Validity and Utility of Four Pain Intensity Measures for Use in International Research

Background

The majority of previous research that has examined the validity of pain intensity rating scales has been conducted in western and developed countries. Research to evaluate the generalizability of previous findings in non-developed countries is necessary for identifying the scales that are most appropriate for use in international research.

Purpose

The aims of the current study were to (1) evaluate the validity and utility of four commonly used measures of pain intensity in a sample of patients with chronic pain from Thailand and (2) compare findings in the current sample with published findings from research conducted in other countries, in order to identify the measure or measures which might be most appropriate for cross-country research.

Methods

Three hundred and sixty patients with chronic pain seen in a hospital in Bangkok, Thailand, were asked to rate their current pain and average, worst, and least pain intensity in the past week using the Visual Analogue Scale (VAS), 6-point Verbal Rating Scale (VRS-6), 0–10 Numerical Rating Scale (NRS-11), and Faces Pain Scale-Revised (FPS-R). We evaluated the utility and validity of each measure by examining the (1) rates of correct responding and (2) association of each measure with a factor score representing the variance shared across measures, respectively. We also evaluated the associations between incorrect response rates and both age and education level, and then compared the findings from this sample with the findings from research conducted in other countries.

Results

The results indicated support for the validity of all measures among participants who were able to use these measures. However, there was variability in the incorrect response rates, with the VAS having the highest (45%) and the NRS-11 having the lowest (15%) incorrect response rates. The VAS was also the least preferred (9%) and the NRS-11 the most preferred (52%) scale. Education and age were significantly associated with incorrect response rates, and education level with scale preference.

Conclusion

The findings indicate that the NRS-11 has the most utility in our sample of Thai individuals with chronic pain. However, when considered in light of the findings from other countries, the results of this study suggest that the FPS-R may have the most utility for use in cross-cultural and international research. Research in additional samples in developing countries is needed to evaluate the generalizability of the current findings.

Birth control counseling for HIV seropositive pregnant women

Testing for HIV antibody at the antenatal clinic in Siriraj Hospital started on 1 July 1991. It was found that the percentage of HIV seropositive pregnant women rapidly increased from 1.2% in 1992 to 1.9% in 1993. During those 2 years, 487 seropositive women were admitted for delivery or abortion; 23.8% were adolescents and 47.0%, young adults. Prevention of HIV transmission from mother-to-baby was birth control; 95 women (19.5%) chose to abort their pregnancy. After termination of all pregnancies by abortion or delivery, 83% requested sterilization, 12.9% accepted Norplant, 1.8% the pill and only 2.3% refused anything at all. Condoms were used regularly for prevention of HIV infection by 29.4% of men although Thai men generally do not accept them for birth control. Seropositive Norplant users had more bleeding than general Norplant users but treatments were the same.

Safety evaluation of nonoxynol-9 gel in women at low risk of HIV infection

OBJECTIVE

To determine the safety of a vaginal microbicide, COL-1492, containing 52.5 mg nonoxynol-9, applied once daily for 14 days among healthy volunteers.

METHODS

A randomized, double-blind controlled trial with three arms, COL-1492 gel versus placebo gel versus no-treatment controls, was conducted. Outcomes of interest were reported genital symptoms, incidence of gynaecological signs, and incidence of genital lesions revealed by colposcopy. Participants were enrolled in four centres (Belgium, The Netherlands, and two in Thailand).

RESULTS

A total of 534 women participated in the study: 179 used COL-1492, 178 used placebo, and 177 were no-treatment controls. Study visits were scheduled 1 week prior to enrollment (day -7), day 0 (enrollment), day 8 and day 14. The most frequently reported genital symptom was vaginal discharge in both the COL-1492 and placebo groups. This appeared to be related to leakage of the product out of the vagina. The incidence of lesions associated with epithelial disruption (ulcers and abrasions) was very low (< 2%) and there was no statistically significant difference between the three groups. Of the lesions observed by colposcopy that did not involve epithelial disruption, petechial haemorrhage was the most frequently detected, with an incidence of 20.1, 9.0 and 7.3% in the COL-1492, placebo and control groups, respectively. COL-1492 users had a higher incidence of erythema (8.4 versus 2% in the other groups).

CONCLUSION

COL-1492 showed minimal toxicity when applied once daily. A Phase III trial to assess the product's effectiveness in HIV prevention is currently ongoing.

Mean platelet volume of normal pregnant women and severe preeclamptic women in Siriraj Hospital

This study only shows that MPV in severe preeclamptic women is statistically greater than in normal pregnant women. The increase in MPV occurs while there are still no changes in platelet number. MPV may be better and more sensitive than platelet number in detecting changes in platelets. This may be useful in high risk patients. The study neither reveals that increase in MPV antecedes the development of preeclampsia nor can it predict the severity of the disease. There should be further prospective studies on MPV in the future both in preeclamptic women and normal pregnant women.

Carpal tunnel syndrome during pregnancy: prevalence and blood level of pyridoxine

The prevalence of CTS in third trimester pregnant women in the study in 28 per cent. With the use of NCS it was able to detect nearly 80 per cent of them who had no symptoms or signs. There was no association between the level of vitamin B6 or B6 deficiency and CTS. Since CTS may result in a permanent disability if undiagnosed or left untreated it is essential to make an early diagnosis and treat it especially older women and those who are edematous.