Effect of cough technique and cryogen gas on temperatures achieved during simulated cryotherapy.

BACKGROUND: Cryotherapy is often used to treat cervical precancer in developing countries. There are different methods and cryogen gases used for cryotherapy, including the freeze-flush-freeze (cough) technique employed to minimize gas blockage. However, there is limited information to compare their effectiveness. METHODS: Using a tissue model, we compared temperature-time curves for four cryotherapy methods: uninterrupted freezing with nitrous oxide (N2O) and carbon dioxide (CO2), and two methods using a standard and extended version of the cough technique with CO2. RESULTS: Uninterrupted freezing with both N2O and CO2 produced tissue temperatures less than -20 degrees C (-40 degrees C and -30 degrees C respectively). CO2 cryotherapy procedures using the two cough techniques produced temperatures greater than -20 degrees C in the model tissue. CONCLUSION: CO2 cryotherapy using the cough technique may not achieve sufficiently low temperatures to produce the desired therapeutic effect. Other alternatives to the prevention of gas blockage should be developed.

Modelling cost-effectiveness of different vasectomy methods in India, Kenya, and Mexico.

BACKGROUND: Vasectomy is generally considered a safe and effective method of permanent contraception. The historical effectiveness of vasectomy has been questioned by recent research results indicating that the most commonly used method of vasectomy--simple ligation and excision (L and E)--appears to have a relatively high failure rate, with reported pregnancy rates as high as 4%. Updated methods such as fascial interposition (FI) and thermal cautery can lower the rate of failure but may require additional financial investments and may not be appropriate for low-resource clinics. In order to better compare the cost-effectiveness of these different vasectomy methods, we modelled the costs of different vasectomy methods using cost data collected in India, Kenya, and Mexico and effectiveness data from the latest published research. METHODS: The costs associated with providing vasectomies were determined in each country through interviews with clinic staff. Costs collected were economic, direct, programme costs of fixed vasectomy services but did not include large capital expenses or general recurrent costs for the health care facility. Estimates of the time required to provide service were gained through interviews and training costs were based on the total costs of vasectomy training programmes in each country. Effectiveness data were obtained from recent published studies and comparative cost-effectiveness was determined using cost per couple years of protection (CYP). RESULTS: In each country, the labour to provide the vasectomy and follow-up services accounts for the greatest portion of the overall cost. Because each country almost exclusively used one vasectomy method at all of the clinics included in the study, we modelled costs based on the additional material, labour, and training costs required in each country. Using a model of a robust vasectomy program, more effective methods such as FI and thermal cautery reduce the cost per CYP of a vasectomy by $0.08-$0.55. CONCLUSION: Based on the results presented, more effective methods of vasectomy--including FI, thermal cautery, and thermal cautery combined with FI--are more cost-effective than L and E alone. Analysis shows that for a programme in which a minimum of 20 clients undergo vasectomies per month, the cost per CYP is reduced in all three countries by updated vasectomy methods.

Short-term acceptability of the PATH Woman's Condom among couples at three sites.

PURPOSE: The objective of this study is to evaluate acceptability of the PATH Woman's Condom among user populations in Mexico, South Africa and Thailand. METHODS: A nonrandomized, nonblinded, nonsignificant risk study was conducted among 20 couples per site. Data were collected via structured questionnaires after the first, second and third condom uses and through in-depth interviews after all condoms were used. RESULTS: Women from all sites reported that the PATH Woman's Condom was easy and comfortable to insert, and the pouch and ring were very stable during use. Both women and men reported that the comfort and sensation of sex while using the condom was acceptable. CONCLUSIONS: The PATH Woman's Condom is easy to use, stable during use, comfortable and satisfactory during sex among users from diverse populations and cultures. The iterative user-driven product development process helped ensure that this new product addresses a wide range of user preferences.

Preliminary report of a gas conditioner to improve operational reliability of cryotherapy in developing countries.

BACKGROUND: Cryotherapy is a safe, affordable, and effective method of treatment for cervical intraepithelial neoplasia. In some low-resource settings, environmental conditions or qualities of the refrigerant gas can lead to blockage of cryotherapy equipment, terminating treatment. A prototype of a gas conditioner to prevent operational failure was designed, built, and field tested. METHODS: The prototype conditioner device consists of an expansion chamber that filters and dries the refrigerant gas. Users in Peru and Kenya reported on their experience with the prototype conditioner. In Ghana, simulated cryotherapy procedures were used to test the effects of the prototype conditioner, as well as the commonly used "cough technique." RESULTS: Anecdotal reports from field use of the device were favorable. During simulated cryotherapy, the prevalence of blockage during freezing were 0% (0/25) with the device alone, 23.3% (7/30) with the cough technique alone, 5.9% (1/17) with both, and 55.2% (16/29) with neither (Pearson's Chi square = 26.6, df = 3, p < 0.001 (comparison amongst all groups)). CONCLUSION: This prototype design of a cryotherapy gas conditioner is a potential solution for low-resource settings that are experiencing cryotherapy device malfunction.