeding is a unique benefit of laparoscopic surgery. On the other hand, some authors have suggested that early feeding could be tolerated by the majority of patients after elective open surgery. AIM: This prospective randomized study was undertaken to assess the feasibility and safety of immediate oral feeding in patients subjected to elective open colorectal surgery. METHODS: This trial included 190 patients who underwent an elective colon or rectal operation. Patients were randomized after the operative procedure into one of two groups. Group I (n = 95): On the first evening after the operation, patients were allowed ab libitum intake of clear liquids; this continued until the first postoperative day at which time they progressed to a regular diet as desired. Group II (n = 95): In this group the nasogastric tube was removed when the surgeon considered that postoperative ileus had been resolved. RESULTS: Early oral intake was tolerated by 79.6% of the patients in the first 4 days in group I; there were no differences between the two groups from the 4th day on. The incidence of vomiting and nasogastric tube insertion (21.5%) was higher in patients in group I than in those in group II. The time until the first bowel movement was 4.3 days in group I and 4.7 days in group II. Complications appeared in 17.3% of the patients in group I and in 19.3% in group II. CONCLUSION: This study has objectively demonstrated that early oral feeding is feasible and safe in patients who have elective colorectal surgery.

Aged↗

Anterior resection: do the patients perceive any clinical benefit?

PURPOSE: Functional results following anterior resection of the rectum have been sparsely reported. Results concerning stool frequency and continence vary widely. These variations may represent several areas of bias, but one of the main concerns is study design. Many studies are focused on physiological results and even when a control population is included in the study design, it is not used to compare the clinical functional outcome. the aims of this prospective study were: (1) to study serially before and 1 year after low anterior resection for carcinoma the changes in clinical function; and (2) to study if these changes could be attributable to the characteristics of the population, comparing the results with sex-matched and age-matched controls. MATERIAL AND METHODS: Sample size was previously established according the prevalence of continence disorders fund in two previous studies carried out in our country, 36% for anterior resection, and 6% among general population in our community. Thirty-eight consecutive patients (mean age 63.9 years, range 41-77 years) with a diagnosis of rectal carcinoma were invited to participate in the study. The lower margin of the tumor was located between 4 and 15 cm from the anal margin (median of level tumor 6.0 cm). A control group of 25 volunteers matched for sex and age with patients who were questioned 1 year after the anterior resection were also studied. Median level of anastomosis was 6.2 +/- 2.7 cm (range 2-11) above the anal margin. In six patients with an anastomosis less than 4 cm from the anal margin, a loop ileostomy was constructed and closed 3 months later. Patients were interviewed by a research assistant before and 1 year after operation or 1 year after closure of the temporary defunctioning loop ileostomy. Patients were questioned about bowel frequency over 24 h, urgency, tenesmus, erratic defecatory patterns, discrimination of bowel content and continence. RESULTS: Clinical function of patients before and after operation. Compared with pre-operative, bowel frequency of 3.9/day (range 0.3-14) did not differ significantly 1 year after operation at 2.3/day (range 0.5-6). Frequency of erratic defecatory patterns (44%), urgency (40%) and obstructed defecation (20%) did not differ between the preoperative and postoperative period. Forty-eight percent of patients suffered tenesmus and 20% were unable to discriminate between flatus and feces before operation, whereas these troublesome symptoms were present in 24% and 16%, respectively, after the operation. Before the operation 32% of patients reported fecal leaks while in the postoperative period 52% patients complained of this alteration. Clinical function of patients compared with controls. Patients had a mean stool frequency per day of 2.3 (range 0.5-6) and controls 1.3 (range 0.3-5). Forty-four percent of patients had erratic defecatory patterns, 24% suffered tenesmus and 40% urgency, whereas these troublesome symptoms were present in 12% in the control population. Moreover, obstructed defecation was present in 20% and 4%, respectively. All controls and 84% of patients maintained discrimination of flatus, liquid and solid feces. Fifty-two percent of patients and 8% of controls suffered from altered continence. CONCLUSIONS: One year after low anterior resection patients had poor bowel function when compared with a control population of the same age and sex. A distinct anterior resection syndrome exists consisting of increased bowel frequency, erratic defecatory patterns, urgency, tenesmus, obstructed defecation, and minor fecal leakage. Furthermore, these disturbances in defecatory function did not differ significantly from symptoms produced by the rectal carcinoma, and patients experienced no major benefit from surgery from a functional point of view.

Adult↗

Early postoperative feeding after elective colorectal surgery is not a benefit unique to laparoscopy-assisted procedures.

UNLABELLED: Previous analyses of non-prospectively randomized trials have suggested that early oral postoperative feeding might be a benefit unique to laparoscopic surgery. However, some authors have indicated that early feeding can be tolerated by the majority of patients after elective open surgery. AIM: This prospective randomized study was undertaken to assess whether the time prior to oral intake of food after laparoscopy-assisted surgery is shorter than that after standard laparotomy. METHODS: This trial included 40 patients who were divided randomly into two groups before operation. Group I included 20 patients (mean age, 52 years; range, 15-77 years) who underwent a laparoscopy-assisted colon or rectal procedure (LAP). Group II consisted of 20 patients (mean age, 56 years, range, 41-74 years) who underwent surgery with a standard midline incision (SMI). On the evening after surgery, patients were allowed clear liquids ab libitum. This regimen was continued until the first postoperative day at which time they could elect to start eating a regular diet. If a patient had two episodes of vomiting, a nasogastric tube was inserted. RESULTS: Five laparoscopic procedures were converted to SMI because of adhesions (25%) and an equal number of patients was excluded from the group that was treated in the traditional manner. Therefore, only 30 patients were included in the analysis. There were no deaths in this trial. Complications appeared in four of the patients in the LAP group and in two of the patients in the SMI group (no significant difference). There were no statistically significant differences between the two groups in terms of the ability to tolerate the early oral intake of food, in the frequency of vomiting or in the incidence of insertion of a nasogastric tube. The time to the first bowel movement was 5.4 days in LAP and 5.5 days in SMI, and the difference was not significant. CONCLUSION: This study invalidates the claim by laparoscopic surgeons that earlier oral intake of food is tolerated by their patients than by patients who undergo standard procedures.

Adolescent↗

Coloanal anastomosis: are functional results better with a pouch?

PURPOSE: Different studies have shown that low colorectal and coloanal anastomosis often yield poor functional results. The aim of the present study was to investigate whether a colonic reservoir is able to improve functional results. METHODS: Thirty-eight consecutive patients subjected to low anterior resection were randomized following rectal excision in two groups. One (n = 19) had a stapled straight coloanal anastomosis, and the other (n = 19) had a 10-cm stapled colonic pouch low rectal anastomosis. Median anastomotic distance above the anal verge was 3.38 +/- 0.56 cm and 2.14 +/- 0.36 cm in both groups, respectively. Continence alterations, urgency, tenesmus, defecatory frequency, anal resting and maximum voluntary squeezing pressures, and maximum tolerable volume were evaluated one year later. RESULTS: One patient died of pulmonary embolism, and seven presented with a recurrence and were excluded from the study. Stool frequency was greater than three movements per day in 33.3 percent of cases with a reservoir and in 73.3 percent of those with a straight coloanal anastomosis (P < 0.05). Maximum tolerable volume was significantly greater in patients with a reservoir (335 +/- 195) than in those without (148 +/- 38) (P < 0.05). There were no significant differences in other variables studied. CONCLUSIONS: This study shows that some aspects of defecatory function after rectal excision could improve with a colonic reservoir.

Aged↗

Univariate and multivariate analysis of risk factors for ovarian cancer: case-control study, Mexico City.

Female residents of the southern part of Mexico City diagnosed with epithelial ovarian cancer between 1989 and 1992 (n = 172) were interviewed regarding reproductive events. The same information was obtained from the controls (n = 441). There was an elevated risk for ovarian cancer associated with an increased number of abortions, relative risk = 3.66 (95% confidence interval = 1.02 - 13.45) for women with four fetal losses. Ovarian cancer risk was shown to decrease as parity increased, reaching a relative risk of 0.23 (95% confidence interval = 0.09 - 0.55) in women with four or more live births in the postmenopausal group. This negative association seems less evident in overall cases. Logistic regression methods were used and abortions and high estimated number of ovulatory cycles were found to be associated with an increased risk of ovarian cancer. The inclusion of nonreproductive variables such as educational status, in the logistic model, showed that cases had a lower educational level than that of controls.

Abortion, Induced↗