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Results for “Randomized Response Technic”

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PubMed2001

The effect of botulinum toxin type A on the functional ability of the child with spastic hemiplegia a randomized controlled trial.

It has been demonstrated that botulinum toxin type A (BTX-A) injections reduce spasticity and improve muscle growth in children with spasticity. It has been postulated that BTX-A allows the learning of more normal movement patterns. The aim of this study was to measure the effect of this treatment on functional ability, as measured by the Gross Motor Function Measure (GMFM), in children with spastic hemiplegic cerebral palsy. Children of 3--13 years and meeting the selection criteria were randomly allocated to the control or injection group using a matched pair design. A match constituted a child within 6 months of age with the same Modified Ashworth Score (MAS) for the gastroc-soleus and within 10% of the same goal scores on the Gross Motor Function Measure. Twelve matched pairs were enrolled. Outcomes were measured on enrolment and at 1, 3 and 6 months post injection. The time course of the response to BTX-A was assessed with measurements of the MAS, dynamic range of motion (R1) and static muscle length (R2). Motor function was assessed using the 88-item GMFM and parental satisfaction with a 10-point visual analogue scale. Within pair comparisons of the GMFM using the Wilcoxon signed rank test indicated that the treatment group made significantly greater gains than controls at 3 months (P=0.02) with even greater differences seen at 6 months (P=0.004). Using parametric statistics, the intrapair difference in proportional change of GMFM increased from 35% (4 to 65) at 3 months to 52% (17--87) at 6 months. Response to injection was confirmed by a decrease in MAS in the treatment group and very little change in controls. This difference was significant (P=0.002) at 3 months and was attenuated but still significant (P=0.016) at 6 months; the difference in proportional change decreased from 44% at 3 months to 22% at 6 months. Changes in R1 reflected those of MAS in the treatment group and deteriorated significantly over the study period in controls. Parents of children in the treatment group were more satisfied than controls, but satisfaction scores did not correlate with changes in function or technical outcomes suggesting that this may be a placebo effect. The changes in GMFM correlated with changes in technical outcomes at 3 months, suggesting a causal relationship. The intrapair differences in GMFM continued to increase even after the local response to injection had started to wane.

Adolescent↗

PubMed1990

[Requirements for the randomized trial of i.a. vs. i.v. administration to reveal the impact of hepatic arterial infusion on survival in the treatment of liver metastases].

In spite of its high response rate, the impact of hepatic arterial infusion (HAI) chemotherapy on survival is still uncertain in the treatment of liver metastases. There were no significant differences in survival between i.a. and i.v. in western randomized trials for liver metastases from colorectal cancer in the 1980s. The requirements for randomized trials between i.v. and i.a. administration for liver metastases to reveal the impact of HAI on survival are as follows. 1) Investigators have standardized the technical level for HAI. 2) The natural history of the disease is not so long for continuing HAI over living period. 3) The cases have no extra-hepatic lesions. 4) The number of patients suffices for the evaluation. Therefore, the patients with liver metastases from gastric cancer and without extra-hepatic lesions are better materials for the randomized trial of i.a. vs i.v. in Japan, and the multiinstitutional trial with standard technical level is recommended.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1993

Tightening the clinical trial.

Randomized clinical trials adhere more closely to pre-agreed-on protocols than almost any other type of experiment, yet we can tighten up their analysis if we desire. If we convert the analysis into a randomization analysis--where the one set of data is analyzed many times--once as though each acceptable assignment has been employed, we can eliminate any dependence of the analysis on statistical or probabilistic assumptions. To do this effectively when many assignments could be acceptable, we can go to double randomization, in which a subset, usefully kept balanced, of acceptable assignments is selected (perhaps randomly) before data acquisition. If we have one covariate, adjustment for which answers a question that is at least as appropriate, we can easily build on this. Imperfect covariance adjustments can help almost as much as perfect ones. If it is appropriate to work with many covariate(s), it is often desirable to first construct a (few) compound covariate(s) and then work with it (them). Often we can base the coefficients in our compound covariate on the univariate regressions of response on single covariates. Doing this within each arm of the trial and pooling keeps the fitting of the final adjustment unbiased. Since we can prespecify how the compounds are to be calculated and fitted, we can do all this while retaining rigid prespecification. Prespecification, randomization, and intelligent use of covariates combined to make the resulting significance analysis of platinum standard quality. (If we want confidence statements, as we ordinarily should, it may make sense, for technical reasons, to plan for somewhat less than platinum standard quality).

Humans↗

PubMed2004

A randomized evaluation of two health care quality improvement program (HCQIP) interventions to improve the adequacy of hemodialysis care of ESRD patients: feedback alone versus intensive intervention.

End-stage renal disease (ESRD) Networks are quality improvement organizations that collect, analyze, and report information to clinicians and allied health providers about discrepancies between observed patterns of care of ESRD patients and what has been recommended by clinical practice guidelines. The Networks facilitate response to this information by assisting ESRD treatment centers to develop quality improvement programs to redress inadequate care. The authors evaluated this process of quality improvement by selecting 42 treatment centers in a single ESRD Network with the lowest facility-specific mean urea reduction ratio (URR). The treatment centers were randomly assigned to two intervention strategies: (1) feedback alone; (2) an intensive intervention that included feedback, workshops, distribution of educational materials and clinical practice guidelines, technical assistance with the development of quality improvement plans, and continued monitoring. The intensive intervention had greater improvement in the increased proportions of patients dialyzed with prescribed blood flow (P = 0.02) and documented review of prescription (P = 0.01). Furthermore, the mean center URR increased nearly 3% among intensive intervention centers (from 68.1 to 70.9) but only 0.09% among the feedback centers (68.2 to 69.1) (P = 0.002). Similarly, time on dialysis increased 7.5 min on average among patients in intervention centers but decreased 2 min for patients in comparison centers (P = 0.03). These results demonstrate that Network feedback, coupled with the intensive intervention, resulted in improvement in care that would otherwise not have occurred.

Feedback↗

PubMedDate not supplied

Thermal control and design considerations for a high-performance fluid warmer.

The process of warming liquids for intravenous infusion presents several technical challenges for the engineer: Typical liquid inlet temperatures can range from 5 degrees C to 20 degrees C, flow requirements can vary from essentially zero ("Keep Vein Open," or K.V.O.) to 30 L/h, and desired outlet temperature is fixed at a maximum threshold of 41 degrees C to minimize the risk of thermally mediated hemolysis. The primary challenge is developing a control technique that can tailor the energy introduced to the liquid in response to a randomly variable flow in order to achieve, but not exceed, a fixed temperature. The most difficult aspect of this challenge is preventing the transient infusate temperature from exceeding 43 degrees C, even when the power requirement varies by orders of magnitude, such as occurs when the flow suddenly decreases from maximum to zero. Many current-generation fluid warmers are optimized for operation at either low or high flow rates; we believed that it was possible to design an easy-to-use device that could achieve good performance across the entire range of flow rates. This article describes some of the methods that were used successfully to meet these challenges in the design of the Augustine Medical Ranger blood fluid warmer.

Blood↗

PubMed1996

Specificity of diagnostic nerve blocks: a prospective, randomized study of sciatica due to lumbosacral spine disease.

Temporary nerve blocks using local anesthetic are employed extensively in the evaluation of pain problems, particularly lumbosacral spine disease. Their specificity and sensitivity in localizing anatomic sources of pain have never been studied formally, however, and so their diagnostic and prognostic value is questionable. There have been anecdotal reports of relief of pain by temporary blocks directed to areas of pain referral, as opposed to areas of documented underlying pathology; but there has been no study to define the frequency or magnitude of this effect. We have examined the specificity and sensitivity of a battery of local anesthetic blocks in a series of 33 patients with a chief complaint of sciatica, attributable in all cases to spinal disease (radiculopathy, with some clinical features of arthropathy). As determined by blinded patient analog ratings in randomized sequence, three different nerve blocks were significantly more effective than control lumbar subcutaneous injection of an identical volume of 3 ml of 0.5% bupivacaine (P < 0.05). Not only paraspinal lumbosacral root blocks and medial branch posterior primary ramus blocks (at or proximal to the pathology), but also sciatic nerve blocks (distal or collateral to the pathology) produced temporary relief in a majority of patients. This confirmed the study hypothesis that false positive results are common, and specificity is low. For sciatic nerve blocks, specificity was between 24% and 36%. Patterns of responses specific to the established diagnosis of radiculopathy (i.e., root block most effective) had sensitivities between 9% and 42%. Statistical analysis of clinical and technical prognostic factors revealed that the only association with pain relief by any block were the effects of other blocks. The strongest association was between relief by sciatic nerve block and relief by medial branch posterior primary ramus (facet) block (P = 0.001, odds ratio 16.0). There were no associations between the results of blocks and clinical findings (history, physical examination, diagnostic imaging) in these patients, chosen for their homogeneous clinical presentation and absence of functional signs. Our findings indicate a limited role for uncontrolled local anesthetic blocks in the diagnostic evaluation of sciatica and referred pain syndromes in general. Negative blocks or a pattern of responses may have some predictive value, but isolated, positive blocks are non-specific. This lack of specificity may, however, be advantageous in therapeutic applications.

Adult↗

PubMed2001

Brain microembolic counts during extracorporeal circulation depend on aortic cannula position.

Thrombofibrinous and gaseous brain microemboli are commonly observed during extracorporeal circulation in patients undergoing cardiac surgery. Recent studies showed a preference of microemboli to the left hemisphere. We hypothesized that placement of the aortic cannula tip within the aorta descendens rather than in the aorta ascendens as commonly used reduces the number of microemboli to the brain and also reduces the side preference. Of 60 patients undergoing elective coronary artery bypass grafting primarily randomized to either a short aortic cannula (aorta ascendens) or an elongated one (aorta descendens), 29 (16 and 13) patients had complete and technically perfect continuous intraoperative transcranial Doppler sonography with embolus detection bilaterally. The number of high-intensity transient signals (HITS) was 994 +/- 2118 (mean +/- SD) for the short cannula group and was significantly lower with the elongated cannula (223 +/- 208; p < 0.02). HITS counts per min also differed significantly in favour of the aorta descendens group (p < 0.02), but there was an overlap. Thus, elongated cannulas can reduce, but not prevent microembolism to the brain. The side-to-side ratio of microemboli revealed more events in the left hemisphere, but this was similar in both groups. This suggests that individual anatomic factors may be responsible for this hemodynamically-mediated effect.

Aorta↗

PubMed1988

Dutch dentists' decisions to take bitewing radiographs.

A postal questionnaire was sent to a 10% (n = 444) national random sample of Dutch dental practitioners. The response was 77% (n = 344). The practitioners prescribed bitewings on average for 57% of "new" 25-yr-old patients. Five significant (P less than 0.05) variables explained 24% of the variation in bitewing prescribing for these "new" patients. These were, in declining level of importance: the initial dental condition of the patient, the proportion of restorative treatment decisions based solely on radiographs, the level of urbanization of the practice location, the technical level of the practice equipment and the importance attached by dentists to the diagnostic use of dental floss for interproximal caries diagnosis. The low power of the regression model in explaining variation in the decision to take bitewings indicates an idiosyncratic use of bitewing radiographs for caries diagnosis. A weak tendency to adopt different diagnostic sets of procedures was demonstrated.

Adolescent↗

PubMed2006

Patients' satisfaction with dental care provided by public dental clinics in Dar es Salaam, Tanzania.

BACKGROUND: In Tanzania, patient satisfaction with dental services has received only minor attention. OBJECTIVE: To assess patients' satisfaction with public dental health services in Dar es Salaam. DESIGN: A cross-sectional study. SETTING: Five public dental clinics randomly selected from a list of all the nine public dental clinics in Dar es Salaam. SUBJECTS: Five hundred and sixteen consecutive patients, 193 males and 323 females aged between 12 and 77 years who, during the study period between July and November, 2002 were attending five dental clinics were randomly selected. RESULTS: No significant differences in patients' satisfaction level (overall or for the specific studied items) were found in all the five public dental clinics. The answers to the specific sub-items, apart from time spent with doctor, were around the average with very few responses with a high ranking. CONCLUSIONS: Findings indicate a moderate level of patient satisfaction with dental care offered in public dental clinics in Dar es Salaam. Areas identified as needing improvement included; technical quality of care, interpersonal aspects and communication.

Adolescent↗

PubMed2005

[Popliteal fossa sciatic nerve block for ambulatory hallux valgus surgery: comparison of lateral and posterior approaches].

OBJECTIVE: The aim of this study was to assess the efficacy, effectiveness, technical difficulty, and clinical usefulness of the popliteal sciatic peripheral nerve block for unilateral hallus valgux surgery and to compare the posterior and lateral approaches. We also aimed to investigate patient comfort during the procedure. MATERIALS AND METHODS: This prospective, randomized trial enrolled 60 patients scheduled for unilateral hallux valgus surgery. The patients were randomly assigned to groups of 30 patients to receive a nerve block by either a posterior or lateral approach. A nerve stimulator was used to locate the response of the two branches forming the sciatic nerve--the posterior tibial nerve and the common peroneal nerve. Then, 20 mL of 0.5% ropivacaine was injected for each nerve. Variables analyzed were efficacy, complications, quality and duration of postoperative analgesia, degree of comfort while the technique was being performed, and level of satisfaction. RESULTS: The level of comfort was good for 19 patients (70%) in the posterior approach group and for 29 (97%) in the lateral approach group (P<0.05). Level of satisfaction was good or very good for 93% and 96% of the patients in the posterior and lateral approach groups, respectively. Block efficacy was excellent for 48 patients (80%), good for 9 (15%), and poor for 3 (5%), with no significant differences between the groups. CONCLUSION: Both the posterior and lateral approaches provide easy access to the sciatic nerve for performing a block. The rate of success is high and postoperative analgesia is good, with no noteworthy complications. However, the lateral approach is more comfortable for the patient.

Adult↗

PubMed1989

Comparison of job expectations fulfillment of BS and entry-level PharmD graduates in hospital and community practice.

Job expectations are an important link between work and subsequent employee mental and physical well-being. Schools and colleges play an important role in the development of job expectations. This role gives them the responsibility of not only technically training students but also instilling in them realistic job previews and career expectations. Failure to do so places the graduate in a state of conflict between the reality of work in his/her chosen career and his/her preconceived expectations regarding the work. This state represents a potential source of job-related stress. BS and entry level PharmD training programs represent two approaches to pharmaceutical education in a practice environment which remains essentially the same for graduates of both programs. As such, there is the potential for a mismatch of job expectations resulting from one or both of the degree types. The present study investigated the following research questions: (i) to what extent are job expectations being fulfilled for pharmacists in hospital and community pharmacy; and (ii) in community and hospital practice, does the fulfillment of job expectations of BS and entry level PharmD graduates differ? Questionnaires were mailed to randomly selected 1980 to 1986 graduates of seven schools or colleges of pharmacy to elicit responses regarding fulfillment of job expectations in their present community or hospital pharmacy positions. The response rate was 48 percent. The subsequent data revealed that pharmacists generally felt that their job expectations were being fulfilled. No differences in overall fulfillment of job expectations were found between BS and entry level PharmD graduates in either community or hospital pharmacy practice.(ABSTRACT TRUNCATED AT 250 WORDS)

Attitude of Health Personnel↗

PubMed2002

A straw man proposal for a quantitative definition of the RfD.

This paper discusses the merits and disadvantages of a specific proposal for a numerical calculation of the reference dose (RfD) with explicit recognition of both uncertainty and variability. It is suggested that the RfD be the lower (more restrictive) value of: The daily dose rate that is expected (with 95% confidence) to produce less than 1/100,000 incidence over background of a minimally adverse response in a standard general population of mixed ages and genders, or The daily dose rate that is expected (with 95% confidence) to produce less than a 1/1000 incidence over background of a minimally adverse response in a definable sensitive subpopulation. Developing appropriate procedures to make such estimates poses challenges. To be a viable replacement for current RfDs, a numerical definition needs to be A plausible representation of the risk management values that both lay people and "experts" believe are intended to be achieved by current RfDs, (while better representing the "truth" that current RfDs cannot be expected to achieve zero risk with absolute confidence for a mixed population with widely varying sensitivities), Estimable with no greater amount of chemical specific information than is traditionally collected to estimate current RfD values, Subjected to a series of comparisons with existing RfDs to evaluate overall implications for current regulatory values, A more flexible value in the sense of facilitating the development of procedures to allow the incorporation of more advanced technical information--e.g., defined data on human distributions of sensitivity; information on comparative pharmacokinetic and/or pharmacodynamics in humans vs. test species, etc. The discussion evaluates the straw man proposal in the light of each of these points, and assesses the risks and uncertainties inherent in present RfDs by applying existing distributional information on various uncertainty factors to 18 of 20 randomly-selected entries from IRIS. The analysis here suggests that current RfDs seem to meet the 1/100,000 risk criterion with only somewhat better than 50% confidence. However, the current RfDs appear to generally fall short of the goal of meeting this risk criterion with 95% confidence, typically by an order of magnitude in dose or somewhat more. The single most important uncertainty is the extent of human interindividual variability in the doses of specific chemicals that cause adverse responses. Our major conclusion is that with some important assumptions, it is currently feasible to both specify quantitative probabilistic performance objectives for RfDs and to make tentative assessments about whether specific current RfDs for real chemicals seem to meet those objectives. Similarly it is also possible to make preliminary estimates of how much risk is posed by exposures in the neighborhood of current RfDs, and what the uncertainties are in such estimates. It is therefore possible to harmonize cancer and noncancer risk assessments by making quantitative noncancer risk estimates comparable to those traditionally made for carcinogenic risks. The benefits from this change will be an increase in the candor of public discussion of the possible effects of exposures to chemicals posing non-cancer risks, and encouragement for the collection of better scientific information related to toxic risks in people--particularly the extent and distributional form of interindividual differences among people in susceptibility.

Animals↗

PubMed2002

Combined-modality treatment for resectable metastatic colorectal carcinoma to the liver: surgical resection of hepatic metastases in combination with continuous infusion of chemotherapy--an intergroup study.

PURPOSE: Despite technical improvements that have minimized the morbidity and mortality of hepatic surgery, the long-term outcome of resection of hepatic metastases of colorectal cancer remains poor, with the majority of patients experiencing treatment failure in the liver. Because arterial chemotherapy regimens targeted to the liver have demonstrated high response rates, an intergroup trial of adjuvant therapy for patients undergoing hepatic resection of liver metastases from colorectal cancer was initiated. PATIENTS AND METHODS: Patients with one to three potentially resectable metastases were randomized preoperatively to receive no further therapy (control arm, 56 patients) or postoperative hepatic arterial floxuridine combined with intravenous continuous-infusion fluorouracil (chemotherapy arm, 53 patients). After exclusion of patients identified as ineligible for the planned treatment at the time of surgery, there were 45 control patients and 30 on the chemotherapy arm. The study was powered to evaluate improvement in time to recurrence and hepatic disease-free survival, not overall survival. RESULTS: The 4-year recurrence-free rate was 25% for the control arm and 46% for the chemotherapy group (P =.04). The 4-year liver recurrence-free rate was 43% in the control group and 67% in the chemotherapy group (P =.03). The median survival of the 75 assessable patients was 49 months for the control arm and 63.7 months for the chemotherapy arm (P =.60). The median survival of all 109 patients was 47 months for the control arm compared with 34 months for the chemotherapy arm (P =.19) CONCLUSION: These data demonstrate that adjuvant intra-arterial and intravenous chemotherapy was beneficial in prolonging time to recurrence and pre-venting hepatic recurrence after hepatic resection of colorectal cancer.

Antimetabolites, Antineoplastic↗

PubMed1989

Management activities in community dietetics practice.

Information on the management activities of community dietitians was obtained through a mail survey of 350 randomly selected community dietitians. Subjects provided information on their management level, the importance to their job performance of 83 management activity statements, and the percent of time they spent performing management activities in each of nine categories. Twenty-nine percent of the respondents indicated job responsibilities in lower-level management; 45% had mid-level and 26% had upper-level management responsibilities. Numbers of activities rated essential or very important increased as management levels increased. Kinds of activities changed from technical to human to conceptual as management levels increased. Mid-level management subjects, while still spending time working with clients, reported spending considerable time on coordinating, investigating, and evaluating, often reporting as much time spent on those activities as did upper-level management subjects. Definitions provided by respondents indicated great diversity in job requirements and settings.

Community Health Services↗

PubMed2000

Hepatic arterial 5-fluorouracil in patients with liver metastases of colorectal cancer: single-centre experience in 145 patients.

BACKGROUND: Hepatic arterial chemotherapy for liver metastases of colorectal cancer is still under discussion. Mainly because of the technical complications of this mode of treatment and the lack of a survival benefit in randomized studies. We performed an analysis of hepatic arterial 5-fluorouracil (5-FU) chemotherapy in 145 consecutive patients treated at a single institution. PATIENTS AND METHODS: One hundred forty-five patients with inoperable liver metastases from colorectal cancer were included. 5-FU, 1000 mg/m2/day continuous infusion for five days every three weeks, was delivered in the hepatic artery by percutaneous catheter or arterial access device. RESULTS: The response rate was 34% for all patients, 40% in patients with extrahepatic disease, and 15% in patients with i.v. 5-FU-based pretreatment. TTP and OS for all patients were 7.5 and 14.3 months, respectively. In patients with extrahepatic disease or i.v. 5-FU-based pretreatment, OS was significantly shorter compared to patients without extrahepatic disease or 5-FU-based pretreatment (9.7 vs. 19.3 months and 10.1 vs. 17.4 months, respectively), forty-seven percent of patients stopped treatment because of a complication. Complications most often seen in patients with arterial ports were hepatic artery thrombosis (48%) and dislocation of the catheter (22%). CONCLUSIONS: The results of our analysis are in line with previous phase III studies. Extrahepatic disease and i.v. 5-FU-based pretreatment were prognostic for reduced OS. The complication rate of hepatic arterial delivery was worrisome. although, no negative impact on survival could be established. There is a strong need for improvement of hepatic arterial delivery methods before further evaluation of hepatic arterial

Adult↗

PubMed1999

Private or NHS General Dental Service care in the United Kingdom? A study of public perceptions and experiences.

BACKGROUND: Recent changes in the NHS General Dental Service have led to a reduction in the availability of NHS dental care and increased charges. This study explores public and user views and experiences of NHS and private dental care in the light of these changes. METHODS: The study employed a combination of quantitative and qualitative methods. The first phase involved a postal survey of a random sample of adults on the electoral registers in a county in Southern England, which yielded a response rate of 55 per cent (n = 1506). Follow-up face-to-face interviews were carried out with sub-samples (n = 50) selected from survey respondents. RESULTS: The evidence shows greater satisfaction with certain aspects of private care than with NHS dental care and suggests that the decline in perceived quality of NHS care is less to do with the quality of dental technical skills and more to do with perceived access and availability. However, there was general support for the egalitarian principles associated with NHS dentistry, although payment for dental care by users was acceptable even though dentistry on the NHS was preferred. CONCLUSION: The shift in the balance of NHS and private dental care reflects the interests and preferences of dentists rather than of the public. It suggests, however, that a continued shift towards private practice is a trend that the public will not find acceptable, which might limit the extent of expansion of private practice.

Adult↗

PubMedDate not supplied

[Choice of doses in the treatment of osteoporosis].

The choice of dosing of osteoporosis drugs should lie upon appropriate studies, indicating particularly the minimal efficient dosing which is, in this area, of a particular importance. Because of technical difficulties in the realisation, very few studies have been reported at the present time. From a practical point of view, the good choice of dosing of anti osteoporotic drugs must be studied from dose-response relationship curvus at the beginning of phase III clinical studies. From literature, it appears that the supposed optimal dosing of anti osteoporotic drugs have frequently been assessed empirically or from studies with patent methodological errors. Such studies should be on the contrary, prospective in parallel groups, randomized, double-blinded, using a pertinent, validated and more sensitive criteria of response.

Calcitonin↗

PubMed1989

A cytogenetic investigation of the effects of cryopreservation on human sperm.

The effects of cryopreservation on the frequency and type of chromosome abnormalities in human sperm have been investigated for the first time. With a technique which enables direct visualization of human sperm chromosomes following in vitro penetration of hamster oocytes, sperm samples from 13 normal men were examined before and after being frozen in liquid nitrogen. The overall abnormality frequencies of 17.8% for fresh semen and 13.4% for previously frozen semen were not significantly different (chi 2(1) df = 3.04, p = 0.08). When specific abnormality types were analyzed, only the category of hypohaploidy was significantly different (chi 2(1) df = 6.75, p = 0.009) before (7.5%) and after (3.4%) freezing. Hypohaploidy was significantly higher than hyperhaploidy both prefreeze and postfreeze, and chromosome loss was random. Because the observed excess of hypohaploid cells may be attributable to technical artifact, the aneuploidy levels were estimated by doubling the number of hyperhaploid cells. Neither the adjusted numerical abnormality frequencies (1% prefreeze vs. 0% postfreeze) nor the overall abnormality frequencies (11.8% prefreeze vs. 10.4% postfreeze) were significantly different. The types and distributions of karyotypically abnormal sperm complements (numerical, structural, or combined) observed before and after freezing were not different. Interdonor variability in sperm chromosome abnormality frequencies and a possible donor-dependent response to cryopreservation were suggested by the data. The sex ratios were not affected by cryopreservation and did not differ significantly from the theoretical 50%. It is concluded that cryopreservation does not affect the type or frequencies of chromosome abnormalities or alter the sex ratio in human sperm.

Aneuploidy↗