Nurse-led Medicines' Monitoring in Care Homes: a Process Evaluation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Nurse-led Medicines' Monitoring in Care Homes: a Process Evaluation (NCT03110471), a registered phase not stated study. The primary outcome is Number of Participants With Adverse Drug Reactions (ADRs) Treated.

2. Clinical Question

The record’s broad question is therefore both about resident-level detection and treatment of adverse drug reactions and about the practical conditions needed to sustain structured monitoring. These are related but different kinds of evidence. A count of residents with treated reactions would describe an observed clinical process, while interviews, observations and reflective accounts would address experiences and implementation. The registry record does not report findings from those qualitative activities or a numerical result for the primary outcome.

3. Trial Design

The registry identifies this as a completed process evaluation sponsored by Swansea University. The study started on 2017-03-01, had a primary completion date of 2018-03-30, and lists enrollment as 60. The enrollment figure is a registry entry; details about the number who contributed to each activity or outcome are not reported in the registry record.

The study description presents a before-and-after observational approach across 10 care homes. It describes observing changes in the detection and management of adverse drug reactions between usual care and administration of the West Wales Adverse Drug Reaction Profile. The care-home groups are described as having the same intervention. The record does not describe a randomized allocation, and it explicitly cautions that the arms are not a like-for-like control comparison. The allocation method is not stated.

The planned process evaluation included contributions from participants in earlier research, 5 newly recruited care homes, and stakeholders including care-home managers, carers, healthcare professionals and service users. Interviews, observations and reflective diaries or accounts were described as ways to examine experiences and implementation. The record does not report how many interviews or observations took place, which individuals contributed, or the findings from these activities.

The primary resident outcome was the number of participants with adverse drug reactions that were treated, with a stated timeframe of 6 months. Additional listed outcomes concern time for Profile administration, problems identified, changes to care by nurses, pharmacist recommendations for prescription review, and drug interactions. These measures address different aspects of monitoring, but numerical results for them are not reported in the registry record. The record also does not provide a detailed schedule of assessments or explain how observation periods were assigned.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Observation of residents. Service providers and users were not observed: they gave interviews.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: Baseline data not collected on the service providers and users.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Adverse Drug Reactions (ADRs) Treated, measured over 6 months.

The primary endpoint is the number of observed residents with an adverse drug reaction for which action was taken to correct the problem. The registry describes adverse drug reactions as those listed in the British National Formulary and manufacturers’ datasheets. Its definition focuses not simply on identifying a possible reaction, but on a reaction followed by corrective action.

This endpoint is relevant to a medicines-monitoring process evaluation because it represents a step beyond screening: the measure concerns residents for whom a problem was identified and acted upon. It can therefore describe whether monitoring is associated with recognition and management of reactions in the observed care-home setting. The record does not define what counted as corrective action, how reactions were attributed to medicines, or how disagreements about classification were resolved.

The endpoint is a count of participants with an event, rather than a reported measure of the severity of reactions or the size of any change in health status. To interpret a count as a comparison, readers would also need the corresponding observation denominators, timing, and a clear account of how residents contributed to each period. Those details and the primary outcome results are not reported in the registry record. The endpoint should therefore be read as the planned measure, not as evidence that a particular number of residents experienced treated reactions.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods should be interpreted in light of the study design and the information actually reported. In this record, the design is described as observational and before-and-after. The allocation method is not stated, and the record says the arms are not a like-for-like control comparison. These features limit the conclusions that can be drawn from a simple contrast between periods.

What does the primary count represent?

The primary measure counts participants who had an adverse drug reaction for which corrective action was taken. At the resident level, this can be understood as an event indicator: a resident either meets the endpoint definition or does not. Summing such indicators gives a count. For a count to be interpretable in comparison, its denominator and observation period also matter. For example, the same count could have different meaning in groups with different numbers of residents observed or different observation time. The registry states a timeframe of 6 months, but does not report the primary counts or the corresponding outcome denominators by period.

General statistical explanation: a count can be presented descriptively, while a comparison may use a model suited to the outcome and design. The choice depends on how observations are organized, whether residents contribute more than one observation, how follow-up is handled, and whether counts are sparse or variable. The registry record does not report a statistical model, an adjustment set, or the data structure used for analysis. No particular analysis can therefore be attributed to this evaluation.

Why does the before-and-after design matter?

In a before-and-after study, outcomes observed in one period are compared with outcomes in another. A within-setting comparison may be useful for describing practice over time, but the periods are not automatically exchangeable. Changes in the mix of residents, staff, prescribing, documentation, or other care processes could coincide with implementation. Without random assignment or a suitable comparison strategy, these factors can complicate attribution. General statistical explanation: adjustment can sometimes account for measured differences, but cannot guarantee removal of bias from unmeasured or poorly measured factors. Whether adjustment was undertaken is not reported in the registry record.

Repeated observations also require attention to dependence. Residents within the same care home may share staff and processes, so their outcomes may be more alike than outcomes from unrelated settings. General statistical explanation: methods that account for clustering can avoid treating correlated observations as fully independent. The registry record does not report whether clustering by care home or repeated observations were addressed analytically.

How should uncertainty be considered?

A confidence interval is a range of values compatible with the data and the assumptions of the analysis; it expresses uncertainty around an estimate. A point estimate alone does not show how precisely a difference has been measured. The registry record reports no primary-outcome estimate, confidence interval, or statistical test. The precision of the endpoint and the evidence for a difference therefore cannot be evaluated from the registry record.

The record includes a planning illustration framework based on a stated fraction of an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. For non-time-to-event outcomes, the framework describes participants per arm for 80% power; time-to-event illustrations are described in terms of total events. These are planning assumptions, not a report of the original design calculation or observed power. No numerical planning illustration is reported in the registry record, and the original sample-size justification is not reported in the registry record. Because the design is not described as randomized, the equal-allocation assumption in a planning illustration should not be mistaken for the actual study design.

General statistical explanation: over-dispersion occurs when counts vary more than a model’s basic assumptions expect. If present, it can make standard errors too small unless the analysis accounts for it. The registry record does not report a dispersion estimate or a model for the count outcome, so it is not possible to say whether over-dispersion was assessed or relevant in the analysis.

What can secondary outcomes add?

The registry lists secondary measures of administration time, problems identified, nurse-led changes to care, pharmacist recommendations for prescription review, and drug interactions. Together, these measures concern workload, identification and subsequent management. Each answers a different question and may have a different unit or distribution. For instance, an administration-time measure is not interpreted in the same way as a count of identified problems. Numerical results and analysis methods for these measures are not reported in the registry record.

General statistical explanation: a study that examines multiple outcomes creates multiple opportunities to observe an apparently notable result by chance. Statistical plans may address this by specifying a primary outcome, distinguishing confirmatory from exploratory analyses, or adjusting for multiple comparisons. The registry record does not report a multiplicity strategy, a detailed analysis plan, or the results of statistical tests. It is therefore not possible to assess how multiple outcomes were handled.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Whole Study - Observed Residents")
n      <- c(30)
events <- c(30)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Whole Study - Observed Residents  30  30  100.0  88.4  100.0  88.6  100.0  88.8  99.9

11. Multiplicity, Missing Data and Analysis Populations

The registry lists the primary outcome and five secondary outcomes, covering treated adverse drug reactions, Profile administration time, identified problems, changes to care by nurses, pharmacist recommendations for prescription review, and drug interactions. It does not report a prespecified hierarchy among the secondary outcomes or a method for accounting for multiple comparisons. Because no analyses or outcome results are reported, the record does not show whether any multiplicity procedure was used.

Missing-data methods and outcome-specific completeness are not reported in the registry record. It does not say whether all enrolled participants contributed to each outcome, how missing observations were handled, or whether any participants were excluded from particular analyses. The enrollment entry alone does not establish the number included in an analysis.

Analysis populations are also not described. The record does not specify a population defined by allocation, intervention exposure, completion of follow-up, or availability of outcome measurements. This is especially relevant to an observational before-and-after evaluation, where residents may be observed across different periods and the record does not explain how those observations were linked or summarized.

These omissions mean that readers cannot assess whether missingness, selective outcome reporting, or analysis choices may have affected the reported results. The registry lists zero analyses, and numerical findings for the primary and secondary outcomes are not reported in the registry record. No adjustment for multiplicity, missingness, or analysis population should be assumed.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry’s adverse-event fields list zero serious adverse events among 30 at risk, zero other adverse events among 30 at risk, and zero deaths. No serious adverse-event terms are listed. These entries should be read as the safety information recorded in the registry, not as a complete account of all possible medication problems or all outcomes of interest.

The safety fields are distinct from the primary endpoint. The primary endpoint concerns participants with adverse drug reactions for which action was taken to correct the problem, whereas the safety fields report adverse-event counts. The record does not provide definitions that would establish that these measures cover the same events. In particular, the zero entries in the safety fields should not be interpreted as a zero count for the primary outcome.

The registry does not report additional detail about event ascertainment, severity classification, follow-up completeness, or the relationship between safety events and the monitoring intervention. The listed entries can therefore describe what was recorded, but do not by themselves establish that no adverse drug reactions occurred or that the Profile changed safety outcomes.

13. What the Result Does, and Does Not, Mean

The registry record establishes that a completed observational process evaluation was registered, with an enrollment entry of 60 and a stated focus on nurse-led use of the West Wales Adverse Drug Reaction Profile in care homes. It describes intended attention to the detection and management of adverse drug reactions and to the practical experience of medication monitoring. It also identifies a resident-level primary outcome and several implementation-related secondary outcomes.

It does not establish the size or direction of a change in the number of residents with treated adverse drug reactions. The primary outcome result is not reported in the registry record, nor are numerical results for the secondary outcomes. The record provides no estimate of an effect, confidence interval or test result. Statistical significance and precision therefore cannot be judged.

The observational before-and-after design can be useful for understanding how monitoring is introduced in routine settings, but it does not by itself isolate the effect of the Profile from other changes over time. The record specifically cautions that the arms are not a like-for-like control comparison. Findings from interviews, observations or reflective accounts could add information about implementation, but those findings are not reported in the registry record.

The zero adverse-event entries describe the safety information recorded, not the primary endpoint. They should not be treated as evidence that no adverse drug reactions occurred or that the monitoring approach altered their frequency. The brief summary’s statements about earlier research are background claims, not results of this evaluation.

Accordingly, the record supports a description of the study’s aims and design, but not a quantitative conclusion about the effect of Profile use. It also does not establish whether implementation was sustained or what barriers and facilitators were found. Those conclusions would require outcome and process findings that are not reported in the registry record.

14. Why This Trial Matters Statistically

This evaluation is statistically relevant because it brings together clinical process measures and questions about implementation in routine care homes. An intervention can be studied not only by asking whether an outcome changes, but also by examining whether staff can use the approach, what practice changes accompany it, and what may support continued use. The registry identifies those implementation questions alongside a resident-level measure of treated adverse drug reactions.

The design illustrates why a before-and-after comparison needs careful interpretation. Observed changes can be informative about practice, but without a like-for-like comparison they may reflect differences between periods as well as any contribution from the monitoring approach. This matters particularly when the intervention is delivered within care homes, where staffing, residents and local processes can shape observed outcomes.

The listed outcomes also show why a single count may not capture the whole process. Monitoring time, identified problems, changes to care, pharmacist recommendations and drug interactions address different stages or aspects of medicines management. Their usefulness depends on clear definitions, denominators and analysis methods, none of which are fully reported for these outcomes in the registry record.

Finally, the record demonstrates the distinction between registration and an interpretable results report. It documents the intended question, setting and measures, but does not provide the numerical outcome analyses needed to assess effect or precision. Keeping that distinction clear prevents the study’s rationale, design, and safety entries from being mistaken for quantitative evidence of a treatment effect.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The most direct limitation for interpretation is the absence of reported numerical results for the primary and secondary outcomes. The record lists zero analyses, and does not provide estimates, uncertainty intervals or test results. It is therefore not possible to assess the observed change in treated adverse drug reactions or the precision of any comparison.

The study is described as observational and before-and-after, with no allocation method stated and an explicit warning that the arms are not a like-for-like control comparison. The registry record does not describe how differences between periods or care homes were handled. It also does not report whether observations were linked at the resident level, how clustering within care homes was addressed, or how outcome denominators were defined.

Details needed to evaluate the process component are also absent from the registry record. It does not report the number of people who participated in interviews, observations or reflective accounts, how qualitative material was analyzed, or the findings. The contribution of the 5 newly recruited care homes to the analyses is not specified. Eligibility criteria, resident characteristics and outcome completeness are not reported.

The record does not describe the statistical analysis plan, a sample-size justification, missing-data methods, analysis populations, or a multiplicity approach. It also does not clarify what counted as corrective action for the primary endpoint. These gaps limit reproducibility and make it difficult to determine how closely the registered aims correspond to the analyses conducted.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Nurse-led Medicines' Monitoring in Care Homes: a Process Evaluation — NCT03110471.
• Registry record last updated 2020-06-24; status last verified 2020-06.
• Results first posted 2020-06-24.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

This completed registry record concerns a process evaluation of nurse-led medicines monitoring using the West Wales Adverse Drug Reaction Profile in care homes. It lists Swansea University as sponsor, enrollment of 60, and a primary outcome of the number of observed residents with adverse drug reactions treated during a stated 6 months. The design is described as observational and before-and-after, and the record cautions that the arms are not a like-for-like control comparison.

The evaluation aimed to examine implementation and sustainability through interviews, observations and reflective accounts, alongside resident and care-process outcomes. The registry lists five secondary outcomes and records safety entries of zero serious adverse events, zero other adverse events and zero deaths.

Numerical results for the primary and secondary outcomes, analysis methods, missing-data handling and qualitative findings are not reported in the registry record. The entry therefore describes the study’s aims and design but does not support a quantitative estimate of the effect of the monitoring approach.