Response rates for surveys of chiropractors.

BACKGROUND: Survey response rates may vary by type of practitioner studied and may have declined over time. Response rates for surveys of complementary practitioners have not been studied. OBJECTIVE: To describe the response rates in published surveys of chiropractors and explore for secular trends in response rates and for methodologic and geographic correlates of response rates. METHODS: Secondary analysis of data extracted from published English language reports of surveys of chiropractors. Response rates were calculated as the total number of persons from whom a questionnaire was returned divided by the total number of persons who were sent a questionnaire. RESULTS: Sixty-two surveys represented by 79 articles published in the interval 1980 to 2000 met inclusion criteria for analysis. We were able to calculate a response rate for 46 postal surveys. The mean response rate was 52.7%. There was no significant association between geographic setting and response rate, and there was no evidence of secular trend in response rates. None of the studies employed incentives. The strongest predictor of response rate was number of contacts with the target population. CONCLUSION: Response rates for surveys of chiropractors are similar to those observed for surveys of medical doctors. The key to obtaining high response rates is the use of evidence-based methods in design and conduct of the surveys.

Chiropractors and vaccination: A historical perspective.

Although there is overwhelming evidence to show that vaccination is a highly effective method of controlling infectious diseases, a vocal element of the chiropractic profession maintains a strongly antivaccination bias. Reasons for this are examined. The basis seems to lie in early chiropractic philosophy, which, eschewing both the germ theory of infectious disease and vaccination, considered disease the result of spinal nerve dysfunction caused by misplaced (subluxated) vertebrae. Although rejected by medical science, this concept is still accepted by a minority of chiropractors. Although more progressive, evidence-based chiropractors have embraced the concept of vaccination, the rejection of it by conservative chiropractors continues to have a negative influence on both public acceptance of vaccination and acceptance of the chiropractic profession by orthodox medicine.

The subcellular distribution and properties of Crithidia sp. hydrolases with particular reference to pyrophosphate and orthophosphate monoester phosphohydrolases.

A cell fractionation scheme was developed for studying the distribution of certain hydrolases, especially phosphohydrolases in a Crithidia sp. (Trypanosomatidae). Whilst between 26-56% of the total cellular hydrolase activities were soluble (probably of flagellar pocket origin), a certain percentage, 5-40%, was sedimentable. A particulate fraction obtained after isopycnic density gradient centrifugation (p = 1.187-1.241), designated fraction FA/FB, was enriched in various acid hydrolases (relative specific activities 1.33-6.24) and displayed latent phosphohydrolase activities. The density gradient distributions of this hydrolytic enzymes were compared with reference to one another and malate dehydrogenase (mitochondrial marker). From the results obtained it appears that the sedimentable acid hydrolases of Crithidia are associated with a heterogeneous population of subcellular particles. Cytochemical observations on the FA/FB fraction supported this finding and revealed the association of acid phosphatase reaction product with subcellular elements resembling multivesicular bodies.