Impact of faecal occult blood test screening on emergency admissions and short-term outcomes for colorectal cancer

BACKGROUND

Small studies have examined the effect of faecal occult blood test (FOBT) screening on the proportion of hospital admissions for colorectal cancer (CRC) classed as an emergency. This study aimed to examine this and short-term outcomes in persons invited for screening compared with a control group not invited.

METHODS

The invited group comprised all individuals invited between 1 April 2000 and 31 July 2007 in the Scottish arm of the UK demonstration pilot of FOBT, and subsequently diagnosed with CRC aged 50-72 years between 1 May 2000 and 31 July 2009. The controls comprised all remaining individuals in Scotland not invited for FOBT but diagnosed with CRC aged 50-72 years in the same period.

RESULTS

There were 2981 people diagnosed with CRC in the group invited for screening (58·3 per cent participated) and 9842 in the control group. Multivariable regression adjusted for sex, age, deprivation, co-morbidities, tumour site and Dukes' stage showed no difference between the groups for emergency admissions (odds ratio (OR) 0·89, 95 per cent confidence interval (c.i.) 0·77 to 1·02; P = 0·084) or length of hospital stay (LOS) (β coefficient -1·02 (95 per cent c.i. -1·05 to 1·01) days; P = 0·226). Comparing participants with controls, there were fewer emergency admissions (OR 0·59, 0·49 to 0·71; P < 0·001) and shorter LOS (β coefficient -1·06 (-1·10 to -1·02) days; P = 0·001). Short-term mortality was lower in the screened than the non-screened population (1·1 versus 2·8 per cent; P = 0·001).

CONCLUSION

People who participated in FOBT screening had fewer emergency admissions and a shorter LOS. Deprivation was associated negatively with participation, but the impact of FOBT participation on emergency admissions was independent of deprivation level. The reduction in LOS has potential to reduce financial costs.

Patterns of uptake in a biennial faecal occult blood test screening programme for colorectal cancer

AIM

The patterns of response in faecal occult blood test (FOBT) screening were studied.

METHOD

A total of 251,578 people invited three times for faecal occult blood testing were categorized according to how they responded to the invitations, as follows: YNN, NYN, NNY, NYY, YNY, YYN, YYY or NNN (Y = response; N = no response).

RESULTS

Overall, 163,038 (64.8%) responded at least once, and of those the biggest category was YYY (98,494, 60.4%). Of 1927 cancers diagnosed in the age group eligible for screening, there were 405 screen-detected cancers, 529 interval cancers and 993 cancers arising in people who had not been screened for over 2 years (i.e. falling outside the interval cancer category). In the YYY group, 79 screen-detected cancers would have been missed had the members of this group responded YNN and 65 had they responded YYN. In the YYN group, 104 screening cancers would have been missed if they had followed the YNN pattern. In most cases, the screen-detected cancers were diagnosed at the last invitation accepted, indicating that, after a diagnosis of cancer, further screening invitations were rarely accepted. Accordingly, the numbers of screen-detected and interval cancers were adjusted for likely pattern of response according to the proportion of the whole population falling into each pattern. With this adjustment, 40.9% of the cancers in the YYY group were screen detected compared with 29.3% in the YYN group and 20.7% in the YNN group (P < 0.001). Among those who responded once, twice and three times, the stage distribution of screen-detected cancers was similar, indicating that the prognosis of screen-detected cancer is unlikely to be poorer if not detected at the first screen.

CONCLUSION

This study is the first to examine patterns of response to screening invitations and confirms the importance to individuals of continuing to accept repeated screening invitations.

Negative screening colonoscopy after a positive guaiac faecal occult blood test: not a contraindication to continued screening

AIM

In guaiac faecal occult blood test (gFOBT) screening at least 50% of positive individuals will have a colonoscopy negative for colorectal neoplasia. The question of continuing screening in this group has not been addressed.

METHOD

Data on participants aged 50-69 years with a positive gFOBT result and a negative colonoscopy were followed through the biennial screening pilot conducted between 2000 and 2007 in Scotland.

RESULTS

In the first screening round, 1527 colonoscopies were negative for neoplasia. 1300 were re-invited in the second round, 905 accepted, and 157 had a positive gFOBT result, giving a positivity rate of 17.4%. Colonoscopy revealed 20 subjects with adenoma and six with invasive cancer. In the third screening round 1031 were invited for a third time and 730 accepted: 55 had a positive gFOBT test, giving a positivity rate of 7.5%. In this group, six colonoscopies revealed adenomas but there were no cancers diagnosed. In the third screening round, 108 individuals had had two positive gFOBT results and two subsequent negative colonoscopies. Eighty-four were invited for a third gFOBT, 66 accepted and 19 (25.6%) had a positive result none of whom had an adenoma or carcinoma.

CONCLUSION

These data indicate that a negative colonoscopy following a positive gFOBT is not a contraindication for further screening, although this is likely to have a low yield of neoplastic pathology after two negative colonoscopies.

The impact of population-based faecal occult blood test screening on colorectal cancer mortality: a matched cohort study

Background:

Randomised trials show reduced colorectal cancer (CRC) mortality with faecal occult blood testing (FOBT). This outcome is now examined in a routine, population-based, screening programme.

Methods:

Three biennial rounds of the UK CRC screening pilot were completed in Scotland (2000–2007) before the roll out of a national programme. All residents (50–69 years) in the three pilot Health Boards were invited for screening. They received a FOBT test by post to complete at home and return for analysis. Positive tests were followed up with colonoscopy. Controls, selected from non-pilot Health Boards, were matched by age, gender, and deprivation and assigned the invitation date of matched invitee. Follow-up was from invitation date to 31 December 2009 or date of death if earlier.

Results:

There were 379 655 people in each group (median age 55.6 years, 51.6% male). Participation was 60.6%. There were 961 (0.25%) CRC deaths in invitees, 1056 (0.28%) in controls, rate ratio (RR) 0.90 (95% confidence interval (CI) 0.83–0.99) overall and 0.73 (95% CI 0.65–0.82) for participants. Non-participants had increased CRC mortality compared with controls, RR 1.21 (95% CI 1.06–1.38).

Conclusion:

There was a 10% relative reduction in CRC mortality in a routine screening programme, rising to 27% in participants.

Interval cancers in a FOBT-based colorectal cancer population screening programme: implications for stage, gender and tumour site

BACKGROUND

Between 2000 and 2007, a demonstration pilot of biennial guaiac faecal occult blood test (GFOBT) screening was carried out in Scotland.

METHODS

Interval cancers were defined as cancers diagnosed within 2 years (ie, a complete screening round) of a negative GFOBT. The stage and outcome of the interval cancers were compared with those arising contemporaneously in the non-screened Scottish population. In addition, the gender and site distributions of the interval cancers were compared with those in the screen-detected group and the non-screened population.

RESULTS

Of the cancers diagnosed in the screened population, interval cancers comprised 31.2% in the first round, 47.7% in the second, and 58.9% in the third, although this was due to a decline in the numbers of screen-detected cancers rather than an increase in interval cancers. There were no consistent differences in the stage distribution of interval cancers and cancers from the non-screened population, and, in all three rounds, both overall and cancer-specific survival were significantly better for patients diagnosed with interval cancers (p<0.01). The percentage of cancers arising in women was significantly higher in the interval cancer group (50.2%) than in either the screen-detected group (35.3%, p<0.001) or the non-screened group (40.6%, p<0.001). In addition, the proportion of both right-sided and rectal cancers was significantly higher in the interval cancer group than in either the screen-detected (p<0.001) or non-screened (p<0.004) groups.

CONCLUSIONS

Although GFOBT screening is associated with substantial interval cancer rates that increase with screening round, the absolute numbers do not. Interval cancers are associated with a better prognosis than cancers arising in a non-screened population, and GFOBT appears to preferentially detect cancers in men and the left side of the colon at the expense of cancers in women and in the right colon and rectum.

Effect of gender, age and deprivation on key performance indicators in a FOBT-based colorectal screening programme

OBJECTIVES

To assess the effect of gender, age and deprivation on key performance indicators in a colorectal cancer screening programme.

SETTING

Between March 2000 and May 2006 a demonstration pilot of biennial guaiac faecal occult blood test (gFOBT) colorectal screening was carried out in North-East Scotland for all individuals aged 50-69 years.

METHODS

The relevant populations were subdivided, by gender, into four age groups and into five deprivation categories according to the Scottish Index of Multiple Deprivation (SIMD), and key performance indicators analysed within these groups.

RESULTS

In all rounds, uptake of the gFOBT increased with age (P < 0.001), decreased with increasing deprivation in both genders (P < 0.001), and was consistently higher in women than in men in all age and all SIMD groups. In addition, increasing deprivation was negatively associated with uptake of colonoscopy in men with a positive gFOBT (P < 0.001) although this effect was not observed in women. Positivity rates increased with age (P < 0.001) and increasing deprivation (P < 0.001) in both genders in all rounds, although they were higher in men than in women for all age and SIMD categories. Cancer detection rates increased with age (P < 0.001), were higher in men than in women in all age and SIMD categories, but were not consistently related to deprivation. In both genders, the positive predictive value (PPV) for cancer increased with age (P < 0.001) and decreased with increasing deprivation (P < 0.001) in all rounds and was consistently higher in men than in women in all age and SIMD categories.

CONCLUSIONS

In this population-based colorectal screening programme gender, age, and deprivation had marked effects on key performance indicators, and this has implications both for the evaluation of screening programmes and for strategies designed to reduce inequalities.

Effect of repeated invitations on uptake of colorectal cancer screening using faecal occult blood testing: analysis of prevalence and incidence screening

OBJECTIVE

To analyse the effects of prevalence and incidence screening on uptake and detection of cancer in an ongoing, dynamic programme for colorectal screening using faecal occult blood testing.

DESIGN

Analysis of prevalence and incidence screening.

SETTING

Three rounds of biennial colorectal screening using the guaiac faecal occult blood test in east and north east Scotland, March 2000 to May 2007.

PARTICIPANTS

Adults aged 50-69.

MAIN OUTCOME MEASURES

Uptake of screening, test positivity (percentage of those invited who returned a test that was positive and triggered an invitation for colonoscopy), positive predictive value, and stage of cancer.

RESULTS

Of 510 990 screening episodes in all three rounds, 248 998 (48.7%) were for prevalence, 163 483 (32.0%) were for first incidence, and 98 509 (19.3%) were for second incidence. Uptake of a first invitation for prevalence screening was 53% and for a second and third invitation was 15% and 12%. In the cohort invited for the first round, uptake of prevalence screening rose from 55% in the first round to 63% in the third. The uptake of first incidence screening on a first invitation was 54% and on a second invitation was 86% and on a first invitation for second incidence screening was 46%. The positivity rate in prevalence screening was 1.9% and the uptake of colonoscopy was 87%. The corresponding values for a first incidence screen were 1.7% and 90% and for a second incidence screen were 1.1% and 94.5%. The positive predictive value of a positive faecal occult blood test result for cancer was 11.0% for prevalence screening, 6.5% for the first incidence screen, and 7.5% for the second incidence screen. The corresponding values for the positive predictive value for adenoma were 35.5%, 29.4%, and 26.7%. The proportion of cancers at stage I dropped from 46.5% for prevalence screening to 41% for first incidence screening and 35% for second incidence screening.

CONCLUSIONS

Repeat invitations to those who do not take up the offer of screening increases the number of those who accept, for both prevalence screening and incidence screening. Although the positive predictive value for both cancer and adenomas fell between the prevalence screen and the first incidence screen, they did not fall between the first and second incidence screens. The deterioration in cancer stage from prevalence to incidence screening suggests that some cancers picked up at incidence screening may have been missed on prevalence screening, but the stage distribution is still favourable. These data vindicate the policies of continuing to offer screening to those who fail to participate and continuing to offer biennial screening to those who have accepted previous offers.

Results from the first three rounds of the Scottish demonstration pilot of FOBT screening for colorectal cancer

OBJECTIVES

To assess the effects of the first three rounds of a pilot colorectal screening programme based on guaiac faecal occult blood testing (gFOBT) and their implications for a national population-based programme.

METHODS

A demonstration pilot programme was conducted in three Scottish NHS Boards. Residents aged between 50 and 69 years registered on the Community Health Index were included in the study.

RESULTS

In the first round, the uptake was 55.0%, the positivity rate was 2.07% and the cancer detection rate was 2.1/1000 screened. In the second round, these were 53.0%, 1.90% and 1.2/1000, respectively, and in the third round, 55.3%, 1.16% and 0.7/1000, respectively. In the first round, the positive predictive value of the gFOBT was 12.0% for cancer and 36.5% for adenoma; these fell to 7.0% and 30.3% in the second round and were maintained at 7.5% and 29.1% in the third round. The percentage of screen-detected cancers diagnosed at Dukes' stage A was 49.2% in the first round, 40.1% in the second round and 36.3% in the third round.

CONCLUSIONS

These results are compatible with those of previous randomised trials done in research settings, demonstrating that population-based colorectal cancer screening is feasible in Scotland and should lead to a comparable reduction in disease-specific mortality.

No difference in the association between birth weight and total cholesterol for males and females. A SHARP (Scottish Heart and Arterial Disease Risk Prevention) study

We carried out a cohort study in a relatively young healthy working population to assess any difference between males and females in the association between birth weight and adult total cholesterol. Perinatal data came from the Walker database of babies born between 1952 and 1966 in Dundee, Scotland. This was record-linked to information from the SHARP (Scottish Heart and Arterial Risk Prevention) cohort who had undergone a cardiovascular risk screening between 1991 and 1993. There were 1158 individuals (56% male, mean age 32.1 years). For both males and females there was no association between birth weight and cholesterol either unadjusted or after adjustment for BMI and other potential confounders: B = -0.11 (95% CI -0.03, 0.04) for males, B = -0.15 (95% CI -0.31, 0.01) for females. All individuals together showed a slight decrease in cholesterol for 1 kg increase in birth weight but only after adjustment for BMI: B = -0.13 (95% CI -0.24, -0.01). These results suggest no difference in the relationship between birth weight and total cholesterol for males and females.

Pre-eclampsia and the later development of type 2 diabetes in mothers and their children: an intergenerational study from the Walker cohort

AIMS/HYPOTHESIS

Studies have shown a relationship between pre-eclampsia and later coronary artery disease. This study investigated whether there is a relationship between pre-eclampsia and the development of type 2 diabetes in mothers and their babies and how this is affected by infant birthweight.

SUBJECTS AND METHODS

This was an intergenerational cohort study. The study population comprised 7,187 mothers who gave birth and 8,648 babies who were born in Dundee, Scotland between 1952 and 1958. Their later diabetic status was defined from 1980 to 2003 by linkage to population-based datasets.

RESULTS

There were 810 (11.3%) mothers with pre-eclampsia and 745 (10.4%) who subsequently developed type 2 diabetes. Logistic regression showed an increased risk of developing type 2 diabetes for mothers with pre-eclampsia, unadjusted odds ratio (OR) 1.37 (95% CI 1.10-1.71), p=0.005. This relationship persisted after adjustment for infant birthweight, OR 1.40 (95% CI 1.12-1.75), p=0.003. Of the babies born between 1952 and 1958, 221 (2.6%) had developed type 2 diabetes, 137 of them male (2.9% of male subjects in study population) and 84 female (2.2% of female subjects). The relationship between pre-eclampsia in the mother and the risk of type 2 diabetes in the offspring did not reach statistical significance, OR 1.38 (95% CI 0.90-2.10). Babies with birthweight in the lowest quintile (adjusted for sex, gestation and birth order) had an increased risk of developing type 2 diabetes, OR for lowest quintile vs highest quintile 1.84 (95% CI 1.24-2.72), p=0.002.

CONCLUSIONS/INTERPRETATION

Pre-eclampsia is associated with increased risk of developing type 2 diabetes in the mother, but birthweight is a more important determinant of future risk for the offspring.

Record-linkage methodology for prescribing research

Record-linkage refers to the linking together of data relating to the same individual from separate source files. In this paper, we discuss ways in which the technique can enhance observational prescribing research in large populations. We draw upon the work of the Medicines Monitoring Unit (MEMO), University of Dundee, to illustrate its contribution to prescribing research.

Impaired bioavailability of vitamin A in adults and children with persistent diarrhoea in Zambia

BACKGROUND

We have previously demonstrated a strong relationship between low serum retinol concentration and mortality in Zambian AIDS patients with diarrhoea, but were unable to detect any benefit from oral micronutrient supplementation.

AIM

To test the hypothesis that this is related to impaired availability of vitamin A, we analysed serum retinol concentration changes over 6 h following oral mega-dose therapy (60, 120 or 180 mg retinol).

METHODS

Twenty-four men without diarrhoea, 15 adults with persistent diarrhoea and 11 children (six girls, five boys) with persistent diarrhoea were studied.

RESULTS

Men with persistent diarrhoea had lower baseline serum retinol concentrations (median 0.39 micromol/L, interquartile range 0.21-0.56) than controls (median 1.16 micromol/L, interquartile range 0.84-1.47; P=0.0003). After 60 mg retinol, the rise in serum retinol in HIV seropositive controls (median 0.63 micromol/L, interquartile range 0.35-0.77) did not differ significantly from that observed in HIV seronegative controls (median 0.35 micromol/L, interquartile range - 0.04-0.56; P=0.20). Increasing the dose to 120 mg or 180 mg retinol did not enhance the increase in serum retinol concentration. The increase in serum retinol was less in adults with persistent diarrhoea (median 0.25 micromol/L, interquartile range 0.04-0.35) and in children (median 0.11 micromol/L, interquartile range 0.04-0.46) than in men without diarrhoea (median 0.44 micromol/L, interquartile range 0.26-0.74; P=0.03). Adults and children with diarrhoea had greater losses of retinol in urine over a 24-h period than controls, but less than 1% of the ingested dose was excreted.

CONCLUSIONS

These results suggest that persistent diarrhoea in this population is associated with reduced bioavailability of retinol. Further work is required to determine the metabolic fate of therapeutic doses of retinol and to determine appropriate replacement strategies for HIV infected individuals.

Longevity of fixed partial dentures

STATEMENT OF PROBLEM

The anticipated length of service and reasons for replacement of fixed partial dentures (FPDs) are a frequent inquiry by patients. Previous reports have provided limited information on material and techniques used in restoration or standards in evaluations of restorations at delivery.

PURPOSE

This study determined the reasons for failure and length of service for FPDs delivered with specific clinical, radiographic, and laboratory procedures.

METHODS

A clinical and retrospective chart review was conducted on all patients with FPDs who were treated in the prosthodontic clinic at the University of Iowa Hospital for routine dental hygiene recalls during a 6-month period. Fifty patients were examined with a total of 89 FPDs. Of the 89 FPDs, 13, or 15%, were identified as failures or had been replaced because of failure. Dental caries was the most frequent cause of failure (38%), followed by periapical involvements (15%), perforated occlusal surfaces (15%), fractured post and cores (8%), defective margins (8%), fractured teeth (7%), and porcelain failures (8%). The mean length of service for failed FPDs ranged from 16.0 years, because of failure from dental caries, to 4.1 years, because of a fractured post and core.

RESULTS

A linear regression model of years in service against number of failed FPDs indicated that the number of years in service provided no information on predictability of failure for FPDs.

CONCLUSIONS

This study supported previous reports of dental caries as the primary cause for failure of FPDs, but specific radiographic, clinical, and laboratory procedures can increase the length of service of these restorations.

The prevalence of symptoms of irritable bowel syndrome among acute psychiatric inpatients with an affective diagnosis

An interview study of 87 inpatients with affective diagnoses, according to the International Classification of Diseases (9th Edition), yielded a prevalence of irritable bowel syndrome (IBS) of 39.7%, approximately twice that found in the general population. The IBS symptoms almost invariably preceded the onset of the affective disorder, but were exacerbated by it. The consultation rate for bowel symptoms (41.9%) was greater than that in the general population. In this study, 69.2% of consulters and 55.5% of nonconsulters had experienced an exacerbation of their IBS symptoms since the onset of their emotional disorder. These findings suggest that such disorders may influence the subjective severity of IBS and also consultation behavior, but do not play a major part in the etiology of the gastrointestinal symptoms.

Abnormal illness attitudes in patients with irritable bowel syndrome

The Illness Attitudes Scales (IAS) and the Beck Depression Inventory (BDI) were administered to 40 patients with irritable bowel syndrome (IBS) and these were compared with 35 patients with organic gastrointestinal (GI) disease, 37 depressed patients, and 40 healthy volunteers. The BDI score was found to be greater in the IBS patients than in either the patients with organic disease or healthy subjects. All the patient groups had abnormal IAS scores compared with the healthy group, but these were most marked among the IBS patients with elevated scores on six out of the eight subscales. Three of these were specific to the IBS patients: bodily preoccupation, hypochondriacal beliefs and disease phobia. The results of this study indicate that clinical IBS is associated with abnormal illness attitudes which are not simply a reflection of either an associated depression or of experiencing physical symptoms.

Abnormal REM sleep in the irritable bowel syndrome

Motor abnormalities of the small bowel that occur only during the waking state have been reported in the irritable bowel syndrome (IBS), suggesting that central nervous system arousal is a necessary condition for expression of the disorder and that it may reflect inappropriate brain-gut interaction. This possible relationship was explored further by synchronous polysomnography and recording of upper small bowel motility in six healthy subjects and six patients with IBS. During sleep, there was no difference in the patterns of intestinal motility between the two groups. There was no difference between the rapid eye movement (REM) latency or number of REM episodes, but the proportion of REM sleep was markedly increased (36.5% +/- 5.7% vs. 18.2% +/- 5.7%; P less than 0.01) in the IBS group, although the duration of sleep was similar (468 +/- 13 minutes in IBS vs. 444 +/- 10 minutes in controls; P greater than 0.1). Sleep apnea was detected in three of six patients with IBS but was not seen in controls. The data are consistent with the model of IBS as a disorder of brain-gut interaction.

Prospective, controlled, randomized trial of naloxone infusion in early hyperdynamic septic shock

To determine whether naloxone infusion is efficacious in severe hyperdynamic septic shock, we conducted a prospective study of 22 patients randomly assigned to a naloxone or placebo group. Patients were treated 12 +/- 2 h (SEM) after the onset of shock, with a mean arterial pressure (MAP) of 63 +/- 3 mm Hg. All patients had clinical evidence of an infectious process and required dopamine 20 +/- 2 micrograms/kg.min. Five (46%) of 11 patients in the naloxone group and one (9%) of the other 11 patients in the placebo group responded clinically. The MAP among the five responders increased from 62 +/- 5 to 89 +/- 4 mm Hg within 20 min of naloxone treatment (p less than .01). This favorable hemodynamic response was sustained throughout the patients' clinical course. In contrast, the MAP did not change significantly in the nonresponders who received naloxone, nor did it change in the placebo group. More patients in the naloxone group than in the placebo group received steroids concurrently. Survival rate was 100% in those who responded to naloxone clinically. However, overall survival rate in each group was essentially the same. No adverse effects were observed, except for mild agitation in some of the patients receiving naloxone. We conclude that naloxone infusion is clinically efficacious in improving the hemodynamic profile of a subgroup of patients with severe early hyperdynamic septic shock, but does not appear to improve the overall survival rate.