A survey of expanded duties usage in Indiana: a pilot study

PURPOSE

The information presented in this pilot study was obtained as part of a 1990 survey of Indiana dentists. This portion of the study determined the number and types of expanded duties delegated to dental hygienists and the relationship of this information to their employer's year of graduation.

METHODS

A 10% random sample of Indiana dentists was sent a questionnaire that asked each practitioner's specialty and year of graduation from dental school. In addition, the number of dental hygienists and assistants employed in the practice and the frequency of selected expanded function procedures they performed were determined. Statistical treatment of the survey data was accomplished by frequency tabulations on procedures delegated; principal component analysis applied to a select number of measures; and Student's t-test to variables related to office environment (total years experience, total staff, percentage employing dental hygienists, percentage employing full-time dental hygienists, number of procedures employed, and graduation year of dentist). The level of significance selected for the t-test analysis was .05.

RESULTS AND CONCLUSIONS

Seventy-four questionnaires were returned out of 231 mailed (32% response rate). Of the expanded functions listed on the survey, the procedures most widely delegated to dental hygienists were amalgam polishing and sealant placement. The placement of resin and amalgam restorations was rarely performed by dental hygienists. Based on a principal component analysis, two office environments were defined. Type A offices had dentists with a mean graduation date of 1965.9. Type B offices had dentists with a mean graduation date of 1977.8, significantly larger staff sizes, and employed a higher percentage of full-time dental hygienists. Moreover, dental hygienists employed in Type B offices also performed a greater number of expanded function procedures than did dental hygienists in Type A offices.

Pitfalls inherent in retrospective time-to-event studies: the example of time to pregnancy

Retrospective studies of time from initiation of risk (for example, transfusion of HIV-infected blood) to the occurrence of an endpoint of interest are useful in epidemiology. One example is studies of time to pregnancy, which have evaluated exposures that may affect human fertility. One can reconstruct the non-contracepting interval required for each woman's most recent pregnancy and then treat the data as if the couples had been studied prospectively. As we illustrate, however, failure-time models can be dangerously misleading when there have been trends over calendar time in exposures under study. We propose an ad hoc method for evaluating possible effects on fertility despite this bias, by making use of external data on trends in the exposure over time. This approach applies a prospective model and generates an empirical p-value, based on comparing the data-based estimated exposure coefficient with its null distribution estimated by simulation. A second method maximizes a conditional likelihood, and we show that this is equivalent to logistically modelling the relative odds for the subject's exposure as related to the reported time she required to achieve pregnancy.

Delegation of expanded functions to dental assistants and hygienists

One hundred and twenty-six dental offices in Washington State kept a record of each time an expanded function was performed by the dentist, hygienist, or assistant. There were five two-week recording periods starting in February 1979 and ending in February 1981. Consistent with increasing productivity, dentists most frequently delegate tasks to dental assistants rather than dental hygienists and delegate an individual task consistently if it is delegated at all. For tasks that may be delegated to the assistant, a relationship was found between the per cent of dentists delegating an individual task and the amount of the dentist's time that is freed through delegating that task. From the perspective of quality of care, the per cent of dentists who delegate a task was inversely related to the complexity of the task.

What is an operating auxiliary? Legal status, training and utilization

This paper describes present trends in the training and utilization of dental auxiliaries in the United States of America and examines the situation in the State of California in greater detail. Ninety-one per cent of al single-handed practitioners in the USA employ a dental assistant and 45 per cent employ a hygienist. Almost one-third of American dentists employ four or more auxiliary personnel. Because of increasing competition from other more remunerative forms of employment and a fall in the number of young people of the appropriate age group, there has been a decline in the enrollment in dental auxiliary education programs. In the early part of the past decade there was government pressure to secure an increased use of expanded function dental auxiliaries as a means of limiting the cost of dental care. However, there is evidence that as a result of overproduction of dental graduates the utilization of auxiliaries may decline in coming years. At present, five categories of dental auxiliary are recognized in California, namely, the dental assistant, registered dental assistant (RDA), registered dental assistant in extended functions (RDAEF), registered dental hygienist (RDH) and registered dental hygienist in extended functions (RDHEF).