[Should patients in general practice be offered a copy of their medical record?]

BACKGROUND

Is it useful for patients in general practice to have a copy of their medical record, and will this increase the quality of the record? What do patients and their doctors think about such a practice?

MATERIAL AND METHODS

Eight general practitioners participated in a study where they should ask their patients if they wanted at copy of their medical record after the consultation. The doctors were asked about what they felt about such a practice. 181 patients participated.

RESULTS

126 patients (70%) wanted to read their medical record. Among these, 118 (94%) reported that the record covered the problem they came for, 104 (83%) that it was useful to read what the doctor had written, and 96 (76%) that this practice should be more common. The doctors answered that the records became somewhat changed and longer and were more time-consuming. Most of the doctors thought that the quality of the medical record improved and that the procedure could well be standardised.

INTERPRETATION

The results indicate that many patients in general practice will find it useful to read their medical record. The study may indicate a better quality of the record when doctors are aware that the patients will have a copy.

Characteristics and health impacts of volatile organic compounds in photocopy centers

This study investigates the indoor air quality of typical photocopy centers in Taiwan to evaluate the human health risk following inhalation exposure. Both personal and area samplings were conducted at seven photocopy centers in the Tainan area from July 2002 to March 2003, which covered both summer and winter seasons in Taiwan. The benzene, toluene, ethylbenzene, xylenes, and styrene (BTEXS) measurements indicated no difference between personal and area samplings (P>0.05) and found that air conditioning improves indoor air quality. The additive factor at each photocopy center was significantly below 1.0, based on the current BTEXS permissible exposure limits in Taiwan. However, the mean benzene and styrene levels in the current study were 138 and 18 times, respectively, higher than those in another study conducted in the United States. Comparison of mass ratios of BTEXS with those of several chamber studies revealed that the photocopier is not the only volatile organic compound (VOC) source in photocopy centers. The lifetime cancer and noncancer risks for workers exposed to VOCs were also assessed. Results show that all seven centers in this study had a lifetime cancer risk exceeding 1x10(-6) (ranging from 2.5x10(-3) to 8.5x10(-5)). Regarding noncancer risk, levels of toluene, ethylbenzene, xylenes, and styrene were below the reference levels in all photocopy centers; however, the hazard indices for all still exceeded 1.0 (range 26.2-1.8) because of the high level of benzene in the photocopy centers.

Photocopies yield lower digit ratios (2D:4D) than direct finger measurements

The ratio between 2nd and 4th digit length (2D:4D) may be a negative correlate of prenatal testosterone. This possibility has led to a number of studies of 2D:4D and its relationship with sexual orientation and other sex-dependent traits. At first, 2D:4D ratio was calculated from measurements made directly on the fingers but recently a number of studies have used measurements from photocopies of the hands. Here, we compared finger lengths (2D, 3D, 4D, and 5D) and ratios obtained from these two measurement techniques. Our sample consisted of 30 homosexual men and 50 men and 70 women who were not selected for their sexual orientation. We found evidence that (1)2D:4D from photocopies tended to be lower than that from direct measurements, (2) there were differences in finger lengths such that 2D from photocopies tended to be shorter or equal in length to direct measurements, while 4D from photocopies tended to be longer or equal in length to direct measurements, (3) the sex differences in 2D:4D tended to be stronger for photocopy measurements, and (4) the pattern for length differences across 2D to 5D appeared to be different for homosexual men compared to men and women recruited without regard to sexual orientation. We conclude that there are differences in digit ratios obtained from photocopies and direct measurements, and these differences arise from length differences recorded from the different protocols. Therefore, 2D:4D ratios obtained from photocopies and direct measurements should not be combined within one study nor should they be used together in comparative studies. We suggest that finger length differences between the two techniques could result from the shapes of fat-pads at the tips of the fingers and these may be dependent on sex and sexual orientation.

A comparative study on methods of measuring mesiodistal tooth diameters for interceptive orthodontic space analysis

AIM

This study was designed to find the most reliable method of measurement of mesiodistal tooth diameter.

METHODS

Measurements were made of all erupted permanent teeth of 14 orthodontic study casts. These measurements were made directly by using A) a digital calliper, B) measuring photocopies of casts with a calliper, C) a Magiscan Image Analysis using a photocopy of the casts. Measurements derived from the two methods were compared by statistical analysis.

RESULTS

These showed that the electronic digital calliper was the most reliable method of measuring mesiodistal tooth diameter using dental study casts. The measurement of photocopies was unreliable and the image analysis method had a too high error factor.

Assessing the accuracy of caries diagnosis via radiograph

BACKGROUND

The authors conducted this study to determine if proximal caries diagnoses made using bitewing radiographic images printed on photographic paper were comparable with diagnoses made using traditional radiographic film images.

METHODS

The authors digitized 15 posterior bitewing radiographs that contained 74 carious and 127 sound unrestored proximal surfaces and printed them on photographic paper. Fourteen dentists evaluated the radiographs and two printed image formats (4 x 3 centimeters and 8 x 6 cm) for evidence of caries. The diagnostic accuracy and interobserver agreement for caries diagnoses obtained in the two printed image formats were compared with those for radiographic film images.

RESULTS

Overall, the diagnostic accuracy of printed images did not differ significantly from radiographic film images for dentinal caries. However, for caries limited to the enamel surface, a decrease in sensitivity was noted in six of the 14 observers for the smaller print images, while no significant differences in the diagnoses of enamel caries were observed among any of the observers in the enlarged print format.

CONCLUSION

This study provides evidence that printed images can be used to diagnose dental caries reliably.

CLINICAL IMPLICATIONS

The results of this study indicate that the diagnostic information obtained by viewing printed images is equivalent to that obtained by viewing standard radiographs. Size of the printed image also may be important in caries diagnosis and care must be taken to print bitewing radiographic images at a size that optimizes interpretation. Other factors that must be considered are the type of printer, printer resolution, paper quality and type of ink used. With careful consideration of printing parameters, clinicians can be assured of diagnostic quality in printed images.

An overview of radiographic film holders

OBJECTIVES

To provide an overview of radiographic film holders, from their inception in the early 1900s to present day.

METHODS

A Medline literature search was conducted for dental studies that used keywords that pertain to radiographic film holders. Hand searches of the bibliographies were also conducted. Sixty articles (dating from 1896 to 1998) that describe new or improved film holders are reviewed here.

RESULTS

From the earliest days of dental radiography, dentists attempted to standardize radiographic images and techniques. The focus of researchers in the 1950s to the 1970s was to develop a film holder that would hold the film and allow easy and predictable alignment of the X-ray tube. As research projects became more dependent on dental radiographic measurements, the focus shifted to producing reproducible radiographic images, from which highly repeatable measurements could be made.

CONCLUSION

Existing devices have strengths and weaknesses. Readily available devices are adequate for routine clinical use; however, user-friendly and patient-friendly film-holding devices that result in highly reliable and accurate measurements have yet to be introduced.

Taking a closer look

PURPOSE

This article aims to explore the value of deconstruction in the analysis of a health policy document.

DESIGN/METHODOLOGY/APPROACH

Following a brief overview of the philosophy and concepts of deconstruction, the historical and political context of the document Copying Letters to Patients: Good Practice Guidelines is clarified. Deconstructive techniques are employed to systematically analyse the document, pursuing concepts such as the identification and exploration of marginalisation within the text; analysis of figures of self-reference; the revelation of asymmetrical oppositions within the text; identification of tensions and instabilities within the text; and analysis of ways in which the text suggests a difference in emphasis from the apparent primary intention.

FINDINGS

Through utilisation of the key concepts of deconstruction, it is revealed how the policy document in question becomes freed from a passive acceptance of the words as fact, and its authority is brought into question. The masquerade of coherence and continuity within the article is dismantled and its inconsistencies and contradictions are exposed. The authors' stated attempts to prioritise the wishes and wellbeing of patients over the medical hierarchy are revealed as being subject to question and the influence of politics over health policy highlighted.

ORIGINALITY/VALUE

This article reveals how, by using deconstruction as a focus, the linguistic means by which a text exercises its power can be interrogated and the ideological assumptions underpinning its production revealed. As such a new and informative perspective is added.

A novel method for producing x-ray test objects and phantoms

A novel method for producing customized x-ray test objects and clinically realistic phantoms has been developed. Test objects can be created with a drawing software package and the digital images can be printed on a standard inkjet printer but using potassium iodide solution in place of the cartridge's ink. The reproducibility and the consistency, the limiting spatial resolution, the uniformity as well as the potassium iodide thickness per print have been evaluated. The relationship between the number of prints, grey levels and the radiation contrast was investigated and quantified. A copy of the Leeds TO10 contrast detail test object was printed and the x-ray images of the Leeds TO10 and of the printed Leeds TO10 were compared. In addition, the potential use of this method was demonstrated by reproducing a percutaneous transluminal coronary angioplasty clinical digital image. The reproducibility and consistency of this method was found to be better than 0.1%. The limiting spatial resolution of the printer using ink was found to be 3.55 1p mm(-1) but it deteriorated when the ink was replaced with potassium iodide and as the print density increases. The uniformity across the printed area was found to be satisfactory although an artefact due to the printer was present in the x-ray images. The comparison between the Leeds TO10 and the printed Leeds TO10 gave differences less than 10%. A good agreement between the clinical image and the printed clinical image was found. In conclusion, the method is a reliable, cost-effective, flexible and alternative way for producing x-ray test objects and clinically related phantoms.

Genotoxicity evaluation of individuals working with photocopying machines

Photocopying machines are a common sight in the cities of India. There is ample evidence showing that the components of toners individually or in the form of a complex mixture are genotoxic. Toxic components of the photocopiers are from their emissions, toners and extremely low frequency electromagnetic fields (ELF-EMFs). In the present study micronucleus test (MNT) on buccal epithelial cells, cytokinesis block micronucleus (CBMN) assay and chromosomal aberration analysis on peripheral blood mononuclear cells was performed on 98 workers occupationally involved in photocopying and 90 age and sex matched controls. The results showed a significant increase in the frequency of MN in buccal epithelial cells and peripheral blood lymphocytes, as well as chromosomal aberrations in the exposed as compared to the control subjects.

Peripheral Vascular Disease: Blinded Study of Dedicated Calf MR Angiography versus Standard Bolus-Chase MR Angiography and Film Hard-Copy Angiography

PURPOSE

To compare the accuracy of contrast material-enhanced three-dimensional (3D) dedicated calf magnetic resonance (MR) angiography with that of bolus-chase MR angiography, with conventional angiography as the reference standard, in patients with symptomatic peripheral vascular disease (PVD).

MATERIALS AND METHODS

Thirty men with symptomatic PVD were examined. MR angiography was performed at 1.5 T before conventional angiography. MR angiographic examination included 3D contrast-enhanced dedicated calf MR angiography and three-station bolus-chase MR angiography. Two radiologists blinded to conventional angiographic results evaluated the MR angiograms independently. Two angiographers evaluated the conventional angiograms in consensus. Calf artery segments were graded as having 50% or less stenosis, greater than 50% stenosis, or occlusion or as being nondiagnostic. Statistical analyses were performed with paired permutation testing.

RESULTS

Analyses of 472 calf segments and 420 pelvic and thigh segments were performed. Of the 472 calf segments, three and 75 segments (reader 1) and seven and 91 segments (reader 2) were graded as nondiagnostic at dedicated calf MR angiography and bolus-chase MR angiography, respectively. Differences in diagnostic grade between the two examinations were significant (P <.001), accounting for within-subject correlations, with a mean estimated difference of -17.1% (95% confidence interval [CI]: -25.8%, -8.4%). In the calf arteries, the dedicated and bolus-chase MR angiographic sequences had diagnostic accuracies, respectively, of 81.5% (reader 1) and 79.1% (reader 2) and of 67.8% (reader 1) and 63.4% (reader 2). The dedicated calf sequence was significantly more accurate than the bolus-chase sequence (P =.001). The point estimate of the difference was 14.7%, with estimated correct diagnosis rates of 80.3% and 65.6% for the dedicated calf and bolus-chase examinations, respectively (95% CI for difference: 4.0%, 25.4%). The diagnostic accuracy of bolus-chase MR angiography at the pelvis-thigh level was slightly higher when it was performed first: 81.9% (reader 1) and 83.8% (reader 2) versus 74.3% (reader 1) and 80.0% (reader 2) when it was performed last. The difference was not significant (P =.21).

CONCLUSION

Use of dedicated calf MR angiography led to significantly increased diagnostic accuracy in the calf arteries compared with standard bolus-chase MR angiography. Use of the dual-bolus technique did not jeopardize the diagnostic accuracy in the pelvic and thigh arteries.

Effect of monitor luminance and ambient light on observer performance in soft-copy reading of digital chest radiographs

PURPOSE

To examine the combined effects of monitor luminance and ambient light on observer performance for detecting abnormalities in a soft-copy interpretation of digital chest radiographs.

MATERIALS AND METHODS

A total of 254 digital chest radiographs were displayed on a high-resolution cathode ray tube monitor at three luminance levels (25, 50, and 100 foot-lamberts) under three ambient light levels (0, 50, and 460 lux). Six chest radiologists reviewed each image in nine modes of combined luminance and ambient light. The observers were allowed to adjust the window width and level of the soft-copy images. The abnormalities included nodule, pneumothorax, and interstitial disease. Observer performance was analyzed in terms of the receiver operating characteristics. The observers reported their subjective level of visual fatigue with each viewing mode. A statistical test was conducted for each of the abnormalities and for fatigue score by using repeated-measures two-way analysis of variance with an interaction.

RESULTS

The detection of nodules was the only reading that was affected by the ambient light with a statistically significant difference (P <.05). Otherwise, observer performance for detecting a nodule, pneumothorax, and interstitial disease was not significantly different in the nine-mode comparison. There was no evidence that the luminance of the monitors was related to the ambient light for any of the abnormalities. The fatigue score showed a statistically significant difference due to both the luminance and ambient light.

CONCLUSION

When adequate window width and level are applied to soft-copy images, the primary diagnosis with chest radiographs on the monitor is unlikely to be affected under low ambient light and a monitor luminance of 25 foot-lamberts or more.

Photocopier exposure and risk of sarcoidosis in African-American sibs

BACKGROUND

In a family study of sarcoidosis in African-Americans, we detected a positive association between sarcoidosis and ever working in a sales or clerical occupation. This finding, and case reports of granulomatous lung disease in patients with photocopier toner dust exposure, led us to hypothesize that sarcoidosis risk may increase as a result of photocopier exposure.

METHODS

Retrospective data on photocopier use and maintenance were collected from African-American sarcoidosis cases and their first degree relatives. The study sample consisted of 181 African-American sibships where one or more members had a history of sarcoidosis (n = 540).

RESULTS

Sarcoidosis was statistically significantly associated with ever using a photocopier (Odds Ratio [OR] = 1.74, 95% confidence interval [CI]: 1.23-2.46), and ever changing photocopier toner or carrying out photocopier maintenance (OR = 2.88, 95% CI 1.83-4.54). In a conditional logistic regression model that adjusted for age and sex, the OR associated with a sarcoidosis history and being in the highest tertile of photocopier exposure ranged from 1.83 to 2.19 depending on the exposure measure used.

CONCLUSIONS

These results suggest that photocopier toner dust may be a previously unrecognized antigen in the pathophysiology of some patients diagnosed with sarcoidosis.

Subjective image quality of digital panoramic radiographs displayed on monitor and printed on various hardcopy media

The subjective image quality of panoramic radiographs shown on a diagnostic computer monitor were compared with professional direct thermal prints and with common inkjet prints on different paper qualities. Indirect digital panoramic radiographs were obtained from 15 patients. The images were printed with a direct thermal printer in their original format. Afterwards, these were loaded in an imaging software programme (Microsoft Photo Editor) and assessed both on computer monitor and inkjet prints on transparency, glossy, satin and regular paper. Five observers assessed subjective image quality for different regions and anatomical landmarks on a 5-point rating scale. Data were statistically analysed and inter- and intra-observer performances were calculated. Best image quality was obtained with direct thermal prints, followed in descending order by panoramic images viewed on the monitor, inkjet prints on transparencies, glossy paper, satin paper and finally regular paper. The differences were significant except for monitor images versus direct thermal prints, inkjet-transparencies and inkjet-glossy images and inkjet-satin versus inkjet-glossy images. The subjective image quality of indirect digital panoramic images is different for images shown on the computer monitor and for printed images depending on both the printer and paper type used.

A comparison between direct and indirect methods available for human bite mark analysis

Comparison techniques used in bite mark analysis are many and varied, the choice of technique depending largely on personal preference. Until recently, no one technique has been shown to be better than the others, and very little research has been carried out to compare different methods. This study evaluates and compares the accuracy of direct comparisons between suspects' models and bite marks with indirect comparisons in the form of conventional traced overlays of suspects' models or a new method using photocopier-generated overlays. Artificial bite marks in pigskin were made using standardized sets of models and recorded as photographs and fingerprint powder lifts on tape. The bite mark photographs and fingerprint lifts were coded and randomized so that a blind comparison could be made with the models, traced overlays, and photocopier-generated overlays using a modified version of the American Board of Forensic Odontology Scoring (ABFO) System for Bite Marks. It was found that the photocopier-generated overlays were significantly more accurate at matching the correct bite mark to the correct models irrespective of whether the bite mark was recorded photographically or as a fingerprint lift. The photocopier-generated overlays were also found to be more sensitive at matching the correct bite marks to the correct models than the other two methods used. The modified ABFO scoring system was able to discriminate between a correct match and several incorrect matches by awarding a high score to the correct match.

Potential for reducing indoor styrene exposure from copied paper through use of low-emitting toners

Tests were conducted using 53-L dynamic chambers to determine airborne styrene emission rates over time from freshly copied paper. Copies were produced on a single photocopier using two toners manufactured for this copier but having different styrene contents. The resulting emission models were used to predict whether indoor styrene concentrations resulting from copied paper in a typical office might be significantly reduced by use of a low-emitting toner for a given copier. The styrene emissions were best represented by either a 3rd-order decay model or by a power law model having an exponent between 0.3 and 0.5 (R2 = 0.94-0.99). The two toners resulted in copied paper having significantly different styrene emissions (p < 0.01), with unit mass emissions over 1000 hr being nine times greater with the higher-emitting toner. But copied paper is predicted to produce peak indoor styrene concentrations in a typical office no more than 1% of the World Health Organization health-based guideline. Thus, for the toners considered here, indoor styrene exposures from copied paper appear to be too limited to provide incentive for switching to the lower-emitting toner. The ability to generalize these conclusions is limited by the fact that only one copier and two toners could be tested.