Objective: Meaning‐centered group psychotherapy for cancer survivors (MCGP‐CS) is an effective intervention to improve personal meaning, psychological well‐being, and depressive symptoms until 6 months after the intervention. In this study, the long‐term effects of MCGP‐CS (i.e., at 1‐ and 2‐year follow‐up) on meaning, psychological well‐being and posttraumatic growth were assessed, in comparison to supportive group psychotherapy (SGP) and care as usual (CAU). Methods: Cancer survivors (n = 170) were randomized into MCGP‐CS, SGP, or CAU. Assessments were scheduled at baseline, 1 week, 3 months, 6 months, 1 year, and 2 years postintervention. Outcome measures were the Personal Meaning Profile, Ryff's Scales of Psychological Well‐Being (SPWB), the Posttraumatic Growth Inventory, and their subscales. Linear mixed models (LMM) were used and results were both reported on an intention‐to‐treat (ITT) basis, as well as for intervention completers only. Results: LMM and post hoc analyses with Bonferroni correction revealed that MCGP‐CS participants reported more improvement on positive relations (subscale of SPWB) than CAU participants of 2‐year postintervention (ITT analysis, Cohen's d =.82). Completers also reported more personal growth (subscale of SPWB) after MCGP‐CS than after SGP 1‐year postintervention (Cohen's d =.94). No long‐term effects were found on the other outcome measures. Conclusions: In the 2 years after MCGP‐CS, the short‐term significant effects on personal meaning and most positive effects related to psychological well‐being faded. However, MCGP‐CS had a long‐term positive effect on positive relations with others and on survivors' sense of personal growth. Trial registration: Netherlands Trial Register: NTR3571
Keywords: cancer; cancer survivors; depression; follow‐up studies; group psychotherapy; intention‐to‐treat analysis; oncology; outcome assessment; psychological adaptation; psychological stress
Many cancer survivors encounter physical hindrances and are confronted with psychosocial and existential problems, also years after curative treatment is completed.[[
There is evidence that MCGP and MCGP‐CS are effective in enhancing a sense of meaning, psychological well‐being, and reducing depressive symptoms.[[
Several other types of existential interventions have been developed,[[
The aim of this study is to investigate the long‐term follow‐up results of the RCT on the efficacy of MCGP‐CS by Van der Spek et al.[
This study is an extension of a multicenter RCT on the efficacy of MCGP‐CS compared to SGP and CAU with three follow‐up assessments: postintervention and at 3‐ and 6‐month follow‐ups. In the present study, assessments were added at 1‐ and 2‐year follow‐ups. To limit participant burden, only personal meaning, psychological well‐being, and posttraumatic growth were assessed at the long‐term follow‐ups. The study protocol and extension were approved by the Medical Ethics Committee of the Leiden University Medical Center and the trial was registered in the Netherlands Trial Register (NTR3571).
Details of the study procedure can be found in the previous report on the efficacy of MCGP‐CS.[
An independent researcher prepared a computer‐generated randomization table with random block sizes and made a list of sequentially numbered allocations. Participants were placed in a group, and when a consecutive group had 7 to 10 participants, the independent researcher allocated the group to a study arm.
MCGP‐CS is a manualized intervention consisting of eight weekly 2‐hour sessions.[
SGP is a manualized intervention that aims to help survivors cope better with the cancer‐related difficulties.[
The primary outcome measure was personal meaning, measured as the total score of the Personal Meaning Profile (PMP).[[
The 49‐item Dutch version of the Ryff's Scales of Psychological Well‐Being (SPWB) was used to measure psychological well‐being.[[
Posttraumatic growth was measured using the total score of the Posttraumatic Growth Inventory.[[
A study‐specific questionnaire was used to obtain sociodemographic characteristics. Clinical characteristics were retrieved from medical records. Uptake of psychological treatment was measured at baseline and all follow‐up assessments, except postintervention, using the items about psychiatric and psychological treatment of the Treatment Inventory of Costs in Patients with psychiatric disorders.[
Linear mixed models (LMM) with fixed effects for study arm, time, and their two‐way interaction, as well as a random intercept for subjects, were used to investigate the differences in the course of the outcome measures over time in the three study arms. A correction was made for patient charactersitics if there were significant baseline differences across study arms. Also, analyses were corrected for the baseline scores of outcome measures in the case of significant differences between study arms at baseline. Results were reported on an ITT basis and for participants who attended six, seven, or all therapy sessions (completers).
If the course of an outcome measure differed significantly over time between the study arms, post hoc analyses were performed to assess which two groups differed significantly, using LMM, and between which points in time, using independent‐samples t tests. Post hoc analyses were corrected for multiple testing by Bonferroni's correction. Cohen's d effect sizes were calculated by dividing the difference in change since baseline between the study arms by the pooled SD, calculated at all separate follow‐up time points. Effect sizes of 0.2 were categorized as small, 0.5 as medium, and 0.8 as large.
As sensitivity analyses, all analyses were repeated without participants (a) who received psychological treatment during follow‐up and (b) who faced cancer recurrence during follow‐up. Analyses were performed in SPSS 24 and a two‐sided P value < .05 was considered to indicate statistical significance.
Basic information about the participant flow during the recruitment period and drop‐out in various phases of the study can be found in Figure and is published in more detail elsewhere.[
Sociodemographic and clinical participant characteristics are displayed in Table. Overall, most participants were female, in a relationship, and diagnosed with early stage breast cancer. Most completed the main cancer treatment about 1.5 year ago, and 80 (47%) still had hormonal therapy. In total, 29 (23%) participants received additional psychological treatment during follow‐up, 13 (8%) participants faced cancer recurrence, and 3 (2%) participants died.
Participant characteristics
MCGP (n = 57) SGP (n = 56) CAU (n = 57) n % n % n % Age (M, SD, range) 59 11 (32‐81) 56 9 (41‐80) 57 10 (37‐83) .34 Sex (female) 40 70 49 88 51 90 .012 Marital status (single) 12 21 9 16 13 23 .65 Level of education .16 Low 18 32 9 16 17 30 Medium 20 35 25 45 15 26 High 19 33 22 39 25 44 Religion .18 Christian 23 40 32 57 30 53 No religion 34 60 24 43 27 47 Past psychological treatment .53 In the last year 12 21 11 20 7 13 >1 year ago 21 37 21 37 17 31 Never 24 42 24 43 31 56 Psychological treatment during follow‐up 12 21 9 16 8 14 .61 Other negative life event in past 2 years (yes) 27 47 31 55 32 56 Type of cancer .071 Breast 30 53 40 71 42 74 Colon 15 26 12 21 10 18 Other 12 21 4 7 5 9 Type of treatment Surgery 57 100 56 100 56 98 .37 Radiation 31 54 32 57 33 58 .92 Chemotherapy 26 46 34 61 36 63 .12 Hormonal therapy 22 39 28 50 30 53 .28 Months since last cancer treatment (median, range) 19 6‐58 16 5‐52 19 3‐55 .97 Cancer recurrence 3 5 5 9 5 10 .70 Mortality 1 2 2 4 0 0
1 Abbreviations: CAU, care as usual; MCGP, meaning‐centered group psychotherapy; SGP, supportive group psychotherapy.
2 * P < .05.
Significant differences between the three study arms in the course of the outcome measures over the period of 2‐year follow‐up were found on the primary outcome: personal meaning (PMP; F[
Baseline, postintervention, and long‐term results of LMM analyzing treatment outcome
Short‐term Long‐term Baseline (T0) 1‐Week postintervention (T1) 1‐Year follow‐up (T4) 2‐Year follow‐up (T5) MCGP, SGP, CAU, MCGP, SGP, CAU, MCGP, SGP, CAU, MCG, SGP, CAU, PMP Total score 59 (16) 61 (13) 59 (12) 62 (16) 63 (13) 57 (14) 59 (15) 61 (14) 58 (13) 59 (17) 63 (12) 58 (11) .030* .011* Goal‐orientedness 69 (20) 71 (17) 72 (17) 74 (20) 72 (16) 63 (23) 66 (17) 69 (18) 66 (18) 66 (20) 73 (17) 68 (16) <.001** <.001** SPWB Positive relations 4.1 (1.0) 4.5 (1.0) 4.5 (0.83) 4.4 (1.0) 4.7 (0.95) 4.4 (0.93) 4.4 (1.1) 4.6 (1.0) 4.5 (1.0) 4.4 (1.1) 4.6 (1.1) 4.3 (1.1) .022* .013* Personal growth 4.2 (0.75) 4.4 (0.59) 4.3 (0.60) 4.4 (0.68) 4.4 (0.56) 4.3 (0.62) 4.4 (0.75) 4.3 (0.57) 4.3 (0.71) 4.2 (0.72) 4.3 (0.58) 4.3 (0.66) .061 .029* Purpose in life 4.1 (0.89) 4.3 (0.77) 4.4 (0.62) 4.4 (0.89) 4.3 (0.80) 4.3 (0.65) 4.2 (0.84) 4.3 (0.81) 4.4 (0.66) 4.3 (0.74) 4.3 (0.88) 4.3 (0.61) .028* .025*
- 3 Abbreviations: CAU, care as usual; ITT, intention‐to‐treat; MCGP, meaning‐centered group psychotherapy; PMP, Personal Meaning Profile; SGP, supportive group psychotherapy; SPWB, Scales of Psychological Well‐Being.
- 4 Only significant results displayed.
- 5 Corrected for baseline score.
- 6 * P < .05; ** P < .005.
Post hoc LMM analyses with Bonferroni correction did not show a significant difference between two of the study arms in the course of personal meaning (PMP total score) and purpose in life (SPWB) from baseline to 2‐year follow‐up (Table). Stronger long‐term treatment effects of MCGP‐CS compared to CAU were found on goal‐orientedness (PMP; F[
Post hoc analyses: LMM analyzing difference between two study arms, and treatment effect postintervention and at long‐term follow‐up
LMM analyses Short‐term Long‐term From baseline to 2‐years follow‐up Postintervention vs baseline 1‐Year follow‐up vs baseline 2‐Years follow‐up vs baseline MCGP‐SGP MCGP‐CAU SGP‐CAU MCGP‐SGP MCGP‐CAU MCGP‐SCP MCGP‐CAU MCGP‐SGP MCGP‐CAU Cohen's Cohen's Cohen's Cohen's Cohen's Cohen's Intention‐to‐treat PMP Total score 1.00 .12 .17 Goal‐orientedness 1.00 <.001** .055 1.07, <.001** 0.12, 1.00 −0.04, 1.00 SPWB Positive relations 1.00 .025* .91 0.59,.008* 0.41,.21 0.82,.005* Purpose in life .22 .080 1.00 Completers SPWB Personal growth .020* .28 1.00 0.65,.012* 0.94,.007* 0.34,.68
- 7 Abbreviations: MCGP: meaning‐centered group psychotherapy; SGP: supportive group psychotherapy; CAU: care as usual; PMP: Personal Meaning Profile; SPWB: Scales of Psychological Well‐Being.
- 8 LMM analyses are corrected for baseline score.
- 9 * P < .05; ** P < .005.
Between‐group Cohen's d effect sizes of MCGP‐CS compared to CAU on goal‐orientedness (PMP) were large and significant (d = 1.07, P < .001) when comparing the posttreatment assessment with baseline assessment, but not on the longer‐term assessments. Effect sizes of MCGP‐CS compared to CAU on positive relations (SPWB) remained medium to large during the 2‐year follow‐up period and were significant when comparing the postintervention (T1; d =.59, P =.008) and 2‐year follow‐up (T5; d =.82, P =.005) assessment with baseline.
For completers, the results were largely comparable (Table). Significant differences between study arms in the course of the outcome measure were found for personal meaning (PMP total score), goal‐orientedness (PMP), positive relations (SPWB), and purpose in life (SPWB). An additional significant result was found for personal growth (SPWB; F[
Post hoc analyses with Bonferroni correction did not reveal significant differences between two of the study arms for personal meaning (PMP total score) and purpose in life (SPWB). However, both MCGP‐CS participants (F[
Compared with ITT analyses, the effect sizes of MCGP‐CS on goal‐orientedness (PMP) and positive relations (SPWB) were slightly larger. Effect sizes comparing the change in personal growth between baseline and the assessments postintervention (d =.65, P =.012), 3‐month follow‐up (d =.64, P =.017), and 1‐year follow‐up (d =.94, P =.007) were medium to large in favor of MCGP‐CS.
Both long‐term effects of MCGP‐CS on positive relations (SPWB; T5; d =.86, P =.010; compared to CAU) and personal growth (SPWB; T4; d =.76, P =.007; compared to SGP) remained significant when repeating the analyses without participants who received psychological treatment in the period from 4 weeks preceding the study to 2‐year follow‐up. In addition, at 2‐year follow‐up, MCGP‐CS participants reported more inner strength (SPWB) than CAU participants (d =.91, P =.007). No significant long‐term effects were found when repeating the analysis without participants who faced cancer recurrence during follow‐up.
In the present study, the effects of MCGP‐CS on personal meaning, psychological well‐being, and posttraumatic growth over a period of 2 years were compared to the effects of SGP and CAU. A previous study[
It is striking that none of the sources of meaning investigated in this study (eg, goal‐orientedness) were significantly affected by MCGP‐CS in the long‐term. The few long‐term effects that were identified all occurred on the measure of psychological well‐being (SPWB). It is possible that the SPWB is more sensitive for change than the measure that was used for personal meaning (PMP). An alternative explanation may be that the long‐term improvements in the area of psychological well‐being were not strong enough to be translated into an enhanced sense of meaning. MCGP‐CS's few long‐term effects on psychological well‐being were slightly stronger when analyzing completers only and without participants who received other psychological treatment during the follow‐up period. No long‐term effects were found when participants who faced cancer recurrence during follow‐up were left out. Further research is not only needed to validate these long‐term findings, but should also address the question how these long‐term intervention effects interact with other major events in life.
The long‐term results of MCGP‐CS seem to be in line with the results of previous studies on long‐term effects of existential interventions. Overall, these effects seem to be quite modest. However, while some other studies did not find significant differences between the long‐term effects of an existential intervention and a non‐meaning‐focused intervention[[
MCGP‐CS is a useful addition to the current mental health care available in the oncology field. It is a brief intervention that is effective and cost‐effective.[[
A strength of this study is its conservative ITT analyses with Bonferroni correction. The statistical methods decrease the chance of false positive findings, lending more credibility to the effects that were found. Yet, the possibility of chance findings could not be ruled out and the significant long‐term effects should be interpreted tentatively; especially, because some results appeared to be inconsistent. MCGP‐CS participants reported better positive relations (SPWB) at long term, but did not report that these relations became a stronger source of personal meaning (PMP) for them. Furthermore, personal growth was better after MCGP‐CS compared to SGP, but not compared to CAU, and only for completers of the intervention. In addition, there are no clear criteria for minimal important difference on the outcome measures used in this study, so it is unknown to what extent the significant differences are clinically meaningful.
Another limitation of this study is the omission of a measure of depressive symptoms at 1‐ and 2‐year follow‐up. The decision about which outcome measures to maintain at follow‐up was made before the short‐term results became available. However, when these results became available, an interesting finding was that symptoms of depression were significantly decreased after MCGP‐CS compared to CAU, but only at 6‐month follow‐up. Unfortunately, in the present long‐term study, we could not confirm whether this effect remained after 1 and 2 years.
In the 2 years after MCGP‐CS, there was a decay of the short‐term positive effect on personal meaning and most positive effects related to psychological well‐being. However, MCGP‐CS had a long‐term positive effect on positive relations with others and on survivors' sense of personal growth.
The study was funded by the Dutch Cancer Society/Alpe d'HuZes/KWF Kankerbestrijding Fund, grant‐number 4864, to I.M. Verdonck‐de Leeuw.
K.H., B.L.W., and P.C. have nothing to disclose. N.v.d.S. and I.V.L. report grants form Dutch Cancer Society, during the conduct of the study. W.B. receives royalties from the sale of his manuals and textbook on MCP from Oxford University Press.
All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and national research committee (Medical Ethics Committee of the Leiden University Medical Center, P10.241) and with the 1964 Helsinki declaration and its later amendments.
The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.
GRAPH: Table S1. Baseline, postintervention, and long‐term results of linear mixed models analyzing treatment outcome.
By Karen Holtmaat; Nadia Spek; Birgit Lissenberg‐Witte; William Breitbart; Pim Cuijpers and Irma Verdonck‐de Leeuw
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