Effects of reinforcer choice measured in single-operant and concurrent-schedule procedures.
(41/2366)
The effects of choice and no choice of reinforcer on the response rates of 3 children with autism were compared across single-operant and concurrent-schedule procedures. No consistent differences in responding between choice and no-choice components emerged during single-operant phases. During the concurrent-schedule phases, however, all participants had substantially higher rates of responding to the button that led to a choice among reinforcers than to the button that did not lead to choice. (+info)
Evaluation of a brief multiple-stimulus preference assessment in a naturalistic context.
(42/2366)
We evaluated a brief multiple-stimulus preference assessment within the context of an early intervention program for 3 children who had been diagnosed with autism. Subsequent curriculum-based reinforcer evaluations confirmed the predictions of the preference assessments. In addition, eight additional preference assessments that were conducted over a period of 1 month indicated generally stable preferences for 2 of the 3 participants. (+info)
Second dose of measles, mumps, and rubella vaccine: questionnaire survey of health professionals.
(43/2366)
OBJECTIVE: To determine the knowledge, attitudes, and practices among health professionals regarding the measles, mumps, and rubella (MMR) vaccine, particularly the second dose. DESIGN: Self administered postal questionnaire survey. SETTING: North Wales Health Authority, 1998. PARTICIPANTS: 148 health visitors, 239 practice nurses, and 206 general practitioners. MAIN OUTCOME MEASURES: Respondents' views on MMR vaccination, including their views on the likelihood of an association with autism and Crohn's disease and on who is the best person to give advice to parents, whether they agree with the policy of a second dose of the vaccine, and how confident they are in explaining the rationale behind the second dose. RESULTS: Concerning the second dose of the vaccine, 48% of the professionals (220/460) had reservations and 3% (15) disagreed with the policy of giving it. Over half the professionals nominated health visitors as the best initial source of advice on the second vaccine. 61% of health visitors (86/140), compared with 46% of general practitioners (73/158), reported feeling very confident about explaining the rationale of a two dose schedule to a well informed parent, but only 20% (28/138) would unequivocally recommend the second dose to a wavering parent. 33% of the practice nurses (54/163) stated that the MMR vaccine was very likely or possibly associated with Crohn's disease and 27% (44/164) that it was associated with autism. Nearly a fifth of general practitioners (27/158) reported that they had not read the MMR section in the "green book," and 29% (44/152) reported that they had not received the Health Education Authority's factsheet on MMR immunisation. CONCLUSIONS: Knowledge and practice among health professionals regarding the second dose of the MMR vaccine vary widely. Many professionals are not aware of or do not use the good written resources that exist, though local educational initiatives could remedy this. (+info)
Analyzing the multiple functions of stereotypical behavior for students with autism: implications for assessment and treatment.
(44/2366)
We studied behavioral functions associated with stereotypical responses for students with autism. In Study 1, analogue functional analyses (attention, demand, no-attention, and recreation conditions) were conducted for 5 students. Results suggested that stereotypy was multiply determined or occurred across all assessment conditions. For 2 students, stereotypy was associated with positive and negative reinforcement and the absence of environmental stimulation. For 2 other students, stereotypy occurred at high levels across all experimental conditions. For the 5th student, stereotypy was associated with negative reinforcement and the absence of environmental stimulation. In Study 2, the stereotypy of 1 student was further analyzed on a function-by-function basis. Within a concurrent-schedules procedure, alternative responses were taught to the student using functional communication training. The results of Study 2 showed that similar topographies of stereotypy, based on qualitatively different reinforcers, were reduced only when differential reinforcement contingencies for alternative forms of communication were implemented for specific response-reinforcer relations. Our results suggest that the causes of stereotypy for students with autism are complex and that the presumed association between response topography and behavioral function may be less important than previously realized. (+info)
Teaching children with autism to ask questions about hidden objects.
(45/2366)
We taught 2 4-year-old children with autism to ask questions of an adult who held a closed box with a toy inside. The treatment package (modeling, prompting, and reinforcement) was evaluated with a multiple baseline design across the three question forms during training, generalization, and follow-up evaluations. The first question form ("What's that?") produced the name of the hidden item. The second form ("Can I see it?") produced sight of it, and the third form ("Can I have it?") produced the item itself. Both children learned to ask questions about hidden objects. (+info)
Mumps, measles, and rubella vaccine and the incidence of autism recorded by general practitioners: a time trend analysis.
(46/2366)
OBJECTIVE: To estimate changes in the risk of autism and assess the relation of autism to the mumps, measles, and rubella (MMR) vaccine. DESIGN: Time trend analysis of data from the UK general practice research database (GPRD). SETTING: General practices in the United Kingdom. SUBJECTS: Children aged 12 years or younger diagnosed with autism 1988-99, with further analysis of boys aged 2 to 5 years born 1988-93. MAIN OUTCOME MEASURES: Annual and age specific incidence for first recorded diagnoses of autism (that is, when the diagnosis of autism was first recorded) in the children aged 12 years or younger; annual, birth cohort specific risk of autism diagnosed in the 2 to 5 year old boys; coverage (prevalence) of MMR vaccination in the same birth cohorts. RESULTS: The incidence of newly diagnosed autism increased sevenfold, from 0.3 per 10 000 person years in 1988 to 2.1 per 10 000 person years in 1999. The peak incidence was among 3 and 4 year olds, and 83% (254/305) of cases were boys. In an annual birth cohort analysis of 114 boys born in 1988-93, the risk of autism in 2 to 5 year old boys increased nearly fourfold over time, from 8 (95% confidence interval 4 to 14) per 10 000 for boys born in 1988 to 29 (20 to 43) per 10 000 for boys born in 1993. For the same annual birth cohorts the prevalence of MMR vaccination was over 95%. CONCLUSIONS: Because the incidence of autism among 2 to 5 year olds increased markedly among boys born in each year separately from 1988 to 1993 while MMR vaccine coverage was over 95% for successive annual birth cohorts, the data provide evidence that no correlation exists between the prevalence of MMR vaccination and the rapid increase in the risk of autism over time. The explanation for the marked increase in risk of the diagnosis of autism in the past decade remains uncertain. (+info)
A case-control study of autism and mumps-measles-rubella vaccination using the general practice research database: design and methodology.
(47/2366)
BACKGROUND: An association between mumps-measles-rubella (MMR) vaccination and the onset of symptoms typical of autism has recently been suggested. This has led to considerable concern about the safety of the vaccine. METHODS: A matched case-control study using data derived form the United Kingdom General Practice Research Database. Children with a possible diagnosis of autism will be identified from their electronic health records. All diagnoses will be validated by a detailed review of hospital letters and by using information derived from a parental questionnaire. Ten controls per case will be selected from the database. Conditional logistic regression will be used to assess the association between MMR vaccination and autism. In addition case series analyses will be undertaken to estimate the relative incidence of onset of autism in defined time intervals after vaccination. The study is funded by the United Kingdom Medical Research Council. DISCUSSION: Electronic health databases offer tremendous opportunities for evaluating the adverse effects of vaccines. However there is much scope for bias and confounding. The rigorous validation of all diagnoses and the collection of additional information by parental questionnaire in this study are essential to minimise the possibility of misleading results. (+info)
Do children who become autistic consult more often after MMR vaccination?
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A close temporal association has been reported between the measles, mumps, and rubella (MMR) vaccination and dramatic behavioural decline in children subsequently diagnosed as autistic. We hypothesised that such a decline would be reflected in increased consultations with the child's general practitioner. The Doctor's Independent Network database was used to examine whether children subsequently diagnosed as autistic consulted more frequently than controls after MMR vaccination. No difference in consulting behaviour was seen in the six months post MMR. Any dramatic effect of MMR on behaviour seems unlikely. (+info)