LOW BACK PAIN IN PREGNANCY: A COMPARATIVE STUDY OF TWO PAIN-RATING SCALES Jeanette Mitchell* Donnfee Ness** *** Sandra Whitelock Summary A sample of ten pregnant Caucasian women, with an average age of 31,8 ±5 ,7 years, experiencing low back pain in the third trimester of pregnancy, rated the intensity of their pain on two commonly used pain rating scales: the horizontal visual analogue scale (VAS) and the eight-face pictorial pain scale (PPS). A mean of 3,1 ± 2 ,5 cms was found using the VAS and a mean of 5(E) was obtained on the PPS. A product-moment correlation of the two scales showed a correlation of 0,84 (p = 0,001). This implies that both pain rating scales are able to measure a similar intensity of low back pain in pregnant women. Opsomming ’n Groep tien swanger Kaukasiese vroue, met 'n gemiddelde ouder- dom van 31,8 ± 5 ,7 jaar, wat lae rugpyn gedurende die derde trimester belewe het, het dje intensiteit van hul pyn aan twee pynskale wat in algemene gebruik is, gemeet: die horisontale sigbare analoog skaal (VAS) en die agt-gesig ge'fllustreerde pyn-skaal (PPS). 'n Gemiddeld van 3,1 ± 2 ,5 cms is'Ynet die VAS en 5(E) met die PPS gevind. Met 'n produk-momeritkorrelasie van die twee skale, was ’n korrelasie van 0,84 (p = 0,001) gekry. Dit dui daarop dat altwee pynskale soortgelyke lae rugpyn-intensiteit in swanger vroue kan meet. Key Words; pregnancy, low back pain, pain-rating scales. INTRODUCTION Low back pain occurs during pregnancy, particularly in the third trimester1,3,6, Berg et alx stated that 49% of pregnant women in their study experienced such pain, while Mantle et at found 48% of their sample had low back pain. Fast et a/3 stated that 56% of the pregnant women they studied developed low back pain which began between the fifth and seventh month of pregnancy (in the third trimester). None of these studies attempted to quantify the pain. Quantification of pain can be done using a number of pain rating scales, such as the simple descriptive scale2’ ; the four-point descrip­ tive scale2; the numerical (1-10) rating scale5- the visual analogue scale2,4, and the eight-face pictorial pain scale4, . Each of these scales has advantages and disadvantages. For example, the descriptive scales are of value in literate subjects 2,4, while the pictorial scales are best used by those subjects with limited education or with language difficulties2’4,5. As part of a study of pregnant women with low back pain in the third trimester, we decided to measure the intensity of the subjects’ pain using two widely different pain rating scales. These were the horizontal visual analogue scale (VAS) and the eight-face pictorial pain scale (PPS) (after Frank et at*). The VAS has been used extensively to measure different types o f pain2,4, while the PPS has been similarly used in populations which may have found the VAS difficult to use for cultural and/or educational reasons4,5. The purpose of this study was twofold. Firstly, we proposed to assess whether a literate scale (such as the VAS) and a pictorial scale (the PPS, for example) generated comparable data in a group of educated subjects. Given the differing levels o f education in the South African population, both scales need to be used, but must be comparable. The second purpose was to assess the degree o f low back pain in pregnancy. MATERIALS AND METHOD One hundred and thirty pregnant women attending antenatal classes were interviewed to inform them o f the nature o f the study and to select a sample of subjects. Questionnaires were used to establish which of the 130 pregnant women interviewed fitted the selection criteria for the study sample. That is, all subjects had to be Caucasian, South African, English-speaking, middle-class women, all of whom had completed the secondary level of education. Each subject was experiencing low back pain in the third trimester of pregnancy only, having had no pain prior to her pregnancy. There was to be no history of musculo-skeletal conditions, and the women were to be aged 20 to 40 years. O f this population of 130 pregnant women, 21 (16,2%) were experiencing low back pain in the third trimester, 10 of whom were prepared to participate in the study. Informed consent was obtained from each of them. I---------- NO PAIN FIG 1: THE VISUAL ANALOGUE SCALE D M A c U E G F FIG 2: THE PICTORIAL PAIN SCALE (redrawn from Frank et al4) EXTREME PAIN * BSc (Physiotherapy), BSc Hons, MSc ** BSc (Physiotherapy) *** BSc (Physiotherapy) Correspondence to Jeanette Mitchell, Lecturer, Department o f Physiotherapy, University o f the Witwaiersrand Medical School, 7 York Road, Parktown, Johannesburg 2193 This study was part o f an undergraduate project completed in the Department o f Physiotherapy Physiotherapy, August 1992 Vo148 no 3 Page 33 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) .e , VP0 , e ^ ' > * V x f l^ • ^ V t o 1 US'* y e ^ If you’d like to work in the US, contact HPI. We’ve helped more physical therapists find great jobs in America than any other recruiter. Top pay, expert licensing and visa processing. Fees paid by your employer. s