Summary of results: additional information
| Study and country | N at baseline | Intervention and outcome measure | Level at baseline | Level postintervention | Effect on outcome | |
|---|---|---|---|---|---|---|
| Randomised controlled study designs | ||||||
| Baker et al23 UK | Practices: 17 (I) 16 (C) | Intervention(s): G+FB Measure(s): median (IQR) number of TFTs per 1000 registered patients | 17.4 (8.0, 39.5) (I) 22.7 (10.4, 30.9) (C) | 19.8 (6.2, 42.3) (I) at 6 months 19.5 (10.3, 31.1) (C) at 6 months 17.7 (6.6, 43.3) (I) at 9 months 17.3 (10.1, 34.0) (C) at 9 months 13.2 (6.3, 35.7) (I) at 12 months 20.9 (13.3, 35.3) (C) at 12 months |
| |
| Daucourt et al,25 France | Hospital wards:
| Intervention(s): PMC, TRF, PMC+TRF Measure(s): GCR | NA | 77.9% (95% CI 68.9% to 87.0%) (MPC+TRF) 82.6% (95% CI 73.1% to 92.1%) (TRF) 73.4% (95% CI 56.7% to 90.1%) (MPC) 62.0% (95% CI 47.7% to 76.4%) (C) |
| |
| Thomas et al,10 UK | Practices:
| Intervention(s): FB, R, FB+R Measure(s): median (IQR) TFT requests per 10 000 patients per practice | 750 (515–1329) (C) 829 (476–1412) (FB) 961 (476–1338) (R) 891 (392–1277) (FB+R) | 795 (552–1466) (C) 802 (432–1359) (FB) 891 (490–1250) (R) 800 (287–1077) (FB+R) |
| |
| Tierney et al,35 USA | Scheduled visits:
| Intervention(s): display of computer-generated probability estimates Measure(s): charges per scheduled visit (in USA$) | NA | 1.25 (C) 1.12 (I) |
| |
| Non-randomised controlled study designs | ||||||
| Berwick and Coltin,17 USA | 35 internists and 30 adult nurses at 3 centres (total number of visits not given) | Intervention(s): TSE, FBC and FBY Measure(s): per cent change in the number of TT4 ordered per 100 encounters and the CV of test ordering rates | TT4 tests per 100 encounters:
| Change: | CV: |
|
| C: +1.7% | +15.7% | |||||
| TSE: −15.9% | +0.5% | |||||
| FBC: −12.1% | −23.6 | |||||
| FBY: +34.0% | −28.2 | |||||
| Gama et al,18 UK | Outpatient visits:
| Intervention(s): FB Measure(s): TFTs per outpatient visit (mean, range) | 0.17 (0.12–0.22) (I) 0.05 (0.04–0.06) (C) | 0.13 (0.11–0.17) (I) 0.06 (0.05–0.08) (C) |
| |
| Schectman et al,33 USA | 1425 patients, 30 clinicians (group distribution not given) | Intervention(s): R and R+FB Measure(s): Compliance Mean (SE) number of TFTs ordered per patient | 68% (R) 65% (R+FB) 1.68 (0.04) | 81% (R) at 6 months 77% (R) at 12 months 64% (R+FB) at 6 months 80% (R+FB) at 12 months 1.37 (0.03) at 2/12 (following EM) 1.32 (0.05) at 6-month follow-up 1.49 (0.04) at 1-year follow-up |
| |
| Tomlin et al,36 New Zealand | GPs:
|
| 223.6 (I) 33.8 (C) 144.2 (I) 29.1 (C) 41.6 (I) 11.0 (I) NR 2.4:1 7.1:1 NR | 215.2 (I) 32.0 (C) 80.7 (I) 25.3 (C) 26.6 (I) 9.4 (C) 21% decrease (I) NR (C) 3.0:1 8.5:1 −19.8% (I) −9.5% (C) | TSH showed small decrease (4%, p<0.01) in the I group and no change in the C group (p<0.11). FT4 and FT3 decreased by 44.1% and 36.0%, respectively (p<0.01) in the I group and 13.1% and 14.6%, respectively, in the C group (p<0.01). In the I group, the proportion of TSH as the sole test ordered increased from 43.2% to 65.2% (p<0.001). Ratios of TSH to FT4 increased from 2.4:1 to 3.0:1 and TSH to FT3 from 7.7:1 to 8.5:1. Simultaneous testing of TSH and FT4 and/or FT3 decreased by 41.1% and there was a decrease in the net TFT expenditure (no p values given). | |
| Wong et al,42 USA | NR | Intervention(s): G+TRF Measure(s): tests per month | Intervention tests (months to intervention):* T4 (RIA) and T3RU:
CK:
| Intervention tests (months after intervention was introduced):* T4 (RIA) and T3RU:
CK:
| Distributing guidelines through a bulletin alone failed to produce effect but in combination with request form redesign it led to restructuring of test ordering patterns with decrease of ‘complete’ thyroid panel and increase of hyperthyroid and hypothyroid panels and thyroid function screen. No changes in T4 (RIA) and T3RU but the number of T3 (RIA) and TSH tests ordered per month fell on the average to 38% and 61%, respectively, of the mean monthly rates at which these tests had been ordered in the preceding 18 months. No changes were observed in the ordering of the control tests. Statistical significance of the above results is NR. Not all data presented here! | |
| Interrupted time series | ||||||
| Horn et al,45 | Average monthly orders per 1000 patient visits (TSH):
| Intervention: display of cost of tests being ordered Measure(s): comparison of change-in-slope of the monthly ordering rates between intervention and control physicians for 12 months preintervention and 6 months postintervention | Per cent change in monthly order rates (TSH, preintervention):
| Per cent change in monthly order rates (TSH, postntervention):
| The difference in the rate of change preintervention to postintervention was 0.7% decrease in the I group and 0.3% increase in the C group; none of these results was significant at p value <0.002 (2-sided Bonferroni-adjusted p value). Across all 27 evaluated tests, a statistically significant modest decrease in ordering rates of intervention physicians compared with control physicians was observed in 5 tests. | |
| Van Walraven et al,39 Canada | NR | Intervention(s): G+CFP; G+TRF Measure(s): avoided tests, utilisation rate and cost | 1 July 1991:
| G+CFP:
| G+CFP led to 96% decrease in the TT4 utilisation (p=0.02) and decrease in T3RU. Guidelines plus removing TSH ‘tick box’ from the request form resulted in 12% decrease in TSH utilisation (p=0.03). All interventions together resulted in a decrease of 626 098 tests, which saved $2 010 400, including $29 664 in the final year. | |
| Before and after study designs | ||||||
| Adlan et al,22 UK | Admissions:
| Intervention(s): G Measure(s): proportion of admitted patients offered TFTs | 53.8% (857 out of 1593) | 21.7% (255 out of 1176) | Significant reduction (32.1%, p<0.001) in the proportion of admitted patients offered TFTs | |
| Chu et al,24 Australia | ED visits:
| Intervention(s): G Measure(s): mean number of TFTs ordered per 100 ED visits | 2.2 (20-week preintervention period) | 1.6 (20-week postintervention period) | Significant reduction in the mean number of TFTs (0.6 tests per 100 ED presentations, p=0.001) The mean number of all blood tests ordered per 100 ED presentations fell by 19% (p=0.001) and the mean cost fell by 17% (p=0.001). | |
| Cipullo and Mostoufizadeh,39 USA | NA | Intervention(s): G Measure(s): mean tests utilisation (T3 per discharge) | 0.006 (1 year before) | 0.005 (1 year after) | The number of T3 uptake per discharge decreased by 17%. Most of the other targeted tests also showed decline in utilisation. Statistical significance NR. | |
| Dowling et al,26 USA | Patient visits: 10 961 (pre), 6606 (post),3024 (at 5 months follow-up) | Intervention(s): E+FB Measure(s): proportion of indicated TSH (out of all TSHs performed) Rate of TSHs ordered per patient visit (total number of TSHs and visits) Rate of indicated TSH per visit Rate of non-indicated TSHs per visit | 28% (25 of 90) 1 per 122 (90 in 10 961) 1 per 438 1 per 169 | 65% (15 of 23) 43% (9 of 21) (at 5 months follow-up) 1 per 287 (23 in 6 606) 1 per 178 (21 in 3 024) (at 5 months follow-up) 1 per 440 1 per 336 (at 5 months follow-up) 1 per 826 1 per 252 (at 5 months follow-up) | The proportion of indicated TSHs increased significantly (p<0.001) while TSHs per patient visit decreased significantly (p<0.0001) in the intervention period but both showed some decline at 5 months follow-up. The rate of indicated TSHs per visit did not change significantly while the rate of non-indicated TSHs per visit decreased drastically in the intervention period but increased again at follow-up. Data for the control test, CBC with differential, is not shown here but the rate of ordering showed steady decline even in the follow-up and the rates of ordering both indicated and non-indicated CBCs decreased at the end of the intervention, although the statistical significance of these results was NR. | |
| Emerson and Emerson,27 USA | Unclear | Intervention(s): TRF Measure(s): number of tests/panels ordered preintervention to postintervention | TSH: 5300* FT4: 750 TT4: 1700 TT3: 800 FTI/T3RU: 900 TFT cascade: NA Combined TSH and cascade: 5250 | TSH: 3000* FT4: 1450 TT4: 200 TT3: 500 FTI/T3RU: 100 TFT cascade: 1700 Combined TSH and cascade: 4750 | TFT testing decreased significantly (p<0.01) with a shift towards FT4 and thyroid cascade. Across all tests, the total number of tests remained the same (due to an increase in the number of patients) but the number of tests per patient visit showed significant decrease (p<0.01). | |
| Feldkamp and Carey,28 USA | Sequential TFT requests: 1000 (pre) 463 (post, 1 year) 625 (post, 3 years) | Intervention(s): G Measure(s): percentage of different TFTs and combinations: | Prealgorithm: | 1 year | 2 years | ‘TSH only’ and DRTSH accounted for 92.4% of all TFTs 3 years after the introduction of the algorithm. The other combinations gradually decreased. However, the statistical significance of these results is NR. |
| TFT only | 33.3% | 44.8% | 32.2% | |||
| DRTSH algorithm | – | 24.4% | 60.2% | |||
| TSH+TT4+T3RU | 16.6% | 3.9% | 1.3% | |||
| TT4 only | 10.0% | 4.8% | 0.8% | |||
| TT4+T3RU | 6.8% | 2.8% | 1.1% | |||
| Others (including TT3) | – | – | 3.0% | |||
| TFTs per 1000 patients: | Prealgorithm: | Postalgorithm: DRTSH: | Tests/1000 | |||
| TSH | 832 | 982 | 1000 | |||
| TT4 | 667 | 216 | 202 | |||
| T3RU | 234 | 159 | 202 | |||
| Total | 1 733 | 1359 | 1404 | |||
| Difference | – | 374 | 329 | |||
| Grivell et al,29 Australia | NR | Intervention(s): FB Measure(s): ratio of thyroxin requests postintervention to preintervention | NA | 1.20 | Thyroxin requests in the postintervention period were 1.2 times the requests in the preintervention period but the statistical significance of this result was NR. | |
| Hardwick et al,44 Canada | NR | Intervention(s): G+CFP Measure(s): proportion (number) of different TFTs: | 1974/75 | 1976/77 | 1978/79 | Overall decline from baseline to 3 years postintervention (1978/79) with shift towards TT4 which accounted for 80.4% of all TFT investigations in the last period. Expenditure also decreased to 34% of the expected charges by the end of the study period. The statistical significance of these results was NR. |
| TT3 | 21.8% (29 004) | 19.0% (35 101) | 4.7% (7502) | |||
| TT4 | 51.8% (68 912) | 50.8% (93 988) | 80.4% (128 343) | |||
| ETR | 26.4% (35 183) | 30.2% (55 798) | 14.9% (23 703) | |||
| Total | 100% (133 099) | 100% (184 887) | 100% (159 548) | |||
| 1975/76 | 1977/78 | |||||
| TT3 | 20.4% (33 334) | 11.8% (19 255) | ||||
| TT4 | 49.6% (81 004) | 62.3% (101 805) | ||||
| ETR | 29.8% (48 832) | 25.9% (42 346) | ||||
| Total | 100% (163 170) | 100% (163 406) | ||||
| Horn et al,45 | Physicians: 153 (I) 62 (C) | Intervention(s): Display of cost of tests being ordered (computer-based ordering system) Measure(s): difference in per cent change in monthly orders between I and C group (orders per 1000 patient visits) | Baseline average monthly order rate (orders per 1000 visits):
| Per cent change in monthly order rate:
| Difference:
| Monthly order rates for TSH decreased slightly in the I group and increased in the C group but the difference was not statistically significant (p=0.04; because 27 tests were analysed, the study used a 2-sided Bonferroni-adjusted p value of <0.002 to determine statistical significance). |
| Larsson et al,30 Sweden | 19 primary care centres | Intervention(s): E Measure(s): mean ratios of the requests for related tests: | 1996 | 1997 | Significant decrease in TT3/TSH (difference between mean ratios 0.073, SD=0.089, p=0.0012) and non-significant decrease in FT4/TSH (difference 0.032, SD=0.116, p=0.13). As recommended, the ratio of TSH to all TFTs increase significantly (difference −0.017, SD=0.041, p=0.048). | |
| TT3/TSH | 0.129 | 0.056 | ||||
| FT4/TSH | 0.333 | 0.301 | ||||
| TSH/total number of TFTs | 0.124 | 0.141 | ||||
| Mindemarkand Larsson31 (follow-up of Larsson 1999) | Median ratios: | 1997 | 2004 | 7 years after the intervention TT3/TSH and (TT4+FT4)/TSH were not significantly different from those at the end of the original study period, thus showing no decay in the intervention's effect. However, THS/all TFTs showed slight decrease (difference −0.043) which was statistically significant (p<0.05). Most of the other tests’ ratios also remained stable. | ||
| TT3/TSH | 0.029 | 0.022 | ||||
| (TT4+FT4)/TSH | 0.273 | 0.237 | ||||
| TSH/all TFTs | 0.115 | 0.072 | ||||
| Nightingale et al,32 UK | Number of patients: 654 (before) 833 (after) | Intervention(s): PMS+E+FB Measure(s): change in compliance | 55%* | 85%* | Compliance of TSH requests increased but results are given only as a graph and the statistical significance is NR. Across all tests, the total number of tests requested per patient day declined by 17% (p<0.001). | |
| Rhyne and Gehlbach,43 Canada | NR | Intervention(s): G+E Measure(s):
| October to December 1976 1.00 January to March 1977 Approximately 1.10 45% 29% | June to August 1977 Approximately 0.70 September to November 1977 Approximately 1.00 53% 19% | Significant decrease in the number of TFP ordered per encounter in the 3 months after the intervention (p<0.05) but return to baseline in the following 3 months. Results given only as a graph. The proportion of FTP for ‘high indications’ increased and that for ‘low indications’ decreased but was not statistically significant (p<0.05). Senior residents decreased their TFP ordering rate while that of junior residents increased (p<0.05). | |
| Schectman et al,33 USA | 1425 patients, 30 clinicians (group distribution not given) | Intervention(s): EM Measure(s): compliance rate Mean (SE) number of TFTs ordered per patient | 35% 1.68 (0.04) | 67% at 2 months (following EM) 1.37 (0.03) at 2 months (following EM) 1.49 (0.04) at 1 year follow-up |
| |
| Stuart et al,34 Australia | NR; annual census of 42 500 patients | Intervention(s): E+G+FB Measure(s): mean cost of TFT (in $A) per patient | 0.426 | 0.047 | TFT ordering decreased by 89% and showed a significant decrease in cost per patient (−89% difference (95% CI −55% to −123%; p<0.001). Across all tests, there was 40% decrease in the ordering of tests with test utilisation falling from a mean of $39.32/patient to $23.72/patient (p<0.001). Tests not allowed to be ordered for ED patients, such as TFT, showed the greatest decrease. The effect was sustained at 18 months follow-up. | |
| Toubert et al,37 France | 800-bed hospital with annual census of 25 266 inpatients and 242 013 outpatients | Intervention(s): G+R Measure(s): number of TFTs: | 1996 | 1997 | 1998 | A substantial decrease in the total number of TFTs mainly due to a decrease in the number of FT3 and FT4; a decrease in the relative proportion of FT3. Single TSH order forms increased from 23% to 50%, while TSH+FT4+FT3 decreased. The statistical significance of these results was NR. The percentage of appropriate tests increased from 42.5% (95%CI 39.9% to 45.1%) in 1996 to 72.4% (95%CI 69.8% to 75%) in 1997 (p<0.0001) but there was some decrease in 1998 (no p value given). (Data for thyroid antibodies is not presented here.) |
| Total TSH tests | 1329 | 1119 | 1062 | |||
| Total FT4 tests | 1011 | 535 | 539 | |||
| Total FT3 tests | 715 | 247 | 226 | |||
| Total number of TFTs | 3145 | 1901 | 1827 | |||
| Patterns: | ||||||
| Single TSH | 305 | 563 | 512 | |||
| TSH+FT4 | 319 | 313 | 333 | |||
| TSH+FT3 | 23 | 25 | 20 | |||
| TSH+FT4+FT3 | 682 | 218 | 197 | |||
| FT4+FT3 | 10 | 4 | 9 | |||
| All TFT request forms | 1339 | 1123 | 1071 | |||
| Appropriateness: | 42.5% | 72.4% | 70.7% | |||
| van Gend et al,38 The Netherlands | NR | Intervention(s): TRF+FB Measure(s): ratio of FT4 (removed from) to TSH (left on the request form) | 1992 0.96 (2498:2608) | 1993 0.31 (1180:3747) 1994 0.28 (1436:5040) | There was a decrease in the FT4:TSH ratio indicating that the intervention had impact on test ordering patterns but the statistical significance of the results was NR. | |
| Vidal-Trécan et al,40 France | June 1995: all TFTs: 27 945 | Intervention(s): E+G+TRF Measure(s): number (%) of TFTs | June 1995 | June 1998 | 11% decrease in the total number of TFTs even though the number of admissions increased by 2% and the number of outpatient visits by 6%. The proportion of FT4 tests remained the same (33%); the proportion of FT3 measurements decreased by 6% and the proportion of TSH tests increased. The statistical significance of the results was NR. | |
| Total TFTs | 100% (27 945) | 88.7% (24 794) | ||||
| FT3 | 20% (5491) | 14% (3534 of 24 794) | ||||
| TT3 | 1% (339) | 1% (371 of 24 794) | ||||
| FT4 | 33% (9301) | 33% (8125 of 24 794) | ||||
| TT4 | 2% (478) | 1% (238 of 24 794) | ||||
| TSH | 44% (12 336) | 51% (12 526 of 24 794) | ||||
| Willis and Datta,41 UK | An average of 950 patients and 309 thyroid profiles per month | Intervention(s): E+G Measure(s): mean (SD) number of TFT profiles per admission | 0.32 (0.05) | 0.08 (0.01) | Significant decrease in the number of requested thyroid profiles (p<0.001). Across all tests, a significant change between the total number of sets requested per admission before (7.5 (0.87)) and after the intervention (5.9 (0.33)), p<0.001. | |
*Approximate reading off a graph.
C, control group; CBC, complete blood count; CFP, changes to funding policy; CK, creatinine kinase; CV, coefficient of variation; DRTSH, directed thyroid testing algorithm; E, education; ED,emergency department; EM, educational memorandum; ETR, effective thyroxin ratio; FB, feedback; FBC, feedback on cost; FBY, feedback on yield; FT3, free tri-iodothyronine; FT4, free thyroxine; FTI, free thyroid index; G, guidelines/protocol; GCR, guideline conformity rate, the proportion of TFTs ordered in accordance with the guidelines; GP, general practitioner; I, Intervention group; LDH, lactic dehydrogenase isoenzyme; NA, not available; NR, not reported; PMC, pocket memory card; PMS, protocol management system; R, reminders; T3 (RIA), tri-iodothyronine radioimmunoassay; T3RU, tri-iodothyronine resin uptake; T4 (RIA), thyroxin radioimmunoassay; TFP, thyroid function panel; TFTs, thyroid function tests; TRF, test request form redesign; TSE, test-specific education; TSH, thyroid-stimulating hormone; TT3, total tri-iodothyronine; TT4, total thyroxin.